阅读说明：本技术 H形电容结构的垂直型存储器及其制备方法 (Vertical memory with H-shaped capacitor structure and preparation method thereof ) 是由 刘金营 于 2021-09-02 设计创作，主要内容包括：本发明提供一种H形电容结构的垂直型存储器及其制备方法,通过在第一逻辑单元的漏极区及第二逻辑单元的漏极区的外周形成电容器存储单元,且第一逻辑单元漏极区外周的电容器存储单元与第二逻辑单元漏极区外周的电容器上下结合使整个电容器存储单元呈H形圆筒结构,有效增大了电容器的面积,提高电容器的电荷存储能力,可有效提高存储器读取精确度和电荷保存时间。通过第一逻辑单元及第二逻辑单元控制电容器存储结构的读写,电容器存储单元负责存储电荷,第一逻辑单元及第二逻辑单元可独立或者联合的向电容器存储结构存储或读取数据。(The invention provides a vertical memory with an H-shaped capacitor structure and a preparation method thereof.A capacitor storage unit is formed at the periphery of a drain region of a first logic unit and the periphery of a drain region of a second logic unit, and the capacitor storage unit at the periphery of the drain region of the first logic unit and a capacitor at the periphery of the drain region of the second logic unit are combined up and down to enable the whole capacitor storage unit to be in an H-shaped cylindrical structure, so that the area of the capacitor is effectively increased, the charge storage capacity of the capacitor is improved, and the reading accuracy and the charge storage time of the memory can be effectively improved. The first logic unit and the second logic unit can independently or jointly store or read data to or from the capacitor storage structure.)

1. A preparation method of a vertical memory with an H-shaped capacitor structure is characterized by comprising the following steps:

providing a substrate;

forming a first logic unit laminated structure on the substrate, wherein the first logic unit laminated structure comprises a first source region, a first channel region and a first drain region which are sequentially stacked from bottom to top;

forming a sacrificial layer on the first logic unit laminated structure;

forming a second logic unit laminated structure on the sacrificial layer, wherein the second logic unit laminated structure comprises a second drain region, a second channel region and a second source region which are sequentially stacked from bottom to top;

patterning the second logic unit laminated structure, the sacrificial layer and the first drain electrode region with partial thickness to form a third laminated structure;

removing the sacrificial layer in the third stacked structure to form a gap between the first drain region and the second drain region;

sequentially depositing a first pole plate layer, a dielectric layer and a second pole plate layer on the surface of the third laminated structure, wherein the first pole plate layer, the dielectric layer and the second pole plate layer fill the gap;

patterning the first drain region, the first channel region and the first source region with the residual thickness to form a fourth laminated structure;

sequentially forming a first gate dielectric layer and a first gate metal layer surrounding the first channel region in the fourth laminated structure at the periphery of the first channel region to obtain a first logic unit gate-all-around structure;

removing the first plate layer, the dielectric layer and the second plate layer on the periphery of the second source region and the second channel region in the fourth laminated structure, wherein the remaining first plate layer, the dielectric layer and the second plate layer form a capacitor storage unit with an H-shaped cylindrical structure;

sequentially forming a second gate dielectric layer and a second gate metal layer surrounding the second channel region in the fourth laminated structure at the periphery of the second channel region to obtain a second logic unit gate-all-around structure;

forming a metal connection part electrically connected with the first gate metal layer, the second gate metal layer, the first source region and the second source region.

2. The method for fabricating the vertical type memory of the H-shaped capacitor structure as claimed in claim 1, wherein the step of removing the sacrificial layer in the third stacked structure comprises:

forming a first insulating layer around the third stacked structure;

patterning the third stacked structure based on the first insulating layer to form a common region in a vertical direction;

depositing a support layer on the common area so as to connect the support layer and the third laminated structure together;

removing the remaining first insulating layer;

and removing the sacrificial layer.

3. The method for fabricating the vertical-type memory of the H-shaped capacitor structure according to claim 2, further comprising a step of removing the support layer after forming the first, dielectric and second plate layers.

4. The method as claimed in claim 1, wherein the step of forming the first logic cell gate-all-around structure comprises:

depositing a second insulating layer on the surface of the substrate;

depositing the first gate dielectric layer on the side wall of the fourth laminated structure;

and depositing the first gate metal layer on the side wall of the first channel region in the fourth laminated structure.

5. A vertical-type memory with an H-shaped capacitor structure, comprising:

a substrate;

the first logic unit laminated structure is positioned on the substrate and comprises a first source region, a first channel region and a first drain region which are sequentially stacked from bottom to top;

the second logic unit laminated structure is positioned on the first logic unit laminated structure and comprises a second drain region, a second channel region and a second source region which are sequentially stacked from bottom to top;

the capacitor storage unit comprises a first plate layer, a dielectric layer and a second plate layer, wherein the first plate layer is respectively contacted with the first drain electrode region and the second drain electrode region, the second plate layer is positioned at the periphery of the first plate layer, and part of the first plate layer, part of the second plate layer and part of the dielectric layer are filled between the first drain electrode region and the second drain electrode region, so that the capacitor storage unit is of an H-shaped cylindrical structure;

the first logic unit gate-all structure comprises a first gate dielectric layer and a first gate metal layer which surround the periphery of the first channel region;

the second logic unit gate-all structure comprises a second gate dielectric layer and a second gate metal layer which surround the periphery of the second channel region;

a metal connection part electrically connected to the first gate metal layer, the second gate metal layer, the first source region, and the second source region.

6. The H-shaped capacitor structure of vertical memory as claimed in claim 5, wherein: the first logic cell laminated structure comprises one of an NNN type logic cell laminated structure, a PPP type logic cell laminated structure, an NPN type logic cell laminated structure and a PNP type logic cell laminated structure; the second logic cell stack structure includes one of an NNN-type logic cell stack structure, a PPP-type logic cell stack structure, an NPN-type logic cell stack structure, and a PNP-type logic cell stack structure.

7. The H-shaped capacitor structure of vertical memory as claimed in claim 5, wherein: the dielectric layer is a laminated structure of a high-K layer, an insulating layer and the high-K layer, and the high-K layer is made of ZrO₂Or HfO₂The material of the insulating layer is Al₂O₃Or SiO₂The first and second pole plate layers are TiN layers.

8. The H-shaped capacitor structure of vertical memory as claimed in claim 5, wherein: an included angle theta is formed between the first gate metal layer and the second gate metal layer, and the value range of the included angle theta is more than or equal to 30 degrees and less than or equal to 180 degrees.

9. The H-shaped capacitor structure of vertical memory as claimed in claim 5, wherein: the substrate is an SOI substrate, the materials of the first source region, the first drain region, the second source region and the second drain region are SiC or Si, and the materials of the first channel region and the second channel region are Si or Ge.

10. The H-shaped capacitor structure of vertical memory as claimed in claim 5, wherein: the first gate dielectric layer comprises one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer and a zirconium oxide layer; the second gate dielectric layer comprises one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer and a zirconium oxide layer; the first gate metal layer comprises one or a combination of a TiN layer, a Ti layer, a TaN layer and a Ta layer; the second gate metal layer comprises one or a combination of a TiN layer, a Ti layer, a TaN layer and a Ta layer.

Technical Field

The invention belongs to the technical field of integrated circuit manufacturing, and particularly relates to a vertical memory with an H-shaped capacitor structure and a preparation method thereof.

Background

With the development of technology and the pursuit of miniaturization and multifunction devices, the size of integrated circuit devices is continuously shrinking, but limited by the limitations of the fabrication process and the basic laws of physics, the critical size of the devices is becoming more and more difficult to shrink, and the physical size of the integrated circuit devices approaches to the limit.

In recent years, vertical memories have been receiving attention because of their structural advantages, in which the size of the memory cells in the memories restricts the size of the entire memories. Increasing the capacitor area in a memory within a given size range currently presents a significant challenge.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a vertical memory with an H-shaped capacitor structure and a method for manufacturing the same, which are used to solve the problems of the prior art, such as a small capacitor area of the vertical memory.

In order to achieve the above and other related objects, the present invention provides a method for fabricating a vertical memory with an H-shaped capacitor structure, the method comprising the steps of:

providing a substrate;

forming a first logic unit laminated structure on the substrate, wherein the first logic unit laminated structure comprises a first source region, a first channel region and a first drain region which are sequentially stacked from bottom to top;

forming a sacrificial layer on the first logic unit laminated structure;

forming a second logic unit laminated structure on the sacrificial layer, wherein the second logic unit laminated structure comprises a second drain region, a second channel region and a second source region which are sequentially stacked from bottom to top;

patterning the second logic unit laminated structure, the sacrificial layer and the first drain electrode region with partial thickness to form a third laminated structure;

removing the sacrificial layer in the third stacked structure to form a gap between the first drain region and the second drain region;

sequentially depositing a first pole plate layer, a dielectric layer and a second pole plate layer on the surface of the third laminated structure, wherein the first pole plate layer, the dielectric layer and the second pole plate layer fill the gap;

patterning the first drain region, the first channel region and the first source region with the residual thickness to form a fourth laminated structure;

sequentially forming a first gate dielectric layer and a first gate metal layer surrounding the first channel region in the fourth laminated structure at the periphery of the first channel region to obtain a first logic unit gate-all-around structure;

removing the first plate layer, the dielectric layer and the second plate layer on the periphery of the second source region and the second channel region in the fourth laminated structure, wherein the remaining first plate layer, the dielectric layer and the second plate layer form a capacitor storage unit with an H-shaped cylindrical structure;

sequentially forming a second gate dielectric layer and a second gate metal layer surrounding the second channel region in the fourth laminated structure at the periphery of the second channel region to obtain a second logic unit gate-all-around structure;

forming a metal connection part electrically connected with the first gate metal layer, the second gate metal layer, the first source region and the second source region.

Optionally, the step of removing the sacrificial layer in the third stacked structure comprises:

forming a first insulating layer around the third stacked structure;

patterning the third stacked structure based on the first insulating layer to form a common region in a vertical direction;

depositing a support layer on the common area so as to connect the support layer and the third laminated structure together;

removing the remaining first insulating layer;

and removing the sacrificial layer.

Further, the step of removing the support layer is further included after the first pole plate layer, the dielectric layer and the second pole plate layer are formed.

Optionally, the step of forming the first logic cell gate all around structure includes:

depositing a second insulating layer on the surface of the substrate;

depositing the first gate dielectric layer on the side wall of the fourth laminated structure;

and depositing the first gate metal layer on the side wall of the first channel region in the fourth laminated structure.

The present invention also provides a vertical memory of an H-shaped capacitor structure, the vertical memory including:

a substrate;

the first logic unit laminated structure is positioned on the substrate and comprises a first source region, a first channel region and a first drain region which are sequentially stacked from bottom to top;

the second logic unit laminated structure is positioned on the first logic unit laminated structure and comprises a second drain region, a second channel region and a second source region which are sequentially stacked from bottom to top;

the capacitor storage unit comprises a first plate layer, a dielectric layer and a second plate layer, wherein the first plate layer is respectively contacted with the first drain electrode region and the second drain electrode region, the second plate layer is positioned at the periphery of the first plate layer, and part of the first plate layer, part of the second plate layer and part of the dielectric layer are filled between the first drain electrode region and the second drain electrode region, so that the capacitor storage unit is of an H-shaped cylindrical structure;

the first logic unit gate-all structure comprises a first gate dielectric layer and a first gate metal layer which surround the periphery of the first channel region;

the second logic unit gate-all structure comprises a second gate dielectric layer and a second gate metal layer which surround the periphery of the second channel region;

a metal connection part electrically connected to the first gate metal layer, the second gate metal layer, the first source region, and the second source region.

Optionally, the first logic cell stacked structure includes one of an NNN type logic cell stacked structure, a PPP type logic cell stacked structure, an NPN type logic cell stacked structure, and a PNP type logic cell stacked structure; the second logic cell stack structure includes one of an NNN-type logic cell stack structure, a PPP-type logic cell stack structure, an NPN-type logic cell stack structure, and a PNP-type logic cell stack structure.

Optionally, the dielectric layer is a stacked structure of a high-K layer, an insulating layer and the high-K layer, and the material of the high-K layer is ZrO₂Or HfO₂The material of the insulating layer is Al₂O₃Or SiO₂The first and second pole plate layers are TiN layers.

Optionally, an included angle θ is formed between the first gate metal layer and the second gate metal layer, and a value range of the included angle θ includes that θ is greater than or equal to 30 degrees and less than or equal to 180 degrees.

Optionally, the substrate is an SOI substrate, the materials of the first source region, the first drain region, the second source region, and the second drain region are SiC or Si, and the materials of the first channel region and the second channel region are Si or Ge.

Optionally, the first gate dielectric layer includes one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer and a zirconium oxide layer; the second gate dielectric layer comprises one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer and a zirconium oxide layer; the first gate metal layer comprises one or a combination of a TiN layer, a Ti layer, a TaN layer and a Ta layer; the second gate metal layer comprises one or a combination of a TiN layer, a Ti layer, a TaN layer and a Ta layer.

As described above, according to the vertical memory with the H-shaped capacitor structure and the method for manufacturing the same of the present invention, the capacitor storage unit is formed on the periphery of the drain region of the first logic unit and the drain region of the second logic unit, and the capacitor storage unit on the periphery of the drain region of the first logic unit and the capacitor on the periphery of the drain region of the second logic unit are vertically combined to make the whole capacitor storage unit have the H-shaped cylindrical structure, so that the area of the capacitor is effectively increased, the charge storage capability of the capacitor is improved, and the reading accuracy and the charge storage time of the memory can be effectively improved. The first logic unit and the second logic unit can independently or jointly store or read data to or from the capacitor storage structure.

Drawings

Fig. 1 is a process flow diagram illustrating a method for manufacturing a vertical memory with an H-shaped capacitor structure according to a first embodiment of the invention.

Fig. 2 to 33 are schematic structural diagrams showing steps in a method for manufacturing a vertical memory with an H-shaped capacitor structure according to a first embodiment of the invention; fig. 8, 9, 11, and 13 are schematic cross-sectional structures taken along a line cut at an AA position in fig. 7, fig. 10, 12, and 14 are schematic cross-sectional structures taken along a line cut at a BB position in fig. 7, fig. 31 is a schematic cross-sectional structure taken along a line cut at a CC position in fig. 30, fig. 32 is a schematic cross-sectional structure taken along a line cut at a DD position in fig. 30, and fig. 33 is a schematic side-view structure of fig. 30.

Description of the element reference numerals

100 substrate

101 bottom layer silicon

102 buried oxide layer

103 top layer silicon

210 first logic cell stack structure

211 first source region

212 first channel region

213 first drain region

213a part of the thickness of the first drain region

213b a first drain region of a remaining thickness

220 second logic cell stack structure

221 second drain region

222 second channel region

223 second source region

230 sacrificial layer

231 first insulating layer

232 support layer

233 gap

240 third layer stack

250 first plate layer

251 dielectric layer

252 second diode layer

260 fourth Stack Structure

270 first logic cell gate all around structure

271 first gate dielectric layer

272 first gate metal layer

280 second logic cell gate-all-around structure

281 second gate dielectric layer

282 second gate metal layer

290 metallic connection

291 diffusion barrier layer

292 metal layer

293 Metal connection hole

301 second insulating layer

302 third insulating layer

303 fourth insulating layer

304 fifth insulating layer

305 ohmic contact layer

S1-S12

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

Please refer to fig. 1 to 33. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation can be changed according to the actual requirement, and the layout of the components may be more complicated.

Example one

As shown in fig. 1, this embodiment provides a method for manufacturing a vertical memory with an H-shaped capacitor structure, where the method includes the following steps:

providing a substrate;

forming a first logic unit laminated structure on the substrate, wherein the first logic unit laminated structure comprises a first source region, a first channel region and a first drain region which are sequentially stacked from bottom to top;

forming a sacrificial layer on the first logic unit laminated structure;

forming a second logic unit laminated structure on the sacrificial layer, wherein the second logic unit laminated structure comprises a second drain region, a second channel region and a second source region which are sequentially stacked from bottom to top;

patterning the second logic unit laminated structure, the sacrificial layer and the first drain electrode region with partial thickness to form a third laminated structure;

removing the sacrificial layer in the third stacked structure to form a gap between the first drain region and the second drain region;

sequentially depositing a first pole plate layer, a dielectric layer and a second pole plate layer on the surface of the third laminated structure, wherein the first pole plate layer, the dielectric layer and the second pole plate layer fill the gap;

patterning the first drain region, the first channel region and the first source region with the residual thickness to form a fourth laminated structure;

sequentially forming a first gate dielectric layer and a first gate metal layer surrounding the first channel region in the fourth laminated structure at the periphery of the first channel region to obtain a first logic unit gate-all-around structure;

removing the first plate layer, the dielectric layer and the second plate layer on the periphery of the second source region and the second channel region in the fourth laminated structure, wherein the remaining first plate layer, the dielectric layer and the second plate layer form a capacitor storage unit with an H-shaped cylindrical structure;

sequentially forming a second gate dielectric layer and a second gate metal layer surrounding the second channel region in the fourth laminated structure at the periphery of the second channel region to obtain a second logic unit gate-all-around structure;

forming a metal connection part electrically connected with the first gate metal layer, the second gate metal layer, the first source region and the second source region.

In the embodiment, the capacitor storage units are formed at the peripheries of the drain regions of the first logic unit and the second logic unit, and the capacitor storage units at the periphery of the drain region of the first logic unit and the capacitor at the periphery of the drain region of the second logic unit are combined up and down to enable the whole capacitor storage unit to be in an H-shaped cylindrical structure, so that the area of the capacitor is effectively increased, the charge storage capacity of the capacitor is improved, and the reading accuracy and the charge storage time of the memory can be effectively improved. The first logic unit and the second logic unit can independently or jointly store or read data to or from the capacitor storage structure.

Specifically, fig. 2 to 33 are schematic diagrams showing results of steps in the process of manufacturing the vertical memory with the H-shaped capacitor structure. It should be noted that only the cell structure of 1 2T1C (i.e. 2 logic cells and 1 memory cell) is illustrated in this embodiment, and those skilled in the art can understand that a plurality of stacked cell structures of 2T1C may be included in the vertical memory.

Specifically, as shown in fig. 1 and 2, step S1 is performed to provide the substrate 100.

In this embodiment, the substrate 100 is an SOI substrate, that is, the substrate includes a bottom layer silicon 101, a buried oxide layer 102 and a top layer silicon 103, but the selection of the substrate 100 is not limited thereto, and may be specifically selected according to needs, for example, the substrate 100 may also be a silicon substrate, a sapphire substrate, a silicon carbide substrate, and the like, and is not limited herein.

As shown in fig. 1 and fig. 3, step S2 is performed to form a first logic cell stacked structure 210 on the substrate 100, wherein the first logic cell stacked structure 210 includes a first source region 211, a first channel region 212, and a first drain region 213 stacked in sequence from bottom to top.

As an example, the first logic cell stack structure 210 may include one or a combination of an NNN type logic cell stack structure, a PPP type logic cell stack structure, an NPN type logic cell stack structure, and a PNP type logic cell stack structure.

Specifically, the method for forming the first logic cell stack structure 210 may adopt an EPI method, but is not limited thereto. In this embodiment, the first logic cell stacked structure 210 is an N-type logic cell, that is, an NPN-type logic cell stacked structure, and in the first logic cell stacked structure 210, the first source region 211 and the first drain region 213 are both made of SiC, the first channel region 212 is made of Si, and doping of the first logic cell stacked structure 210 may be performed during an EPI growth process. Of course, according to the requirement, the first logic cell stacked structure 210 may also adopt an N-type logic cell having an NNN-type logic cell stacked structure, or the first logic cell stacked structure 210 may also be designed as a P-type logic cell, such as a PNP-type logic cell stacked structure or a PPP-type logic cell stacked structure, and the selection of the material and the type of the first logic cell stacked structure 210 is not limited thereto, and may be specifically selected according to the requirement, for example, the material of the first source region 211 and the first drain region 213 is Si, and the material of the first channel region 212 is Ge, which is not limited herein.

As shown in fig. 1 and 4, step S3 is performed to form a sacrificial layer 230 on the first logic cell stack structure 210.

The sacrificial layer 230 includes, for example, a SiGe layer prepared by an EPI method, but is not limited thereto, and other materials with a relatively high etching selectivity may be selected.

As shown in fig. 1 and 5, step S4 is performed to form a second logic cell stacked structure 220 on the sacrificial layer 230, wherein the second logic cell stacked structure 220 includes a second drain region 221, a second channel region 222, and a second source region 223 sequentially stacked from bottom to top.

Specifically, the method of forming the second logic cell stack structure 220 may adopt an EPI method, but is not limited thereto. In this embodiment, the second logic cell stacked structure 220 is an N-type logic cell, that is, an NPN-type logic cell stacked structure identical to the first logic cell stacked structure 210, and in the second logic cell stacked structure 220, the second drain region 221 and the second source region 223 are both made of SiC, the second channel region 222 is made of Si, and doping of the second logic cell stacked structure 220 may be performed during an EPI growth process. Of course, according to the requirement, the second logic cell stacked structure 220 may also adopt an N-type logic cell having an NNN-type logic cell stacked structure, or the second logic cell stacked structure 220 may also be designed as a P-type logic cell, such as a PNP-type logic cell stacked structure or a PPP-type logic cell stacked structure, and the selection of the material and the type of the second logic cell stacked structure 220 is not limited thereto, and may be specifically selected according to the requirement, for example, the material of the second drain region 221 and the second source region 223 is Si, and the material of the second channel region 222 is Ge, which is not limited herein.

As shown in fig. 1 and fig. 6, step S5 is performed to pattern the second logic cell stacked structure 220, the sacrificial layer 230, and a portion of the first drain region 213a to form a third stacked structure 240.

As an example, the third stacked structure 240 may be formed by using a dry etching process. In this step, the first drain region 213 is selectively etched by a partial thickness, so as to form a physical isolation between the capacitor storage unit formed at the periphery of the first drain region 213 and the first channel region 212.

As shown in fig. 1 and fig. 15, step S6 is performed to remove the sacrificial layer 230 in the third stacked structure 240, so as to form a gap 233 between the first drain region 213 and the second drain region 221.

As a specific example, the step of removing the sacrificial layer 230 in the third stacked structure 240 includes:

as shown in fig. 7, first, a first insulating layer 231 is formed around the third stacked structure 240;

as shown in fig. 9 and 10, the third stacked structure 240 is then patterned based on the first insulating layer 231 to form a common region in a vertical direction. The common area is subsequently used as an area for forming a support layer for supporting the third stacked structure 240;

as shown in fig. 11 to 14, a support layer 232 is deposited on the common area, so that the support layer 232 and the third stacked structure 240 are connected together; specifically, as shown in fig. 11 and 12, a support layer 232 is formed on the sidewalls of the first insulating layer, as shown in fig. 13 and 14, and then the support layer 232 outside the common region is removed, and only the support layer 232 of the common region is remained;

as shown in fig. 13 and 14, the remaining first insulating layer 231 is removed;

as shown in fig. 15, the sacrificial layer 230 is finally removed to form the gap 233. The sacrificial layer 230 may be removed by wet etching, and the etching solution may include, but is not limited to, an HF solution, and may be specifically selected according to the type of the sacrificial layer 230.

By removing the sacrificial layer 230 by this method, the second logic unit stack structure 220 can be supported without collapsing. Therefore, in fig. 15, the second logic cell stack 220 is not suspended, but supported by the support layer 232. In this embodiment, the material of the supporting layer 232 is selected to be silicon oxide, and the material of the first insulating layer is TEOS, but the material is not limited thereto, and may be adaptively changed according to needs, and is not limited herein.

As shown in fig. 1 and 16, step S7 is performed to sequentially deposit a first pole plate layer 250, a dielectric layer 251 and a second pole plate layer 252 on the surface of the third stacked structure 240, wherein the first pole plate layer 250, the dielectric layer 251 and the second pole plate layer 252 fill the gap 233.

In this step, the capacitor storage unit pattern surrounded by the first plate layer 250, the dielectric layer 251 and the second plate layer 252 is in an H-shaped cylindrical structure, including a perfect circular cylindrical structure or an elliptical cylindrical structure, and it can also be understood that the capacitor storage unit includes an upper capacitor storage unit and a lower capacitor storage unit, and the two capacitor storage units share the second plate layer 252 in the gap 233.

As an example, the first and second pole plate layers 250 and 252 may be formed by ALD, and TiN may be used as a material.

As an example, the dielectric layer 251 may be formed using an ALD method. The dielectric layer 251 may be a single layer made of an insulating material, or may be a stacked structure made of an insulating material and a high-K dielectric material, for example, in this embodiment, the dielectric layer 251 is sequentially formed by a high-K layer, an insulating layer, and a stacked structure of the high-K layer from inside to outside, and the high-K layer is made of ZrO₂Or HfO₂The material of the insulating layer is Al₂O₃Or SiO₂。

As an example, the step of removing the support layer 232 is further included after the first pole plate layer 250, the dielectric layer 251, and the second pole plate layer 252 are formed.

As shown in fig. 1 and 18, next, in step S8, the first drain region 213b, the first channel region 212 and the first source region 211 are patterned to have a remaining thickness, so as to form a fourth stacked structure 260.

As shown in fig. 17 and 18, the fourth stacked structure 260 may be formed by using a dry etching process, for example. Specifically, as shown in fig. 17, a second insulating layer 301 is formed around the third stacked structure 240, and the material of the second insulating layer 301 is TEOS, but is not limited thereto, and may be adaptively changed as needed, and is not limited thereto; as shown in fig. 18, a fourth stacked structure 260 is then formed by lithographically etching the first drain region 213b, the first channel region 212, and the first source region 211 with a remaining thickness based on the second insulating layer 301.

As shown in fig. 1 and fig. 22, step S9 is performed to sequentially form a first gate dielectric layer 271 and a first gate metal layer 272 around the first channel region 212 in the fourth stacked structure 260, so as to obtain a first logic cell gate-all-around structure 270.

As an example, the first gate dielectric layer 271 includes one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer, and a zirconium oxide layer, and the first gate metal layer 272 includes one or a combination of a TiN layer, a Ti layer, a TaN layer, and a Ta layer. In this embodiment, the first gate dielectric layer 271 is a stacked layer of a silicon oxide layer and a hafnium oxide layer, and the first gate metal layer 272 is a TiN layer.

As shown in fig. 19 to 22, as an example, a method of forming the first logic cell gate all around structure 270 includes: as shown in fig. 19, a third insulating layer 302 is first deposited on the surface of the substrate 100, the material of the third insulating layer 302 is TEOS, but is not limited thereto, and may be adaptively changed according to the needs, and is not limited herein; as shown in fig. 20, the first gate dielectric layer 271 is then deposited on the sidewall ALD of the fourth stacked structure 260; as shown in fig. 21, the first gate metal layer 272 is then PVD deposited around the periphery of the first channel region 212; as shown in fig. 22, the first gate metal layer 272 is finally patterned by dry etching for subsequent electrical extraction. It should be noted that the first gate dielectric layer 271 may also be formed in a region outside the first channel region 212, but the first gate dielectric layer 271 may surround the first channel region 212.

As shown in fig. 1 and 25, step S10 is performed to remove the first plate layer 250, the dielectric layer 251, and the second plate layer 252 around the second source region 223 and the second channel region 222 in the fourth stacked-layer structure 260, and the remaining first plate layer 250, the dielectric layer 251, and the second plate layer 252 form a capacitor storage unit with an H-shaped cylindrical structure.

As shown in fig. 23 to 25, as an example, the first pole plate layer 250, the dielectric layer 251, and the second pole plate layer 252 around the second source region 223 and the second channel region 222 may be removed by a dry etching process. Specifically, as shown in fig. 23, a fourth insulating layer 303 is formed before the fourth stacked structure 260 is formed around, and a material of the fourth insulating layer 303 is TEOS, but the present invention is not limited thereto, and may also be adaptively changed as needed, and is not limited thereto; as shown in fig. 24 and 25, the first pole plate layer 250, the dielectric layer 251, and the second pole plate layer 252 around the second source region 223 and the second channel region 222 are then lithographically etched based on the fourth insulating layer 303.

As shown in fig. 1 and fig. 26, step S11 is performed to sequentially form a second gate dielectric layer 281 and a second gate metal layer 282 around the second channel region 222 in the fourth stacked structure 260, so as to obtain a second logic cell gate-all-around structure 280.

As an example, the second gate dielectric layer 281 includes one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer, and a zirconium oxide layer, and the second gate metal layer 282 includes one or a combination of a TiN layer, a Ti layer, a TaN layer, and a Ta layer. In this embodiment, the first gate dielectric layer 281 is a stacked layer of a silicon oxide layer and a hafnium oxide layer, and the first gate metal layer 282 is a TiN layer. It should be noted that the second gate dielectric layer 281 may also be formed in a region outside the second channel region 222, but it is sufficient that the second gate dielectric layer 281 surrounds the second channel region 222.

As shown in fig. 1 and fig. 30 to 33, step S12 is finally performed to form a metal connection 290, where the metal connection 290 is electrically connected to the first gate metal layer 272, the second gate metal layer 282, the first source region 211, and the second source region 223.

As shown in fig. 27 to 33, as an example, a specific method of forming the metal connection part 290 includes:

as shown in fig. 27, a fifth insulating layer 304 is first deposited around the second logic cell gate-all-around structure 280, and the material of the fourth insulating layer 303 is TEOS, but the invention is not limited thereto, and can be adapted as required, and is not limited thereto; as shown in fig. 28, the third insulating layer 302, the fourth insulating layer 303 and the fifth insulating layer 304 are etched to form a metal connection hole 293, wherein the metal connection hole 293 is respectively connected to the first gate metal layer 272, the second gate metal layer 282, the first source region 211 and the second source region 223; as shown in fig. 29, an ohmic contact layer 305 is formed on the first source region 211 and the second source region 223, the ohmic contact layer 305 preferably uses a metal silicide, so that the metal silicide serves as an ohmic contact between the metal connection 290 and a silicon material to reduce resistance and improve electrical performance of the device, and the specific type of the metal silicide is not limited herein; as shown in fig. 30, a diffusion barrier 291 is deposited on the inner wall of the metal connection hole 293 by ALD, wherein the diffusion barrier 291 may be a Ti/TiN diffusion barrier, but the kind and the forming method of the diffusion barrier 291 are not limited thereto; as shown in fig. 30, the metal connection hole 293 is filled with a metal layer 292 by MOCVD.

Further, to facilitate understanding of the structure of the vertical memory formed in the present embodiment, fig. 33 is a schematic side view of fig. 30, and fig. 31 and 32 are schematic cross-sectional views of the vertical memory formed, respectively, wherein fig. 31 is a schematic cross-sectional view taken along CC in fig. 30, and fig. 32 is a schematic cross-sectional view taken along DD in fig. 30.

As an example, the first gate metal layer 272 and the second gate metal layer 282 have an included angle θ, and the included angle θ is in a range of 30 ° ≦ θ ≦ 180 °.

Specifically, referring to fig. 30 to 33, in this embodiment, the included angle θ between the first gate metal layer 272 and the second gate metal layer 282 is preferably 90 °, but is not limited thereto, and the value of the included angle θ may also include 20 °, 50 °, 80 °, 110 °, 140 °, 180 °, and the like, which may be selected as needed, and is not limited herein.

Example two

This embodiment provides a vertical memory with an H-shaped capacitor structure, which can be prepared by the method of the first embodiment, but is not limited thereto, as long as the method of the first embodiment can be implemented. For the beneficial effects of the vertical memory of this embodiment, please refer to embodiment one, which is not described herein again. It should be noted that only 1 cell structure of 2T1C is illustrated in this embodiment, and those skilled in the art will understand that the vertical memory may include a plurality of stacked cell structures of 2T 1C.

As shown in fig. 30 to 33, the vertical type memory includes:

a substrate 100;

a first logic cell stacked structure 210 on the substrate 100, including a first source region 211, a first channel region 212, and a first drain region 213 stacked in sequence from bottom to top;

a second logic cell stacked structure 220 on the first logic cell stacked structure 210, including a second drain region 221, a second channel region 222, and a second source region 223 stacked in sequence from bottom to top;

a capacitor storage unit, including a first plate layer 250, a dielectric layer 251 and a second plate layer 252, wherein the first plate layer 250 is respectively contacted with the first drain region 213 and the second drain region 221, the second plate layer 252 is located at the periphery of the first plate layer 250, and a part of the first plate layer 250, a part of the second plate layer 252 and a part of the dielectric layer 251 are filled between the first drain region 213 and the second drain region 221, which is a capacitor storage unit with an H-shaped cylindrical structure;

a first logic cell gate-all-around structure 270 including a first gate dielectric layer 271 surrounding the periphery of the first channel region 212 and a first gate metal layer 272;

a second logic cell gate all around structure 280 including a second gate dielectric layer 281 and a second gate metal layer 282 surrounding the second channel region 222;

a metal connection 290 electrically connected to the first gate metal layer 272, the second gate metal layer 282, the first source region 211, and the second source region 223.

As an example, the substrate 100 includes one of a SOI substrate, a silicon substrate, a sapphire substrate, and a silicon carbide substrate.

Specifically, in the embodiment, the substrate 100 is a SOI substrate, that is, the substrate includes a bottom layer silicon 101, a buried oxide layer 102 and a top layer silicon 103, but the selection of the substrate 100 is not limited thereto, and may be specifically selected according to needs, for example, the substrate 100 may also be a silicon substrate, a sapphire substrate, a silicon carbide substrate, and the like, and is not limited herein.

As an example, the first logic cell stack structure 210 may include one or a combination of an NNN type logic cell stack structure, a PPP type logic cell stack structure, an NPN type logic cell stack structure, and a PNP type logic cell stack structure.

Specifically, the first logic cell stacked structure 210 includes a first source region 211, a first channel region 212, and a first drain region 213 stacked in sequence from bottom to top. In this embodiment, the first logic cell stacked structure 210 is an N-type logic cell, that is, an NPN-type logic cell stacked structure, and in the first logic cell stacked structure 210, the first source region 211 and the first drain region 213 are both made of SiC, the first channel region 212 is made of Si, and doping of the first logic cell stacked structure 210 may be performed during an EPI growth process. Of course, according to the requirement, the first logic cell stacked structure 210 may also adopt an N-type logic cell having an NNN-type logic cell stacked structure, or the first logic cell stacked structure 210 may also be designed as a P-type logic cell, such as a PNP-type logic cell stacked structure or a PPP-type logic cell stacked structure, and the selection of the material and the type of the first logic cell stacked structure 210 is not limited thereto, and may be specifically selected according to the requirement, for example, the material of the first source region 211 and the first drain region 213 is Si, and the material of the first channel region 212 is Ge, which is not limited herein.

As an example, the second logic cell stack structure 220 includes one of an NNN type logic cell stack structure, a PPP type logic cell stack structure, an NPN type logic cell stack structure, and a PNP type logic cell stack structure.

Specifically, the second logic cell stacked structure 220 includes a second drain region 221, a second channel region 222, and a second source region 223 stacked in sequence from bottom to top. In this embodiment, the second logic cell stacked structure 220 is an N-type logic cell, that is, an NPN-type logic cell stacked structure identical to the first logic cell stacked structure 210, and in the second logic cell stacked structure 220, the second drain region 221 and the second source region 223 are both made of SiC, the second channel region 222 is made of Si, and doping of the second logic cell stacked structure 220 may be performed during an EPI growth process. Of course, according to the requirement, the second logic cell stacked structure 220 may also adopt an N-type logic cell having an NNN-type logic cell stacked structure, or the second logic cell stacked structure 220 may also be designed as a P-type logic cell, such as a PNP-type logic cell stacked structure or a PPP-type logic cell stacked structure, and the selection of the material and the type of the second logic cell stacked structure 220 is not limited thereto, and may be specifically selected according to the requirement, for example, the material of the second drain region 221 and the second source region 223 is Si, and the material of the second channel region 222 is Ge, which is not limited herein.

For example, the dielectric layer 251 may be a single layer made of an insulating material, or may be a stacked structure made of an insulating material and a high-K dielectric material, for example, in this embodiment, the dielectric layer 251 is a stacked structure of a high-K layer, an insulating layer and the high-K layer from inside to outside in sequence, and the material of the high-K layer is ZrO₂Or HfO₂The material of the insulating layer is Al₂O₃Or SiO₂。

As an example, the first and second pole plate layers 250 and 252 may be selected to be TiN layers.

As an example, the first gate dielectric layer 271 includes one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer, and a zirconium oxide layer, and the first gate metal layer 272 includes one or a combination of a TiN layer, a Ti layer, a TaN layer, and a Ta layer. In this embodiment, the first gate dielectric layer 271 is a stacked layer of a silicon oxide layer and a hafnium oxide layer, and the first gate metal layer 272 is a TiN layer.

As an example, the second gate dielectric layer 281 includes one or a combination of a silicon oxide layer, an aluminum oxide layer, a hafnium oxide layer, and a zirconium oxide layer, and the second gate metal layer 282 includes one or a combination of a TiN layer, a Ti layer, a TaN layer, and a Ta layer. In this embodiment, the first gate dielectric layer 281 is a stacked layer of a silicon oxide layer and a hafnium oxide layer, and the first gate metal layer 282 is a TiN layer.

As an example, an ohmic contact layer 305 is formed at the bottom of the metal connection 290 on the first source region 211 and the second source region 223, and the ohmic contact layer 305 is preferably made of a metal silicide, so that the metal silicide is used as an ohmic contact between the metal connection 290 and a silicon material to reduce resistance and improve electrical performance of the device, and the specific type of the metal silicide is not limited herein.

As an example, the metal connection 290 includes a diffusion barrier 291 and a metal layer 292.

Specifically, the diffusion barrier 291 may include, but is not limited to, a Ti/TiN diffusion barrier, and the diffusion of the metal layer 292 may be prevented by the diffusion barrier 291 to improve the electrical performance of the device.

As an example, the first gate metal layer 272 and the second gate metal layer 282 have an included angle θ, and the included angle θ is in a range of 30 ° ≦ θ ≦ 180 °.

Specifically, referring to fig. 30 to 33, in this embodiment, the included angle θ between the first gate metal layer 272 and the second gate metal layer 282 is preferably 90 °, but is not limited thereto, and the value of the included angle θ may also include 20 °, 50 °, 80 °, 110 °, 140 °, 180 °, and the like, which may be selected as needed, and is not limited herein.

In summary, the present invention provides a vertical memory with an H-shaped capacitor structure and a method for manufacturing the same, wherein capacitor storage units are formed at the peripheries of the drain regions of the first logic unit and the second logic unit, and the capacitor storage units at the peripheries of the drain regions of the first logic unit and the second logic unit are vertically combined to make the entire capacitor storage unit have an H-shaped cylindrical structure, thereby effectively increasing the area of the capacitor, improving the charge storage capability of the capacitor, and effectively improving the reading accuracy and the charge storage time of the memory. The first logic unit and the second logic unit can independently or jointly store or read data to or from the capacitor storage structure. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.