阅读说明：本技术 一种半导体结构及其制作方法和半导体存储器 (Semiconductor structure, manufacturing method thereof and semiconductor memory ) 是由 邹兵 徐政业 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种半导体结构及其制作方法和半导体存储器。该半导体结构的制作方法包括：提供衬底并对所述衬底进行离子注入,形成有源区；在所述衬底表面形成栅极沟槽；测量所述栅极沟槽的深度；如果所述栅极沟槽的深度满足预设条件时,则根据所述栅极沟槽的深度对所述衬底进行离子注入补偿,在所述栅极沟槽一侧的所述有源区内形成离子补偿区域。该半导体结构的制作方法能够避免由栅极沟槽的深度变异造成的半导体结构性能劣化,改善半导体存储器的性能。(The invention discloses a semiconductor structure, a manufacturing method thereof and a semiconductor memory. The manufacturing method of the semiconductor structure comprises the following steps: providing a substrate and carrying out ion implantation on the substrate to form an active region; forming a grid groove on the surface of the substrate; measuring the depth of the gate trench; and if the depth of the grid groove meets a preset condition, carrying out ion implantation compensation on the substrate according to the depth of the grid groove, and forming an ion compensation area in the active area on one side of the grid groove. The manufacturing method of the semiconductor structure can avoid the performance degradation of the semiconductor structure caused by the depth variation of the grid groove and improve the performance of the semiconductor memory.)

1. A method for fabricating a semiconductor structure, comprising:

providing a substrate and carrying out ion implantation on the substrate to form an active region;

forming a grid groove on the surface of the substrate;

measuring the depth of the gate trench;

and if the depth of the grid groove meets a preset condition, carrying out ion implantation compensation on the substrate according to the depth of the grid groove, and forming an ion compensation area in the active area on one side of the grid groove.

2. The method of claim 1, wherein forming an ion compensation region in the active region on one side of the gate trench comprises:

forming a bit line contact hole in the active region on one side of the gate trench;

and performing ion implantation compensation on the substrate through the bit line contact hole to form the ion compensation region.

3. The method of claim 1, wherein the compensating the substrate for the ion implantation according to the depth of the gate trench comprises:

determining the implantation depth of compensation ions according to the depth of the grid groove;

determining the implantation energy of the compensating ions according to the implantation depth of the compensating ions;

and according to the implantation energy of the compensation ions, performing ion implantation compensation on the substrate to form the ion compensation area.

4. The method according to claim 1, wherein the predetermined condition is that the depth of the gate trench is less than a target depth, and an absolute value of a difference between the depth of the gate trench and the target depth is greater than a threshold standard deviation;

the threshold standard deviation is determined according to the statistical result of the depths of the plurality of gate trenches which are manufactured by taking the target depth as a process parameter.

5. The method of claim 2, wherein the forming a gate trench in the substrate surface comprises:

forming a shallow trench isolation structure on the surface of the substrate, and dividing the active region into a plurality of blocks;

and forming the grid groove on the surface of the substrate, wherein the depth of the grid groove is less than that of the shallow channel isolation structure.

6. The method of claim 5, further comprising, after measuring the depth of the gate trench:

sequentially forming a gate oxide layer and a diffusion barrier layer on the surface of the gate trench;

filling word lines in the grid grooves;

forming a protective layer on the surfaces of the word line and the substrate;

the forming of the bit line contact hole in the active region at one side of the gate trench includes:

etching the protective layer to form the bit line contact hole; the bit line contact hole penetrates through the protective layer and exposes out of the substrate; the bit line contact hole is positioned between two adjacent grid grooves in the same active region.

7. A semiconductor structure, manufactured by the method of manufacturing a semiconductor structure according to any one of claims 1 to 6, comprising:

the device comprises a substrate, a grid groove and an ion compensation area;

an active region is located in the substrate;

the ion compensation region is located in the active region on one side of the grid groove, and the depth of the active region meets a preset condition.

8. The semiconductor structure of claim 7, further comprising a bit line contact hole, a vertical projection of the bit line contact hole on the substrate at least partially overlapping a vertical projection of the ion compensation region on the substrate.

9. The semiconductor structure of claim 8, further comprising shallow trench isolation structures on the surface of the substrate and separating the active regions into blocks, wherein the depth of the gate trenches is less than the depth of the shallow trench isolation structures;

the semiconductor structure further includes:

the gate oxide layer and the diffusion barrier layer are positioned on the surface of the gate groove;

word lines located within the gate trenches;

and the bit line contact hole penetrates through the protective layer and exposes out of the substrate, and is positioned between two adjacent grid grooves in the same active region.

10. A semiconductor memory comprising the semiconductor structure of any one of claims 7-9.

Technical Field

The embodiment of the invention relates to the technical field of semiconductors, in particular to a semiconductor structure, a manufacturing method thereof and a semiconductor memory.

Background

The embedded word line is embedded in the semiconductor substrate, so that parasitic capacitance between the word line and the bit line can be significantly reduced, the reliability of voltage reading operation of the semiconductor device is greatly improved, and a new choice is provided for increasing the integration density of the semiconductor device.

In the prior art, before the gate trench of the embedded transistor is fabricated, the ion implantation is completed, that is, the parameters of the implanted ions are determined, and there is a possibility that the depth of the gate trench varies in the subsequent process, so that the threshold voltage varies, which may cause the performance of the embedded transistor to deteriorate, and further cause the yield or reliability of the semiconductor memory to deteriorate.

Disclosure of Invention

The invention provides a semiconductor structure, a manufacturing method thereof and a semiconductor memory, which are used for avoiding the performance degradation of the semiconductor structure caused by the depth variation of a grid groove and improving the performance of the semiconductor memory.

In a first aspect, an embodiment of the present invention provides a method for manufacturing a semiconductor structure, including:

providing a substrate and carrying out ion implantation on the substrate to form an active region;

forming a grid groove on the surface of the substrate;

measuring the depth of the gate trench;

and if the depth of the grid groove meets a preset condition, forming an ion compensation area in the active area on one side of the grid groove.

Optionally, forming an ion compensation region in the active region on one side of the gate trench includes:

forming a bit line contact hole in the active region on one side of the gate trench;

and performing ion implantation compensation on the substrate through the bit line contact hole to form the ion compensation region.

Optionally, the performing ion implantation compensation on the substrate according to the depth of the gate trench includes:

determining the implantation depth of compensation ions according to the depth of the grid groove;

determining the implantation energy of the compensating ions according to the implantation depth of the compensating ions;

and according to the implantation energy of the compensation ions, performing ion implantation compensation on the substrate to form the ion compensation area.

Optionally, the preset condition is that the depth of the gate trench is smaller than a target depth, and an absolute value of a difference between the depth of the gate trench and the target depth is greater than a threshold standard deviation;

the threshold standard deviation is determined according to the statistical result of the depths of the plurality of gate trenches which are manufactured by taking the target depth as a process parameter.

Optionally, the forming a gate trench on the surface of the substrate includes:

forming a shallow trench isolation structure on the surface of the substrate, and dividing the active region into a plurality of blocks;

and forming the grid groove on the surface of the substrate, wherein the depth of the grid groove is less than that of the shallow channel isolation structure.

Optionally, after measuring the depth of the gate trench, the method further includes:

sequentially forming a gate oxide layer and a diffusion barrier layer on the surface of the gate trench;

filling word lines in the grid grooves;

forming a protective layer on the surfaces of the word line and the substrate;

the forming of the bit line contact hole in the active region at one side of the gate trench includes:

etching the protective layer to form the bit line contact hole; the bit line contact hole penetrates through the protective layer and exposes out of the substrate; the bit line contact hole is positioned between two adjacent grid grooves in the same active region.

In a second aspect, an embodiment of the present invention provides a semiconductor structure, which is manufactured by using any one of the methods for manufacturing a semiconductor provided in the first aspect, and includes: the device comprises a substrate, a grid groove and an ion compensation area;

an active region is formed in the substrate;

the ion compensation region is located in the active region on one side of the grid groove, and the depth of the active region meets a preset condition.

Optionally, the semiconductor structure further comprises a bit line contact hole, and a vertical projection of the bit line contact hole on the substrate at least partially overlaps a vertical projection of the ion compensation region on the substrate.

Optionally, the semiconductor structure further includes a shallow trench isolation structure, the shallow trench isolation structure is located on the surface of the substrate and separates the active region into a plurality of blocks, and the depth of the gate trench is smaller than that of the shallow trench isolation structure;

the semiconductor structure further includes:

the gate oxide layer and the diffusion barrier layer are positioned on the surface of the gate groove;

word lines located within the gate trenches;

and the bit line contact hole penetrates through the protective layer and exposes out of the substrate, and is positioned between two adjacent grid grooves in the same active region.

In a third aspect, embodiments of the present invention provide a semiconductor memory device, including any one of the semiconductor structures provided in the second aspect.

According to the technical scheme provided by the embodiment of the invention, the depth of the grid groove is measured, whether the depth of the grid groove meets the preset condition is judged, if the depth of the grid groove meets the preset condition, the distance between the grid groove and the channel adjusting doped region is relatively long, the influence of the channel adjusting doped region on threshold voltage adjustment is relatively small, the blocking effect on the conduction of the source and drain regions at two sides of the grid groove is relatively weak, namely the source and drain regions at two sides of the grid groove are relatively easy to conduct, namely the threshold voltage of the semiconductor structure is relatively small; by performing acceptor ion implantation compensation on the substrate according to the depth of the grid groove, an ion compensation region is formed in the active region on one side of the grid groove, the ion compensation region is closer to the grid groove, and the conduction of source and drain regions on two sides of the grid groove can be effectively blocked to a certain extent, so that the threshold voltage of the semiconductor structure is improved, the reduction of the threshold voltage caused by the over-shallow depth of the grid groove is compensated, the performance degradation of the semiconductor structure caused by the depth variation of the grid groove is avoided, and the performance of the semiconductor memory is improved.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, a brief description is given below of the drawings used in describing the embodiments. It should be clear that the described figures are only views of some of the embodiments of the invention to be described, not all, and that for a person skilled in the art, other figures can be derived from these figures without inventive effort.

Fig. 1 is a schematic flow chart illustrating a method for fabricating a semiconductor structure according to an embodiment of the present invention;

FIGS. 2-5 are schematic views of the manufacturing processes of the steps of the method for manufacturing a semiconductor structure according to the embodiment of the invention;

FIG. 6 is a schematic diagram illustrating a relationship between a depth of a gate trench and a threshold voltage according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating a relationship between a threshold voltage and a yield according to an embodiment of the present invention

FIG. 8 is a flow chart illustrating a method of fabricating a semiconductor structure according to yet another embodiment of the present invention;

FIGS. 9 and 10 are schematic views of the manufacturing processes of the steps of a method for manufacturing an ion compensation region according to an embodiment of the present invention;

fig. 11 is a flowchart illustrating an ion implantation compensation method according to an embodiment of the present invention.

Fig. 12 is a schematic diagram illustrating a relationship between a depth of a gate trench and an ion implantation depth according to an embodiment of the present invention;

fig. 13 is a schematic diagram illustrating a relationship between an ion implantation depth and an ion implantation energy according to an embodiment of the present invention;

FIG. 14 is a flowchart illustrating a method of fabricating a semiconductor structure according to yet another embodiment of the present invention;

FIG. 15 is a graph illustrating statistical results of depths of gate trenches of a plurality of semiconductor structures according to an embodiment of the present invention;

fig. 16 is a flowchart illustrating a method for forming a gate trench according to an embodiment of the present invention;

FIG. 17 is a flowchart illustrating a method of fabricating a semiconductor structure according to yet another embodiment of the present invention;

fig. 18 is a schematic view of a manufacturing process of a word line manufacturing method according to an embodiment of the invention;

fig. 19 is a schematic structural diagram of a semiconductor memory according to an embodiment of the invention.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting of the application. It should be further noted that, for the convenience of description, only some of the structures related to the present application are shown in the drawings, not all of the structures.

Fig. 1 is a schematic flow chart of a method for manufacturing a semiconductor structure according to an embodiment of the present invention, and fig. 2 to 5 are schematic process diagrams of steps of the method for manufacturing a semiconductor structure according to the embodiment of the present invention. As shown in fig. 1, the method specifically comprises the following steps:

s110, providing a substrate and carrying out ion implantation on the substrate to form an active region.

Illustratively, as shown in fig. 2, for example, in the case of an NMOS, N-type ions are implanted into the substrate 110 to form an active region 121 with a certain depth, and acceptor impurities are implanted into the active region 121 to form a channel-adjusting doped region 122, so that the voltage generated by the channel-adjusting doped region 122 controls the density of conductive particles in the active region 121. In other embodiments, the active region 121 may be formed by P-type ions, and the channel-adjusting doped region 122 may be formed by implanting donor impurities. It should be noted that the substrate 110 may be made of, but not limited to, silicon, germanium, silicon germanium, and other commonly used semiconductor substrate materials, and the type of the implanted ions is selected according to actual requirements.

And S120, forming a gate groove on the surface of the substrate.

Specifically, a substrate protection layer 131 is deposited and formed on the surface of the substrate 110, a hard mask layer 132 is deposited and formed on the surface of the substrate protection layer 131, which is away from the substrate 110, a photoresist material is coated on the surface of the hard mask layer 132, which is away from the substrate 110, to form a photoresist layer 133, and a pattern of a gate trench is formed on the photoresist layer 133 by exposure using a mask plate of the gate trench, as shown in fig. 3; the photoresist layer 133, the hard mask layer 132 and the substrate protection layer 131 are used as a mask together, a plurality of gate trenches 140 are formed on the surface of the substrate 110 by etching, the photoresist layer 133 is removed, and source and drain regions are formed on two sides of the gate trenches 140, as shown in fig. 4. The material of the substrate protection layer 131 is selected from one of the group consisting of silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, silicon carbonitride, silicon oxycarbonitride, and boron nitride, and the material of the hard mask layer 133 is selected from one of the group consisting of silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, silicon carbonitride, silicon oxycarbonitride, and boron nitride, for example, the substrate protection layer 131 may be selected from silicon oxide, and the hard mask layer 133 may be selected from silicon nitride.

And S130, measuring the depth of the gate trench.

And S140, if the depth of the grid groove meets a preset condition, performing ion implantation compensation on the substrate according to the depth of the grid groove, and forming an ion compensation area in the active area on one side of the grid groove.

Specifically, as shown in fig. 5, the depth h of the gate trench 140 is measured, and if the depth h of the gate trench 140 satisfies the predetermined condition, it indicates that the depth h of the gate trench 140 is shorter, that is, the gate trench 140 is farther from the channel-adjusting doped region 122. The acceptor impurity in the channel adjustment doping region 122 can control the density of the movable charges in the active region 121, and if the gate trench 140 is far from the channel adjustment doping region 122, the control effect of the channel adjustment doping region 122 on the density of the movable charges near the gate trench 140 can be reduced, and the charges in the source-drain region on one side of the gate trench 140 can more easily pass through the gate trench 140 to reach the source-drain region on the other side, that is, the source-drain regions on both sides of the gate trench 140 are more easily conducted, so that the conduction voltage of the source-drain regions is reduced, that is, the threshold voltage of the semiconductor structure is reduced. The threshold voltage reduction affects the performance of the semiconductor structure, and is analyzed as follows.

For example, fig. 6 is a schematic diagram of a relationship between a depth of a gate trench and a threshold voltage according to an embodiment of the present invention, and fig. 7 is a schematic diagram of a relationship between a threshold voltage and a yield according to an embodiment of the present invention. Referring to fig. 6 and 7, the electrical threshold voltage of the semiconductor structure changes by 10mV for every 1nm change in the depth of the gate trench, and the yield of the semiconductor structure is significantly reduced when the threshold voltage of the semiconductor structure is less than 670mV, so that it is necessary to ensure that the threshold voltage Vth of the semiconductor structure is greater than 670mV to ensure the performance of the semiconductor structure.

In the embodiment of the present invention, the substrate 110 is compensated by ion implantation according to the depth of the gate trench 140, and the ion compensation region 150 is formed in the active region 121 on one side of the gate trench 140, as shown in fig. 5, the ion compensation region 150 has the same function as the channel adjustment doping region 122, and has a control function on the density of the movable charges near the gate trench 140, so that the source and drain regions on both sides of the gate trench 140 are more difficult to be turned on, thereby increasing the on-state voltage of the source and drain regions, i.e., the threshold voltage, compensating for the decrease in the threshold voltage caused by the over-shallow depth of the gate trench 140, avoiding the degradation of the semiconductor structure performance caused by the depth variation of the gate trench 140, and improving the performance of the semiconductor memory.

Optionally, fig. 8 is a schematic flowchart of a method for manufacturing a semiconductor structure according to another embodiment of the present invention. As shown in fig. 8, the specific steps include:

s110, providing a substrate and carrying out ion implantation on the substrate to form an active region.

And S120, forming a gate groove on the surface of the substrate.

And S130, measuring the depth of the gate trench.

S141, if the depth of the grid groove meets a preset condition, forming a bit line contact hole in the active region on one side of the grid groove;

and S142, performing ion implantation compensation on the substrate through the bit line contact hole to form the ion compensation region.

Specifically, fig. 9 and fig. 10 are schematic views of the manufacturing processes of the steps of the method for manufacturing the ion compensation region according to the embodiment of the present invention. When the depth of the gate trench 140 satisfies a predetermined condition, a photoresist layer 134 is formed on the side of the passivation layer 161 away from the substrate 110, and exposure is performed using a mask for bit line contact holes, so as to form a bit line contact hole pattern on the photoresist layer 134, as shown in fig. 9. The photoresist layer 134, the diffusion barrier layer 162, the protection layer 161 and the substrate 110 are used together as a mask, a plurality of bit line contact holes 170 are formed on the surface of the substrate 110 by etching, the photoresist layer 134 is removed, ion implantation compensation is performed on the substrate 110 through the bit line contact holes 170, and the implanted ions are diffused in the substrate 110 to form an ion compensation region 150 with a certain depth, as shown in fig. 10. Since ion implantation needs to be performed on the surface of the substrate 110 to ensure that the implanted ions form the ion compensation region 150 in the active region 121, the surface of the substrate 110 needs to be exposed by etching or other processes to perform the implantation of the compensation ions.

Optionally, fig. 11 is a schematic flowchart of a method for ion implantation compensation according to an embodiment of the present invention. As shown in fig. 11, the specific steps include:

s210, determining the implantation depth of compensation ions according to the depth of the grid groove;

specifically, fig. 12 is a schematic diagram illustrating a relationship between a depth of a gate trench and an ion implantation depth according to an embodiment of the present invention. As shown in fig. 12, the relationship between the measured value of the depth of the gate trench and the ion implantation depth is obtained through a large amount of experimental data, and when the measured value of the depth of the gate trench is H1, the corresponding ion implantation depth is H1.

S220, determining the implantation energy of the compensation ions according to the implantation depth of the compensation ions;

specifically, fig. 13 is a schematic diagram illustrating a relationship between an ion implantation depth and an ion implantation energy according to an embodiment of the present invention. In an actual process, the implantation depth of the ions depends on the implantation energy of the ions, and the relationship between the implantation depth of the ions and the implantation energy of the ions is obtained according to the disclosed data, as shown in fig. 13, when the implantation depth of the ions is H1, the implantation energy of the corresponding ions is E1, so that the implantation energy of the ions can be determined to be E1 according to the depth H1 of the gate trench.

S240, according to the implantation energy of the compensation ions, ion implantation compensation is carried out on the substrate, and the ion compensation area is formed.

Illustratively, the depth of the gate trench is measured as h1, the implantation energy E1 of the compensating ions can be determined, and the implantation energy E1 of the compensating ions is used as a process parameter to perform ion implantation compensation on the substrate, so as to form an ion compensation region in the active region on one side of the gate trench to compensate the threshold voltage.

Optionally, the implantation dose D of the compensation ions may be obtained by obtaining a relationship between a threshold voltage or a yield parameter and an ion implantation dose through a large amount of experimental data, and then performing corresponding calculation according to the threshold voltage to be compensated.

Optionally, fig. 14 is a schematic flowchart of a method for manufacturing a semiconductor structure according to another embodiment of the present invention. As shown in fig. 14, the specific steps include:

s110, providing a substrate and carrying out ion implantation on the substrate to form an active region.

And S120, forming a gate groove on the surface of the substrate.

And S130, measuring the depth of the gate trench.

S143, if the depth of the gate trench meets the condition that the depth of the gate trench is smaller than a target depth, and the absolute difference value between the depth of the gate trench and the target depth is larger than a threshold standard deviation; and performing ion implantation compensation on the substrate according to the depth of the gate trench, and forming an ion compensation region in the active region on one side of the gate trench.

The threshold standard deviation is determined according to the statistical result of the depths of the gate trenches of the plurality of semiconductor structures which are manufactured by taking the target depth as a process parameter.

Specifically, when h2 is used as a process parameter to fabricate the semiconductor structure, the target depth is h2, and due to the influence of process equipment, process environment and the like, the depth h of the gate trench of the fabricated semiconductor structure may be greater than the target depth h2 or less than the target depth h2, and when the depth h of the gate trench is within a certain deviation range of the target depth h2, the performance of the semiconductor structure is not affected. The method comprises the steps of measuring the depth h of a plurality of gate grooves of semiconductor structures with normal performance, and calculating according to the statistical result of the depth h of the gate grooves to obtain a threshold standard deviation. Illustratively, N semiconductor structures which are normally manufactured by taking the target depth h2 as a process parameter are selected, and the depth h 'of the gate trench of the N semiconductor structures with normal performance is measured'_i(i is more than or equal to 1 and less than or equal to N), and calculating the depth h 'of the N grid grooves'_iAverage value h of_avgAnd standard deviation s, the average value h_avgAs the standard mean SH, the standard deviation s is taken as the threshold standard deviation DS_thThat is, when the absolute value of the difference between the depth h of the gate trench of the semiconductor structure and the standard mean value SH is within the threshold standard deviation DS_thWithin the range, it is determined that no abnormality has occurred in the trench depth of the semiconductor structure. It should be noted that, the embodiments of the present invention only illustrate the determination method of the standard mean and the threshold standard deviation, and the present application is not particularly limited.

When the depth h of the gate trench is smaller than the target depth h2, the gate trench is farther from the channel adjustment doping region 122, so that there is a risk of reducing the threshold voltage, and it is necessary to further confirm whether the depth h of the gate trench is small enough to affect the threshold voltage of the semiconductor structure; when the absolute value of the difference between the depth h of the gate trench of the semiconductor structure and the standard average value SH is larger than the threshold standard deviation DS_thSince the trench depth of the semiconductor structure is abnormal, compensation needs to be performed by implanting compensation ions.

For example, fig. 15 is a diagram illustrating statistical results of depths of gate trenches of a plurality of semiconductor structures according to an embodiment of the present invention. As shown in fig. 15, a plurality of semiconductor structures are selected, the depths of the gate trenches of the semiconductor structures are measured, and the obtained statistical results are calculated to obtain that the average value of the depths of the gate trenches of the semiconductor structures is 137nm, the standard deviation of the threshold value is 1.4nm, the threshold voltage of the semiconductor structure has an error of 3% within a range of one time of the standard deviation of the threshold value, and the threshold voltage of the semiconductor structure has an error of at least 10% within a range of three times of the standard deviation of the threshold value. By compensating the threshold voltage through the method, the error of the threshold voltage of the finally obtained semiconductor structure is less than 3%.

Optionally, fig. 16 is a schematic flowchart of a method for manufacturing a gate trench according to an embodiment of the present invention. As shown in fig. 16, the specific steps include:

and S121, forming a shallow trench isolation structure on the surface of the substrate, and dividing the active region into a plurality of blocks.

And S122, forming the gate trench on the surface of the substrate, wherein the depth of the gate trench is smaller than that of the shallow trench isolation structure.

Specifically, as shown in fig. 5, gate trenches 140 of shallow trench isolation structures 180 are formed on the surface of the substrate 110, the active regions 121 are separated by the shallow trench isolation structures 180, and the depth Z of the shallow trench isolation structures 180 is greater than the depth h of the gate trenches 140, so as to separate the semiconductor structures by the shallow trench isolation structures 180, and ensure that each semiconductor structure can operate independently without being affected by voltage and current changes of adjacent semiconductor structures.

Optionally, fig. 17 is a schematic flowchart of a method for manufacturing a semiconductor structure according to another embodiment of the present invention. As shown in fig. 17, the specific steps include:

after the measuring the depth of the gate trench, the method further includes:

s310, providing a substrate and carrying out ion implantation on the substrate to form an active region.

And S320, forming a gate groove on the surface of the substrate.

S330, measuring the depth of the gate groove.

S340, sequentially forming a gate oxide layer and a diffusion barrier layer on the surface of the gate trench;

s350, filling word lines in the grid groove;

s360, forming a protective layer on the surfaces of the word lines and the substrate;

s370, etching the protective layer to form the bit line contact hole; the bit line contact hole penetrates through the protective layer and exposes out of the substrate; the bit line contact hole is positioned between two adjacent grid grooves in the same active region;

for example, fig. 18 is a schematic view of a manufacturing process of a method for manufacturing a word line according to an embodiment of the present invention. A gate oxide layer 163 can be formed on the surface of the gate trench by thermal oxidation or other deposition methods, and the material of the gate oxide layer 163 is generally silicon oxide; a diffusion barrier layer 162 is formed on the side of the gate oxide layer 163 facing away from the substrate 110 and on the surface of the shallow trench isolation structure 180, and the diffusion barrier layer 162 is made of a material including, but not limited to, titanium nitride or tantalum nitride for reducing or preventing diffusion between the word line 190 and the substrate 110. A metal layer 190 is deposited on the surface of the diffusion barrier layer 162, and the metal layer 190 may be selected from tungsten or other commonly used word line materials, as shown in fig. 18.

Back-etching the metal layer 190 to make the metal layer 190 lower than the upper surface of the substrate 110, i.e. forming the word line 190 in the gate trench 140 and the shallow trench isolation structure 180, and removing the diffusion barrier layer 162 outside the gate trench 140 and the shallow trench isolation structure 180 in the back-etching process; a protective layer 161 is then formed on the surface of the word line 190, and the protective layer 161 is used to protect the word line 190, preferably a silicon nitride material, as shown in fig. 9.

Forming a bit line contact hole 170 on the surface of the protection layer 161 by etching; the bit line contact holes 170 penetrate the protection layer 161 and expose the substrate 110, so that the compensation ions can be implanted into the substrate 110 through the bit line contact holes 170, thereby forming the ion compensation regions 150 by diffusion in the active regions 121, as shown in fig. 10.

And S380, if the depth of the grid groove meets a preset condition, carrying out ion implantation compensation on the substrate according to the depth of the grid groove, and forming an ion compensation area in the active area on one side of the grid groove.

Based on the same inventive concept, the embodiment of the invention also provides a semiconductor structure, which is manufactured by the manufacturing method of the semiconductor structure provided by any embodiment of the invention, and has corresponding beneficial effects of the method.

An embodiment of the present invention provides a semiconductor structure, which is shown in fig. 5, and the semiconductor structure 100 includes: substrate 110, gate trench 140, and ion compensation region 150. The active region 121 is located in the substrate 110; the ion compensation region 150 is located in the active region 121 at a side of the gate trench 140 where the depth satisfies a predetermined condition.

In the embodiment of the invention, the substrate 110 is subjected to ion implantation compensation according to the depth of the gate trench 140, the ion compensation region 150 is formed in the active region 121 on one side of the gate trench 140, and the ion compensation region 150 plays a role in controlling the density of movable charges in the source and drain regions, so that the source and drain regions on two sides of the gate trench 140 are more difficult to be conducted, the threshold voltage is improved, the reduction of the threshold voltage caused by the over-shallow depth of the gate trench 140 is compensated, the degradation of the performance of a semiconductor structure caused by the depth variation of the gate trench 140 is avoided, and the performance of a semiconductor memory is improved.

Optionally, another semiconductor structure is provided in the embodiment of the present invention, and the structure of the semiconductor structure 100 is as shown in fig. 10, where a vertical projection of the bit line contact hole 170 on the substrate 110 at least partially overlaps a vertical projection of the ion compensation region 150 on the substrate 110. Since ion implantation needs to be performed on the substrate 110 to ensure that the implanted ions form the ion compensation region on the substrate 110, the substrate 110 needs to be exposed by etching or other processes to perform the implantation of the compensation ions.

Optionally, with reference to fig. 5 and fig. 10, the semiconductor structure 100 further includes shallow trench isolation structures 180, a gate trench 140 is disposed between two adjacent shallow trench isolation structures 180, and a depth h of the gate trench 140 is smaller than a depth Z of the shallow trench isolation structures 180; the semiconductor structure 100 further comprises a gate oxide layer 163 and a diffusion barrier layer 162 on the surface of the gate trench 140 and the shallow trench isolation structure 180; word lines 190 in the gate trenches 140 and the shallow trench isolation structures 180; the passivation layer 161 is disposed on the surface of the word line 190, and the bit line contact hole 170 penetrates the passivation layer 161 and exposes the substrate 110.

Based on the same inventive concept, embodiments of the present invention further provide a semiconductor memory, including the semiconductor structure provided by any embodiment of the present invention, and having corresponding functions and beneficial effects of the semiconductor structure.

Fig. 19 is a schematic structural diagram of a semiconductor memory according to an embodiment of the invention. As shown in fig. 19, the semiconductor memory 200 includes a plurality of semiconductor structures 100.

The semiconductor memory 200 provided by the embodiment of the invention has the advantages of the semiconductor structure 100 in the above embodiments, and the details are not repeated herein.

The foregoing is considered as illustrative of the preferred embodiments of the invention and technical principles employed. The present invention is not limited to the specific embodiments herein, and it will be apparent to those skilled in the art that various changes, rearrangements, and substitutions can be made without departing from the scope of the invention. Therefore, although the present invention has been described in more detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the claims.