阅读说明：本技术 半导体器件的制备方法 (Method for manufacturing semiconductor device ) 是由 不公告发明人 于 2018-09-11 设计创作，主要内容包括：本申请涉及一种半导体器件的制备方法,其包括：提供待刻蚀目标；在待刻蚀目标的表面依次形成第一掩膜层、第一抗反射层及第二掩膜层；在包含氮气的反应气体中,将第二抗反射层形成在第二掩膜层的表面；在第二抗反射层的表面形成光刻胶掩膜图案；使用光刻胶掩膜图案作为蚀刻掩膜,以在第一抗反射层上形成第一中间掩膜图案；在第一抗反射层及第一中间掩膜图案上形成介质层；将第一抗反射层上除侧墙之外的其他部分蚀刻,以形成第二中间掩膜图案；使用第二中间掩膜图案作为蚀刻掩膜,蚀刻第一抗反射层及第一掩膜层,以在待刻蚀目标上形成目标图案。这样设计可缓解光刻胶与第二抗反射层发生低膜存留现象的情况,保证了半导体器件制备过程中的优良率。(The application relates to a preparation method of a semiconductor device, which comprises the following steps: providing a target to be etched; sequentially forming a first mask layer, a first anti-reflection layer and a second mask layer on the surface of a target to be etched; forming a second antireflective layer on a surface of the second mask layer in a reaction gas containing nitrogen; forming a photoresist mask pattern on the surface of the second anti-reflection layer; forming a first intermediate mask pattern on the first anti-reflection layer using the photoresist mask pattern as an etching mask; forming a dielectric layer on the first anti-reflection layer and the first intermediate mask pattern; etching the other parts of the first anti-reflection layer except the side wall to form a second intermediate mask pattern; and etching the first anti-reflection layer and the first mask layer by using the second intermediate mask pattern as an etching mask so as to form a target pattern on the target to be etched. The design can relieve the condition that the photoresist and the second anti-reflection layer have low film retention, and ensure the excellent rate in the preparation process of the semiconductor device.)

1. A method of manufacturing a semiconductor device, comprising:

providing a target to be etched;

forming a first mask layer on the surface of the target to be etched;

forming a first anti-reflection layer on the surface of the first mask layer;

forming a second mask layer on the surface of the first anti-reflection layer;

forming a second anti-reflection layer on a surface of the second mask layer in a reaction gas containing nitrogen;

forming a photoresist mask pattern on the surface of the second anti-reflection layer;

etching the second anti-reflection layer and the second mask layer by using the photoresist mask pattern as an etching mask so as to form a first intermediate mask pattern on the first anti-reflection layer, wherein the first intermediate mask pattern comprises a second mask sublayer and a second anti-reflection sublayer;

forming a dielectric layer on the first anti-reflection layer and the first intermediate mask pattern, wherein the dielectric layer comprises a side wall formed at the side part of the first intermediate mask pattern;

etching the other parts of the first anti-reflection layer except the side wall to form a second intermediate mask pattern;

and etching the first anti-reflection layer and the first mask layer by using the second intermediate mask pattern as an etching mask so as to form a target pattern on the target to be etched.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the second antireflection layer comprises silicon oxynitride.

3. The method of manufacturing a semiconductor device according to claim 2, wherein the second anti-reflective layer is deposited at a rate of 0.2nm/sec to 1.0nm/sec, at a temperature of 250 ℃ to 500 ℃, under a pressure of 3to 10tor, and under a radio frequency power of 100W to 300W in the process of forming the second anti-reflective layer on the surface of the second mask layer.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the reaction gas further comprises monosilane gas, nitrous oxide gas, and helium gas.

5. The method for manufacturing a semiconductor device according to claim 4, wherein a flow rate of the monosilane gas is 200sccm to 600sccm, a flow rate of the nitrous oxide gas is 300sccm to 1000sccm, a flow rate of the helium gas is 8000sccm to 12000sccm, and a flow rate of the nitrogen gas is 2000sccm to 5000sccm in forming the second antireflective layer on the surface of the second mask layer.

6. The method according to claim 1, wherein the reaction gas further comprises one or more of nitric oxide gas, nitrogen dioxide, and dinitrogen tetroxide.

7. The method for manufacturing a semiconductor device according to claim 1, wherein the target to be etched comprises one or more of silicon dioxide, polysilicon, and silicon nitride.

8. The method for manufacturing a semiconductor device according to claim 1, wherein the first mask layer and the second mask layer each include amorphous carbon, and wherein the first antireflection layer includes silicon oxynitride.

9. The method for manufacturing a semiconductor device according to claim 1, wherein the forming of the photoresist mask pattern on the surface of the second anti-reflection layer comprises:

forming photoresist on the surface of the second anti-reflection layer;

and carrying out photoetching process on the photoresist by adopting a photomask plate with a pattern.

10. The method for manufacturing a semiconductor device according to claim 1, wherein the etching the first anti-reflection layer except the side walls to form a second intermediate mask pattern comprises:

performing an anisotropic etching process on the dielectric layer to etch the other parts except the first intermediate mask pattern and the side walls;

etching the first intermediate mask pattern to form the second intermediate mask pattern.

Technical Field

The application relates to the technical field of semiconductor manufacturing, in particular to a preparation method of a semiconductor device.

Background

As the size of semiconductor devices continues to shrink, the pattern transfer requirements during photolithography are also more precise. The increasing demand for resolution of photoresist as an important tool for assisting pattern transfer in the photolithography process, accompanied by the reduction in photolithography size, has led to the shift of photolithography to deep ultraviolet short wavelengths, such as: from 248nm to 193 nm. However, in the photolithography and development process, when the anti-reflection layer at the bottom of the photoresist is silicon oxynitride (SiON), the photoresist and the surface layer of SiON may have a phenomenon of low film retention, which may further cause a variation in the line width after etching, thereby reducing the yield in the semiconductor device manufacturing process.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present application and therefore may include information that does not constitute prior art known to a person of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide a preparation method of a semiconductor device, which can relieve the condition that a photoresist and a second anti-reflection layer have a low film retention phenomenon and ensure the excellent rate in the preparation process of the semiconductor device.

The application provides a preparation method of a semiconductor device, which comprises the following steps:

providing a target to be etched;

forming a first mask layer on the surface of the target to be etched;

forming a first anti-reflection layer on the surface of the first mask layer;

forming a second mask layer on the surface of the first anti-reflection layer;

forming a second anti-reflection layer on a surface of the second mask layer in a reaction gas containing nitrogen;

forming a photoresist mask pattern on the surface of the second anti-reflection layer;

etching the second anti-reflection layer and the second mask layer by using the photoresist mask pattern as an etching mask so as to form a first intermediate mask pattern on the first anti-reflection layer, wherein the first intermediate mask pattern comprises a second mask sublayer and a second anti-reflection sublayer;

forming a dielectric layer on the first anti-reflection layer and the first intermediate mask pattern, wherein the dielectric layer comprises a side wall formed at the side part of the first intermediate mask pattern;

etching the other parts of the first anti-reflection layer except the side wall to form a second intermediate mask pattern;

and etching the first anti-reflection layer and the first mask layer by using the second intermediate mask pattern as an etching mask so as to form a target pattern on the target to be etched.

In one exemplary embodiment of the present application, the second anti-reflection layer includes silicon oxynitride.

In an exemplary embodiment of the present application, in the process of forming the second anti-reflective layer on the surface of the second mask layer, the second anti-reflective layer is deposited at a rate of 0.2nm/sec to 1.0nm/sec, at a temperature of 250 ℃ to 500 ℃, under a pressure of 3to 10 torr, and at a radio frequency power of 100W to 300W.

In an exemplary embodiment of the present application, the reaction gas further includes monosilane gas, nitrous oxide gas, and helium gas.

In an exemplary embodiment of the present application, in the forming of the second anti-reflective layer on the surface of the second mask layer, a flow rate of the monosilane gas is 200 seem to 600 seem, a flow rate of the nitrous oxide gas is 300 seem to 1000 seem, a flow rate of the helium gas is 8000 seem to 12000 seem, and a flow rate of the nitrogen gas is 2000 seem to 5000 seem.

In an exemplary embodiment of the present application, the reaction gas further includes one or more of nitric oxide gas, nitrogen dioxide, and dinitrogen tetroxide.

In an exemplary embodiment of the present application, the target to be etched includes one or more of silicon dioxide, polysilicon, and silicon nitride.

In an exemplary embodiment of the present application, the first mask layer and the second mask layer each include amorphous carbon, and the first anti-reflection layer includes silicon oxynitride.

In an exemplary embodiment of the present application, the forming of the photoresist mask pattern on the surface of the second anti-reflection layer includes:

forming photoresist on the surface of the second anti-reflection layer;

and carrying out photoetching process on the photoresist by adopting a photomask plate with a pattern.

In an exemplary embodiment of the present application, the etching the other portions of the first anti-reflection layer except for the sidewalls to form a second intermediate mask pattern includes:

performing an anisotropic etching process on the dielectric layer to etch the other parts except the first intermediate mask pattern and the side walls;

etching the first intermediate mask pattern to form the second intermediate mask pattern.

The technical scheme provided by the application can achieve the following beneficial effects:

according to the preparation method of the semiconductor device, when the second antireflection layer is formed on the surface of the second mask layer, the reaction gas containing nitrogen can be added, and the generation of N-H bonds in the second antireflection layer can be reduced, so that the condition that the photoresist and the second antireflection layer have low film retention is relieved, the condition that the line width is changed after an etching process is relieved, and the excellent rate of the semiconductor device in the preparation process is ensured.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic view after photolithography in the related art;

fig. 2 is a flowchart of a method of manufacturing a semiconductor device according to an embodiment of the present application;

FIG. 3 is a flowchart of step S106 in FIG. 2;

FIG. 4 is a flowchart of step S112 in FIG. 2;

FIG. 5 is a schematic diagram of the step S100 in FIG. 2;

fig. 6 is a schematic diagram of the process after step S102 in fig. 2 is completed;

FIG. 7 is a schematic diagram of the step S104 in FIG. 2;

fig. 8 is a schematic diagram of the process after step S1061 in fig. 3;

fig. 9 is a schematic diagram of the process after step S1062 in fig. 3;

fig. 10 is a schematic diagram of the process after step S108 in fig. 2 is completed;

fig. 11 is a schematic diagram of the process after step S110 in fig. 2 is completed;

FIG. 12 is a schematic diagram of the step S112 in FIG. 2;

fig. 13 is a schematic diagram after step S114 in fig. 2 is completed.

Description of reference numerals:

in fig. 1:

10. an anti-reflection layer; 11. and (7) photoresist.

In fig. 5to 13:

20. a silicon dioxide layer; 21. a polysilicon layer; 22. a first mask layer; 221. a first mask sublayer; 23. a first anti-reflection layer; 231. a first anti-reflective sublayer; 24. a second mask layer; 241. a second mask sublayer; 25. a second anti-reflection layer; 251. a second anti-reflective sublayer; 26. photoresist; 260. a photoresist mask pattern; 27. a dielectric layer; 271. and a side wall.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said" are used to indicate the presence of one or more elements/components/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first" and "second", etc. are used merely as labels, and are not limiting on the number of their objects.

As the size of semiconductor devices continues to shrink, the pattern transfer requirements during photolithography are also more precise. The increasing demand for resolution of photoresist as an important tool for assisting pattern transfer in the photolithography process, accompanied by the reduction in photolithography size, has led to the shift of photolithography to deep ultraviolet short wavelengths, such as: from 248nm to 193 nm. However, in the photolithography and development process, as shown in fig. 1, when the anti-reflection layer 10 at the bottom of the photoresist 11 is made of silicon oxynitride (SiON), the photoresist 11 and the surface layer of SiON may have a low film remaining phenomenon, as shown in the region a in fig. 1, which further causes a variation in the line width after etching, thereby reducing the yield in the semiconductor device manufacturing process.

The embodiment provides a manufacturing method of a semiconductor device, which is used for manufacturing the semiconductor device. As shown in fig. 2, the preparation method of the present embodiment may include:

step S100, providing a target to be etched;

step S101, forming a first mask layer on the surface of a target to be etched;

step S102, forming a first anti-reflection layer on the surface of the first mask layer;

step 103, forming a second mask layer on the surface of the first anti-reflection layer;

step S104, forming a second antireflection layer on the surface of the second mask layer in the reaction gas containing nitrogen;

step S105, forming a photoresist mask pattern on the surface of the second anti-reflection layer;

step S106, using the photoresist mask pattern as an etching mask, etching the second anti-reflection layer and the second mask layer to form a first intermediate mask pattern on the first anti-reflection layer, wherein the first intermediate mask pattern comprises a second mask sub-layer and a second anti-reflection sub-layer;

step S107, forming a dielectric layer on the first antireflection layer and the first intermediate mask pattern, wherein the dielectric layer comprises a side wall formed at the side part of the first intermediate mask pattern;

step S108, etching the other parts of the first anti-reflection layer except the side wall to form a second intermediate mask pattern;

step S109, using the second intermediate mask pattern as an etching mask, the first anti-reflection layer and the first mask layer are etched to form a target pattern on the object to be etched.

According to the preparation method of the embodiment, when the second antireflection layer is formed on the surface of the second mask layer, the reaction gas containing nitrogen can be added to reduce the generation of N-H bonds in the second antireflection layer, so that the condition that the photoresist and the second antireflection layer have low film retention is relieved, the condition that the line width is changed after an etching process is relieved, and the excellent rate of the semiconductor device in the preparation process is ensured.

The steps of the preparation method of the embodiment of the present application are described in detail below with reference to the accompanying drawings:

as shown in fig. 2 and 5, in step S100, an object to be etched is provided.

The target to be etched may comprise one or more of silicon dioxide, polysilicon and silicon nitride. For example, the target to be etched is a stacked structure, and the target to be etched may include, but is not limited to, a silicon dioxide layer 20 and a polysilicon layer 21. The polysilicon layer 21 may be formed on the silicon dioxide layer 20, and may be deposited on the silicon dioxide layer 20 by LPCVD (Low Pressure chemical vapor Deposition).

As shown in fig. 2 and 5, in step S101, a first mask layer 22 is formed on the surface of the object to be etched.

The first mask layer 22 may include amorphous carbon, but is not limited thereto. The amorphous carbon can be formed on the target to be etched, specifically, can be formed on the polysilicon layer 21 of the target to be etched by a direct current magnetron sputtering method.

As shown in fig. 2 and 5, in step S102, a first anti-reflection layer 23 is formed on the surface of the first mask layer 22.

The first anti-reflective layer 23 may include silicon oxynitride, but is not limited thereto. The silicon oxynitride is formed on the first mask layer 22, and may be deposited on the first mask layer 22 by PECVD (Plasma Enhanced Chemical Vapor Deposition). The first anti-reflective layer 23 can alleviate the reflection of light on the surface of the first mask layer 22.

As shown in fig. 2 and 6, in step S103, a second mask layer 24 is formed on the surface of the first anti-reflection layer 23.

The second mask layer 24 may include amorphous carbon, but is not limited thereto. The amorphous carbon may be formed on the first anti-reflection layer 23 by a dc magnetron sputtering method.

As shown in fig. 2 and 7, in step S104, a second anti-reflection layer 25 is formed on the surface of the second mask layer 24 in a reaction gas including nitrogen.

For example, the second anti-reflective layer 25 may comprise silicon oxynitride. The silicon oxynitride may be deposited on the second mask layer 24 by PECVD, and the second anti-reflection layer 25 may alleviate the reflection of light on the surface of the second mask layer 24, thereby increasing the accuracy of the subsequently formed photoresist mask pattern 260. In the process of depositing silicon oxynitride on the second mask layer 24 by PECVD, a reaction gas containing nitrogen may be added, that is, nitrogen in the reaction gas may be used as one of the reactants, so that the processed second anti-reflection layer 25 has fewer N-H bonds, thereby achieving the purpose of improving the etching line width.

Wherein, in the process of forming the second anti-reflection layer 25 on the surface of the second mask layer 24, the deposition rate of the second anti-reflection layer 25 is 0.2nm/sec to 1.0nm/sec, such as: 0.2nm/sec, 0.4nm/sec, 0.6nm/sec, 0.8nm/sec, 1.0nm/sec, etc.; the temperature is 250-500 ℃, such as: 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃ and the like; the pressure is 3tor to 10tor, such as: 3tor, 5tor, 7tor, 10tor, etc.; the radio frequency power is 100W-300W, such as: 100W, 200W, 300W, etc.

In the present embodiment, the deposition effect of the second anti-reflection layer 25 can be ensured by setting the parameters in the deposition process of the second anti-reflection layer 25 within the above ranges.

In this embodiment, the reaction gas may further include monosilane gas (SiH4), nitrous oxide gas (N2O), and helium gas (He).

During the deposition of the second anti-reflection layer 25 on the second mask layer 24, the flow rate of the monosilane gas is 200sccm to 600sccm, such as: 200sccm, 300sccm, 400sccm, 500sccm, 600sccm, etc.; the flow rate of the nitrous oxide gas is 300sccm to 1000sccm, such as: 300sccm, 500sccm, 700sccm, 1000sccm, etc.; the flow rate of helium is 8000sccm to 12000sccm, such as: 8000sccm, 10000sccm, 12000sccm, etc.; the flow rate of the nitrogen is 2000 sccm-5000 sccm, such as: 2000sccm, 3000sccm, 4000sccm, 5000sccm, 6000sccm, etc.

The reaction gas may also include one or more of nitric oxide gas (NO), nitrogen dioxide (NO2) and dinitrogen tetroxide (N2O4), which can further reduce the generation of N-H bonds in the second anti-reflection layer and improve the etching line width.

In step S105, a photoresist mask pattern 260 is formed on the surface of the second anti-reflection layer 25.

The method of forming the photoresist mask pattern 260 may include steps S1051 and S1052, in which:

as shown in fig. 3 and 8, in step S1051, a photoresist 26 is formed on the surface of the second anti-reflection layer 25.

For example, the photoresist 26 may be formed on the second anti-reflection layer 25 using a spin coating method, but is not limited thereto, and the photoresist 26 may also be formed on the second anti-reflection layer 25 by one or more processes of a dip coating method, an air knife coating method, a curtain coating method, a wire bar method, a concave coating method, a lamination method, an extrusion coating method.

As shown in fig. 3, in step S1052, a photolithography process is performed on the photoresist 26 using a photomask having a pattern.

The photolithography process may include exposure and development, that is, the photoresist 26 may be sequentially exposed and developed using a patterned photomask to form a photoresist mask pattern 260 on the second anti-reflection layer 25, as shown in fig. 9.

As shown in fig. 2 and 10, in step S106, the second anti-reflection layer 25 and the second mask layer 24 are etched using the photoresist mask pattern 260 as an etching mask to form a first intermediate mask pattern on the first anti-reflection layer 23. At this time, the remaining portions of the first anti-reflection layer 23 except for the portions where the first intermediate mask patterns are formed are exposed. The first intermediate mask pattern includes a second mask sublayer 241 and a second antireflection sublayer 251, the second mask sublayer 241 belongs to the second mask layer 24, and the second mask sublayer 241 is an unetched part on the second mask layer 24; similarly, the second anti-reflection sub-layer 251 belongs to the second anti-reflection layer 25, and the second anti-reflection sub-layer 251 is an unetched portion of the second anti-reflection layer 25.

After the first intermediate mask pattern is formed, the photoresist 26 remaining on the first intermediate mask pattern may be removed.

As shown in fig. 2 and 11, in step S107, a dielectric layer 27 is formed on the first anti-reflective layer 23 and the first intermediate mask pattern, wherein the dielectric layer 27 may include sidewalls 271 formed at sides of the first intermediate mask pattern.

For example, the dielectric layer 27 may be deposited on the exposed portion of the first anti-reflection layer 23 and on the top and side portions of the first intermediate mask pattern using PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition). The dielectric layer 27 may comprise an insulating material such as silicon dioxide (SiO 2).

As shown in fig. 2 and 12, in step S108, the portions of the first anti-reflection layer 23 except for the side walls 271 are etched to form a second intermediate mask pattern.

As shown in fig. 4, the method of forming the second intermediate mask pattern may include steps S1081 and S1082, wherein:

in step S1081, an anisotropic etching process is performed on the dielectric layer 27 to etch portions other than the first intermediate mask pattern and the sidewall spacers 271.

For example, the anisotropic etching process may be performed using a hydrofluorocarbon gas such as tetrafluoromethane (CF4) and trifluoromethane (CHF3) as an etching gas to etch portions other than the first intermediate mask pattern and the side walls 271, that is: the remaining portion of the aforementioned first anti-reflection layer 23 is exposed, and the top of the first intermediate mask pattern is exposed.

In step S1082, the first intermediate mask pattern is etched to form a second intermediate mask pattern. The second intermediate mask pattern includes a sidewall 271 formed on the first anti-reflection layer 23, as shown in fig. 12.

As shown in fig. 1 and 13, in step S109, the first anti-reflection layer 23 and the first mask layer 22 are etched using the second intermediate mask pattern as an etching mask to form a target pattern on the object to be etched.

After the target pattern is formed, the second intermediate mask pattern remaining on the target pattern may be removed.

It should be noted that the remaining portion of the target to be etched except for the portion where the target pattern is formed is exposed, that is, the remaining portion of the polysilicon layer 21 of the target to be etched except for the portion where the target pattern is formed is exposed. The target pattern comprises a first anti-reflection sublayer 231 and a first mask sublayer 221, wherein the first anti-reflection sublayer 231 belongs to the first anti-reflection layer 23, and the first anti-reflection sublayer 231 is an unetched part on the first anti-reflection layer 23; similarly, the first mask sub-layer 221 belongs to the first mask layer 22, and the first mask sub-layer 221 is an unetched portion of the first mask layer 22.

Further, the first mask layer 22 and the first anti-reflection layer 23 formed together and the second mask layer 24 and the second anti-reflection layer 25 formed together in this embodiment may be respectively regarded as one integral structure, and it should be understood that the integral structure is not limited to two, and three, four, etc. may be provided in this application to improve the mask accuracy.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.