阅读说明：本技术 化学气相沉积方法和装置 (Chemical vapor deposition method and apparatus ) 是由 许芷萍 黄欣欣 于 2019-09-09 设计创作，主要内容包括：本发明提供了一种化学气相沉积方法和装置,所述化学气相沉积方法包括在衬底上沉积目标膜层的化学气相沉积过程；在所述化学气相沉积过程开始时,反应腔的加热温度为初值温度；在所述化学气相沉积过程结束时,反应腔的加热温度为终值温度；所述终值温度低于所述初值温度；在所述化学气相沉积过程中,所述加热温度由所述初值温度降低至所述终值温度。本发明通过引入一种新的化学气相沉积方法和装置,通过在化学气相沉积过程中引入周期性的降温过程,改善设备及晶圆面内的温度分布,提高化学气相沉积的成膜均匀性,得到低成本高质量的成膜工艺。(The invention provides a chemical vapor deposition method and a device, wherein the chemical vapor deposition method comprises a chemical vapor deposition process for depositing a target film layer on a substrate; when the chemical vapor deposition process starts, the heating temperature of the reaction cavity is an initial temperature; when the chemical vapor deposition process is finished, the heating temperature of the reaction cavity is the final temperature; the final temperature is lower than the initial temperature; during the chemical vapor deposition, the heating temperature is reduced from the initial temperature to the final temperature. The invention introduces a new chemical vapor deposition method and a new chemical vapor deposition device, and introduces a periodic cooling process in the chemical vapor deposition process to improve the temperature distribution in equipment and a wafer surface, improve the film forming uniformity of chemical vapor deposition and obtain a low-cost high-quality film forming process.)

1. A chemical vapor deposition method is characterized by comprising a chemical vapor deposition process for depositing a target film layer on a substrate; when the chemical vapor deposition process starts, the heating temperature of the reaction cavity is an initial temperature; when the chemical vapor deposition process is finished, the heating temperature of the reaction cavity is the final temperature; the final temperature is lower than the initial temperature; during the chemical vapor deposition, the heating temperature is reduced from the initial temperature to the final temperature.

2. The chemical vapor deposition method of claim 1, wherein: the chemical vapor deposition method comprises a low-pressure chemical vapor deposition method, an atmospheric pressure chemical vapor deposition method or a plasma enhanced chemical vapor deposition method.

3. The chemical vapor deposition method of claim 1, wherein: the substrate comprises a semiconductor substrate; the target film layer includes a silicon nitride layer, a silicon dioxide layer, a single crystal silicon layer, or a polycrystalline silicon layer.

4. The chemical vapor deposition method of claim 1, wherein: the chemical vapor deposition method comprises a plurality of chemical vapor deposition processes which are sequentially carried out.

5. The chemical vapor deposition method of claim 4, wherein: the plurality of chemical vapor deposition processes have the same initial temperature at the beginning, and a temperature raising process for raising the heating temperature back to the initial temperature is further included between two adjacent chemical vapor deposition processes.

6. The chemical vapor deposition method of claim 1, wherein: the chemical vapor deposition method is used for simultaneously depositing the target film layer on a plurality of substrates, the reaction chamber is provided with a plurality of substrate placing positions, and a plurality of substrates are placed on the plurality of substrate placing positions.

7. the chemical vapor deposition method of claim 6, wherein: different ones of the substrate placement locations in the reaction chamber have different ones of the initial temperature values; the cooling rate at which the heating temperature of the substrate placement position is reduced from the initial value temperature to the final value temperature is positively correlated with the initial value temperature of the substrate placement position.

8. The chemical vapor deposition method of claim 7, wherein: the reaction cavity is a vertical cavity, a plurality of substrates are stacked in the reaction cavity along the vertical direction, the heating temperature at the top of the reaction cavity is higher than that at the bottom of the reaction cavity, and process gas participating in the chemical vapor deposition process is introduced into the reaction cavity from the bottom of the reaction cavity.

9. The chemical vapor deposition method of claim 1, wherein: the chemical vapor deposition method comprises a reaction cavity heating process, a reaction cavity heat preservation process and a reaction cavity cooling process which are sequentially carried out; the chemical vapor deposition process is included in the reaction chamber incubation process.

10. A chemical vapor deposition apparatus, characterized by: the method comprises the following steps:

The reaction chamber is used for accommodating a substrate and depositing a target film layer on the substrate through a chemical vapor deposition process;

The heating module is used for heating the reaction cavity at a heating temperature;

The temperature control module is connected with the heating module and is used for setting the heating temperature of the heating module; at the beginning of the chemical vapor deposition process, setting the heating temperature as an initial temperature; at the end of the chemical vapor deposition process, setting the heating temperature to a final value temperature; the final temperature is lower than the initial temperature; during the chemical vapor deposition, the heating temperature is reduced from the initial temperature to the final temperature.

11. the chemical vapor deposition method of claim 10, wherein: the chemical vapor deposition device also comprises a circulating control module, wherein the circulating control module is connected with the reaction cavity, the heating module and the temperature control module and is used for sequentially carrying out a plurality of chemical vapor deposition processes.

12. The chemical vapor deposition method of claim 10, wherein: the reaction cavity is a vertical cavity, and a plurality of substrate placing positions for placing the substrates are arranged in the reaction cavity along the vertical direction.

13. The chemical vapor deposition method of claim 10, wherein: the chemical vapor deposition device also comprises a process gas supply source which is connected to the bottom of the reaction chamber and is used for supplying process gas participating in the chemical vapor deposition process to the reaction chamber.

Technical Field

the invention relates to the technical field of semiconductor manufacturing, in particular to a chemical vapor deposition method and a chemical vapor deposition device.

Background

in the fabrication of semiconductor wafers, thin film deposition of various semiconductor materials is a critical technique affecting device reliability and product yield. Among them, Low Pressure Chemical Vapor Deposition (LPCVD) is widely used for depositing thin films of silicon nitride, silicon dioxide, polysilicon, or the like, and is a film formation technique for obtaining a high quality film at a low manufacturing cost.

However, as semiconductor devices continue to be developed, the size of wafers used in the manufacturing process continues to increase, and the minimum feature size continues to decrease, which places higher demands on film quality and uniformity of film deposition. For example, in the manufacturing process of a 3D NAND flash memory device, a silicon nitride material is used as an isolation layer or a mask layer material in the manufacturing process, and the film formation quality directly affects the device performance of the 3D NAND flash memory device. With the continuous reduction of 3D NAND size and the increasing complexity of structures, the silicon nitride films obtained by conventional low pressure chemical vapor deposition have failed to meet the strict requirements of the current advanced processes for film quality and uniformity. The phenomenon of uneven film formation in wafer surfaces at certain positions in LPCVD equipment or uneven film formation among wafers in the same batch often occurs in the process of low-pressure chemical vapor deposition in the same batch, so that the performance of a device is directly influenced; the position with poor film forming quality in forbidden equipment can influence the productivity of the equipment and reduce the production efficiency. In addition, if a film forming process such as Atomic Layer Deposition (ALD) which is good in uniformity but more expensive is adopted instead, the production cost of the product is directly increased, and the product competitiveness is reduced.

Therefore, there is a need for a new chemical vapor deposition method and apparatus that solves the above problems.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a chemical vapor deposition method and apparatus for solving the problem of non-uniformity of film formation in the chemical vapor deposition method of the prior art.

To achieve the above and other related objects, the present invention provides a chemical vapor deposition method, characterized in that the chemical vapor deposition method comprises a chemical vapor deposition process of depositing a target film layer on a substrate; when the chemical vapor deposition process starts, the heating temperature of the reaction cavity is an initial temperature; when the chemical vapor deposition process is finished, the heating temperature of the reaction cavity is the final temperature; the final temperature is lower than the initial temperature; during the chemical vapor deposition, the heating temperature is reduced from the initial temperature to the final temperature.

As an alternative of the present invention, the chemical vapor deposition method includes a low pressure chemical vapor deposition method, an atmospheric pressure chemical vapor deposition method, or a plasma enhanced chemical vapor deposition method.

As an alternative of the invention, the substrate comprises a semiconductor substrate; the target film layer includes a silicon nitride layer, a silicon dioxide layer, a single crystal silicon layer, or a polycrystalline silicon layer.

As an alternative of the present invention, the chemical vapor deposition method includes a plurality of the chemical vapor deposition processes performed in sequence.

As an alternative of the present invention, a plurality of the chemical vapor deposition processes have the same initial temperature at the beginning, and a temperature raising process of raising the heating temperature back to the initial temperature is further included between two adjacent chemical vapor deposition processes.

As an alternative of the present invention, the chemical vapor deposition method is for depositing the target film layer on a plurality of the substrates at the same time, and the reaction chamber has a plurality of substrate placing locations on which a plurality of the substrates are placed.

as an alternative of the invention, different ones of said substrate placement locations in said reaction chamber have different ones of said initial temperatures; the cooling rate at which the heating temperature of the substrate placement position is reduced from the initial value temperature to the final value temperature is positively correlated with the initial value temperature of the substrate placement position.

As an alternative of the present invention, the reaction chamber is a vertical chamber, a plurality of substrates are stacked in the reaction chamber along a vertical direction, the heating temperature at the top of the reaction chamber is higher than the heating temperature at the bottom of the reaction chamber, and a process gas participating in a chemical vapor deposition process is introduced into the reaction chamber from the bottom of the reaction chamber.

As an alternative of the invention, the chemical vapor deposition method comprises a reaction cavity heating process, a reaction cavity heat preservation process and a reaction cavity cooling process which are sequentially carried out; the chemical vapor deposition process is included in the reaction chamber incubation process.

The invention also provides a chemical vapor deposition device, which is characterized in that: the method comprises the following steps:

The reaction chamber is used for accommodating a substrate and depositing a target film layer on the substrate through a chemical vapor deposition process;

The heating module is used for heating the reaction cavity at a heating temperature;

The temperature control module is connected with the heating module and is used for setting the heating temperature of the heating module; at the beginning of the chemical vapor deposition process, setting the heating temperature as an initial temperature; at the end of the chemical vapor deposition process, setting the heating temperature to a final value temperature; the final temperature is lower than the initial temperature; during the chemical vapor deposition, the heating temperature is reduced from the initial temperature to the final temperature.

As an alternative of the present invention, the chemical vapor deposition apparatus further includes a circulation control module, and the circulation control module is connected to the reaction chamber, the heating module and the temperature control module, and is configured to sequentially perform a plurality of chemical vapor deposition processes.

As an alternative of the present invention, the reaction chamber is a vertical-type chamber in which a plurality of substrate placing positions where the substrates are placed are provided in a vertical direction.

As an alternative of the present invention, the chemical vapor deposition apparatus further comprises a process gas supply source connected to the bottom of the reaction chamber for supplying process gases participating in the chemical vapor deposition process to the reaction chamber.

As described above, the present invention provides a chemical vapor deposition method and apparatus having the following advantageous effects:

The invention introduces a new chemical vapor deposition method and a new chemical vapor deposition device, and introduces a periodic cooling process in the chemical vapor deposition process to improve the temperature distribution in equipment and a wafer surface, improve the film forming uniformity of chemical vapor deposition and obtain a low-cost high-quality film forming process.

Drawings

FIG. 1 is a schematic cross-sectional view of a low pressure chemical vapor deposition apparatus used in the prior art according to one embodiment of the present invention.

FIG. 2 is a graph showing the time-dependent heating temperature of the reaction chamber during the chemical vapor deposition process according to one embodiment of the present invention.

FIG. 3 is a comparison box plot of the film-forming uniformity in the wafer surface at the same position on the top of the reaction chamber provided in the first embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a chemical vapor deposition apparatus according to a second embodiment of the present invention.

Description of the element reference numerals

100 wafer

100a wafer boat

101 reaction chamber

102 heating device

103 process gas supply

103a air inlet

104 air extractor

104a exhaust port

201 top position curve

202 middle upper position curve

203 middle position curve

204 lower-middle position curve

205 bottom position curve

300 wafer

300a crystal boat

301 reaction chamber

302 heating module

302a top heating module

302b middle heating module

302c bottom heating module

303 dichlorosilane supply

303a first air inlet

304 ammonia gas supply source

304a second air inlet

305 air extractor

305a exhaust port

306 temperature control module

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.

Please refer to fig. 1 to 4. It should be noted that the drawings provided in the present embodiment are only schematic and illustrate the basic idea of the present invention, and although the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation, the form, quantity and proportion of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.