Process method of semiconductor device and semiconductor device

Abstract

The invention provides a process method of a semiconductor device and the semiconductor device, and the process method of the semiconductor device comprises the following steps: carrying out the plasma treatment of a silicon substrate through a decoupling plasma process, so as to enable at least part of the surface, facing the plasma injection direction, of the silicon substrate to form a pretreatment layer; and carrying out oxidation treatment on the surface of the silicon substrate by adopting an oxidation process so as to generate an oxide layer on the surface of the silicon substrate. According to the method, the silicon substrate is subjected to plasma treatment and then oxidation treatment by adopting a decoupling plasma process, so that the growth rate of the oxide in the plasma treatment region is increased, the growth rate difference between different crystal faces is reduced, and the selective control on the thickness of the oxide can be realized; and the uniformity of the film in the same action time is better.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a process method for a semiconductor device and a semiconductor device. Background Art

[0002] In the thin film growth method of consuming Si substrate to form silicon oxide (SiO2), there is a phenomenon that the growth rate of oxide film is different between different crystal planes. For example, when there is a trench with a high aspect ratio in the device structure, the oxide growth rate of the trench sidewall will be faster than the oxide growth rate of the trench top. Therefore, within the same action time, the thickness of the oxide film on the trench sidewall will be greater than the thickness of the oxide film at the top of the trench, which will lead to poor uniformity of the device film. At the same time, the growth rate difference between different crystal planes, and the atmosphere environment at the bottom of the trench caused by the high aspect ratio is different from the wafer plane or the protrusion position, will also cause the oxide thickness at the bottom plane of the trench to be less than the oxide thickness on the wafer plane or the upper surface of the protrusion shape, that is, the top of the trench. If the growth rate of the oxide film on the same device is different due to the difference in graphics, the thickness obtained at the same time will be uneven, resulting in poor uniformity, which may cause the electrical performance of the final device to degrade.

[0003] During semiconductor processing, this structural difference caused by the pattern makes it inevitable that the growth rate of different pattern structure areas will be different during oxide growth. In response to this physical crystal orientation dependence problem, the performance will be more serious in the traditional furnace tube process at the beginning. Later, in important thin film process steps with high film quality requirements (usually less than 100A), the in-situ water vapor oxidation process (ISSG) is usually selected to replace the traditional furnace tube film growth process. Because compared with the furnace tube thermal oxidation process, when growing films of the same film thickness, the overall growth rate of ISSG is faster and the process action time is shorter, so that the thickness difference of the oxide film on different crystal planes will be smaller. However, although the in-situ water vapor oxidation method can improve the thickness unevenness caused by this pattern difference to a certain extent and reduce the thickness difference between different crystal planes, it cannot completely eliminate this crystallographic difference.

[0004] Therefore, it is necessary to provide a novel process method for a semiconductor device and a semiconductor device to solve the above problems existing in the prior art. Summary of the Invention

[0005] The object of the present invention is to provide a process method for a semiconductor device and a semiconductor device, which adopts a decoupled plasma process to perform plasma treatment on a silicon substrate and then perform oxidation treatment, which is beneficial to increasing the growth rate of the oxide in the plasma-treated area, reducing the growth rate difference between different crystal planes, and realizing selective control of the oxide thickness, so that the uniformity of the film is better within the same exposure time.

[0006] To achieve the above object, the process method of the semiconductor device of the present invention comprises the following steps:

[0007] S1. Plasma-treating a silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing a plasma jet direction;

[0008] S2. Oxidizing the surface of the silicon substrate using an oxidation process to generate an oxide layer on the surface of the silicon substrate.

[0009] The semiconductor device of the present invention is manufactured using the process method of the semiconductor device.

[0010] The process method of the semiconductor device of the present invention and the semiconductor device manufactured using the process method of the semiconductor device have the beneficial effects of: by performing an inductively decoupled plasma process on the silicon substrate in step S1 before the oxide layer grows, at least a portion of the surface of the silicon substrate facing the plasma injection direction is bombarded by the plasma and destroyed, causing the silicon lattice to change, so that in step S2, the reactive oxygen can more easily reach the interface between the oxide and the silicon base during the process of generating silicon oxide, i.e., the oxide layer, so that the rate of oxide formation in the area of ​​the silicon substrate subjected to plasma treatment is faster than that in the area not subjected to plasma treatment, thereby increasing the thickness of the oxide layer in the area subjected to plasma treatment. That is, using the decoupled plasma process to plasma-treat the silicon substrate is beneficial to increasing the growth rate of the oxide in the area subjected to plasma treatment, reducing the growth rate difference between different crystal planes, and realizing selective control of the oxide thickness, so that the uniformity of the film is better within the same exposure time. At the same time, the plasma ejected by the decoupled plasma process has a higher ion density and lower ion energy. Furthermore, when the power is increased, the decoupled plasma process tends to increase the ion density rather than the ion energy, making it easier to pretreat the surface of the silicon substrate and the Si near the surface without allowing the plasma to reach deep into the silicon substrate. This prevents the formation of a thick pretreatment layer. If the pretreatment layer is thick, but only a portion of the Si in the pretreatment layer is consumed to form an oxide layer of predetermined thickness, the remaining thickness of the pretreatment layer will cause defects in the silicon substrate, ultimately affecting the reliability or electrical properties of the semiconductor device. In other words, the decoupled plasma process can enhance the surface pretreatment effect by increasing the ion density, but because the energy is not significantly increased, it avoids excessive damage or defects deep inside the silicon substrate.

[0011] Preferably, before step S1, the method further includes step S0: providing the silicon substrate, wherein the silicon substrate includes at least one trench; in step S1, the step of plasma-treating the silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing the plasma jet direction includes the step of spraying plasma on the silicon substrate using the decoupled plasma process to form the pre-treated layer on at least one of the bottom, top, and sidewalls of the trench facing the plasma jet direction. This method has the beneficial effect of causing the rate of oxide formation at the top and bottom of the trench with a high aspect ratio to be greater than the rate of oxide formation on the sidewalls, thereby reducing the difference in oxide layer thickness between the top and bottom of the trench and the sidewalls, and improving the uniformity of oxide coverage caused by pattern differences, that is, reducing the differences caused by pattern results and improving the uniformity of oxide film coverage.

[0012] Preferably, in step S1, the duration of the plasma treatment is controlled to be 60 to 180 seconds, and the power of the plasma treatment is controlled to be 1000 to 2250 W. The beneficial effects are: if the plasma treatment duration is too short, the silicon lattice on the surface of the silicon substrate bombarded by ions will not be destroyed, resulting in failure to achieve the purpose of increasing the oxide growth rate; if the plasma treatment duration is too long, the effect of increasing the oxide growth rate is reduced, and the overall process time is extended, and the investment cost is increased; the power of the plasma treatment is conducive to destroying the silicon lattice on the surface of the silicon substrate bombarded by ions, thereby achieving the purpose of increasing the oxide growth rate.

[0013] Preferably, in step S1, the process gas used in the decoupled plasma process is nitrogen, and the flow rate of the nitrogen is controlled to be 200-2000 sccm. The beneficial effect is that the main acting ions in the pretreatment process are N2 + , N2 + After being injected into the silicon substrate, it does not show electrical properties, so that it can destroy the silicon lattice on the surface of the silicon substrate and will not cause other substances to form on the surface of the silicon substrate. + After implantation into the silicon substrate, the nitrogen gas exhibits no electrical properties, preventing interference with the implanted ions in the ion regions used for other functions, created by the ion implantation (IMP) process, thereby avoiding any impact on the device's electrical properties. The nitrogen gas flow rate is beneficial for disrupting the silicon lattice on the ion-bombarded surface of the silicon substrate, thereby increasing the oxide growth rate.

[0014] Preferably, in step S1, the pressure used in the decoupled plasma process is controlled to be 10-80 mTorr, which has the beneficial effect of destroying the silicon lattice on the surface of the silicon substrate bombarded by ions, thereby achieving the purpose of increasing the oxide growth rate.

[0015] Preferably, in step S2, the oxidation process is an in-situ steam oxidation process, which has the beneficial effects of faster overall ISSG growth rate, shorter process time, and smaller thickness differences of oxide films on different crystal planes.

[0016] Preferably, the surface of the silicon substrate includes a first region and a second region; in step S1, the decoupled plasma process is used to perform plasma treatment on the first region to form the pretreatment layer in the first region; in step S2, the oxidation process is used to perform oxidation treatment on the first region and the second region to form a first oxide layer in the first region and a second oxide layer in the second region. The beneficial effect is that because the first region is pretreated, the oxide growth rate in the first region is greater than the oxide growth rate in the second region, so that the thickness of the first oxide layer is greater than the thickness of the second oxide layer. That is, through this process method, oxide layers of different thicknesses can be produced in different regions of the silicon substrate on the same machine, without the need to perform machine transfer processing to produce oxide layers of different thicknesses in different regions of the silicon substrate, which greatly saves cost investment and shortens process time. It is suitable for preparing oxide films with a specific thickness distribution.

[0017] Preferably, the surface of the silicon substrate includes a first region and a second region; in step S1, the decoupled plasma process is used to perform plasma treatment on the first region and the second region, so that a first pretreatment layer is formed in the first region and a second pretreatment layer is formed in the second region, and the plasma treatment time of the first region is controlled to be longer than the plasma treatment time of the second region; in step S2, the oxidation process is used to perform oxidation treatment on the first region and the second region, so that a first oxide layer is formed in the first region and a second oxide layer is formed in the second region. The beneficial effect is that because the plasma treatment time of the first region is longer than the plasma treatment time of the second region, the oxide growth rate of the first region is greater than the oxide growth rate of the second region, so that the thickness of the first oxide layer is greater than the thickness of the second oxide layer. That is, through this process method, oxide layers of different thicknesses can be produced in different regions of the silicon substrate on the same machine, without the need to perform machine transfer processing to produce oxide layers of different thicknesses in different regions of the silicon substrate, which greatly saves cost investment and shortens process time. It is suitable for preparing oxide films with a specific thickness distribution.

[0018] Preferably, before step S1, the following steps are further performed: using a DHF solution to clean the surface of the silicon substrate in an acid tank, or spraying the DHF solution on the front and back sides of the silicon substrate, wherein the DHF solution used to clean the silicon substrate is composed of a mixture of a 49% by mass HF solution and water in a volume ratio of 1:50 to 1:500, and the cleaning time is controlled to be 0.5 to 5 minutes. This has the beneficial effect of removing oxides generated by oxidation of the silicon substrate surface due to contact with oxygen in the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a process for a semiconductor device according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of the silicon substrate in the first embodiment of the present invention;

[0021] Figure 3 The first embodiment of the present invention uses a decoupled plasma process to Figure 2 Schematic diagram of the structure formed after the silicon substrate is plasma treated;

[0022] Figure 4 In the first embodiment of the present invention, an in-situ steam oxidation process is used to Figure 3 Schematic diagram of the structure formed after the structure shown is oxidized;

[0023] Figure 5 Schematic diagram of the structure of the silicon substrate in the second embodiment and the third embodiment of the present invention;

[0024] Figure 6 The second embodiment of the present invention uses a decoupled plasma process to Figure 5 Schematic diagram of the structure formed after the silicon substrate is plasma treated;

[0025] Figure 7 In the second embodiment of the present invention, an in-situ steam oxidation process is used to Figure 6 Schematic diagram of the structure formed after the structure shown is oxidized;

[0026] Figure 8 The third embodiment of the present invention uses a decoupled plasma process to Figure 5 Schematic diagram of the structure formed after the silicon substrate is plasma treated;

[0027] Figure 9 In the third embodiment of the present invention, an in-situ steam oxidation process is used to Figure 8 Schematic diagram of the structure formed after the structure shown is oxidized;

[0028] Figure 10 A transmission electron microscope scanning diagram of a structure formed after the silicon substrate is treated by a decoupled plasma process in Example 1;

[0029] Figure 11 Schematic diagram of a transmission electron microscope scan of a structure formed after the silicon substrate in Comparative Example 1 is treated by an in-situ water vapor oxidation process;

[0030] Figure 12 This is a transmission electron microscope scanning diagram of the structure formed after the silicon substrate is treated with a decoupled plasma process and an in-situ water vapor oxidation process in Example 1;

[0031] Figure 13 for Figures 10 to 12 A schematic diagram of a local magnified transmission electron microscope scan of the structure shown;

[0032] Figure 14 Schematic diagram of the thickness of the oxide layer in the semiconductor device of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0034] To overcome the problems existing in the prior art, an embodiment of the present invention provides a process method for a semiconductor device and a semiconductor device, wherein a decoupled plasma process is used to perform plasma treatment on a silicon substrate and then an oxidation treatment is performed, which is beneficial to increasing the growth rate of the oxide in the plasma-treated area and reducing the growth rate difference between different crystal planes. Selective control of the oxide thickness can be achieved, thereby improving the uniformity of the thin film within the same exposure time.

[0035] Figure 1 Schematic diagram of a process for a semiconductor device according to an embodiment of the present invention.

[0036] In some embodiments of the present invention, reference Figure 1 , the process method of the semiconductor device comprises the following steps:

[0037] S1. Plasma-treating a silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing a plasma jet direction;

[0038] S2. Oxidizing the surface of the silicon substrate using an oxidation process to generate an oxide layer on the surface of the silicon substrate.

[0039] Specifically, by performing an inductively decoupled plasma process on the silicon substrate in step S1 before the oxide layer grows, at least a portion of the surface of the silicon substrate facing the plasma injection direction is destroyed by plasma bombardment, causing the silicon lattice to change, so that the reactive oxygen in step S2 can more easily reach the interface between the oxide and the silicon base during the process of generating silicon oxide, i.e., the oxide layer, so that the rate of oxide formation in the plasma-treated area of ​​the silicon substrate is faster than that in the non-plasma-treated area, thereby increasing the thickness of the oxide layer in the plasma-treated area. That is, the decoupled plasma process is used to plasma-treat the silicon substrate, which is beneficial to increasing the growth rate of the oxide in the plasma-treated pretreatment layer, reducing the growth rate difference between different crystal planes, and realizing selective control of the oxide thickness, so that the uniformity of the film is better within the same exposure time.

[0040] At the same time, the decoupled plasma nitridation (DPN) process, also known as the decoupled plasma nitriding process, sprays plasma with a higher ion density and lower ion energy. Furthermore, as the power is increased, the ion density tends to increase rather than the ion energy, making it easier to pretreat the surface of the silicon substrate and the Si near the surface without allowing the plasma to reach deep within the silicon substrate. This prevents the formation of a thick pretreatment layer. If the pretreatment layer is thick, but only a portion of the Si in the pretreatment layer is consumed to form an oxide layer of predetermined thickness, the remaining thickness of the pretreatment layer will cause defects in the silicon substrate, ultimately affecting the reliability or electrical properties of the semiconductor device. In other words, the use of DPN can enhance the surface pretreatment effect by increasing the ion density, but because the energy does not increase significantly, it avoids excessive damage or defects deep within the silicon substrate.

[0041] In some embodiments of the present invention, the step S1 further includes the following steps: performing a surface cleaning treatment on the silicon substrate using a DHF solution in an acid tank, or spraying the DHF solution on the front and back sides of the silicon substrate, and controlling the DHF solution for cleaning the silicon substrate to be a mixture of a 49% by mass HF solution and water in a volume ratio of 1:50 to 1:500, and controlling the cleaning time to be 0.5 to 5 minutes, so as to remove oxides generated by oxidation of the surface of the silicon substrate due to contact with oxygen in the environment.

[0042] In some specific embodiments of the present invention, the step S1 may further include the following steps: performing surface cleaning on the silicon substrate using a DHF solution in an acid tank. Specifically, the surface cleaning may be performed on multiple silicon substrates using the DHF solution in the acid tank.

[0043] In some other specific embodiments of the present invention, the step S1 further includes the following steps: spraying the DHF solution on the front and back sides of the silicon substrate to perform surface cleaning on the silicon substrate.

[0044] In some specific embodiments of the present invention, the DHF solution for cleaning the silicon substrate is composed of a mixture of 49% by mass HF solution and water in a volume ratio of any one of 1:50, 1:70, 1:100, 1:150, 1:180, 1:200, 1:225, 1:275, 1:300, 1:330, 1:360, 1:400, 1:450 and 1:500.

[0045] In some specific embodiments of the present invention, the cleaning time is controlled to be any one of 0.5 min, 1 min, 1.2 min, 1.8 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min and 5 min.

[0046] In some specific embodiments of the present invention, the DHF solution for cleaning the silicon substrate is controlled to be a mixture of 49% by mass HF solution and water in a volume ratio of 1:100, and the cleaning time is controlled to be less than 1 minute.

[0047] In some embodiments of the present invention, in step S1, the duration of the plasma treatment is controlled to be 60 to 180 seconds, and the power of the plasma treatment is controlled to be 1000 to 2250 W. If the plasma treatment duration is too short, the silicon lattice on the surface of the silicon substrate bombarded by ions will not be destroyed, resulting in failure to achieve the purpose of increasing the oxide growth rate; if the plasma treatment duration is too long, the effect of increasing the oxide growth rate is reduced, and the overall process time is extended, increasing the investment cost; the power of the plasma treatment is conducive to destroying the silicon lattice on the surface of the silicon substrate bombarded by ions, thereby achieving the purpose of increasing the oxide growth rate.

[0048] In some specific embodiments of the present invention, in step S1, the duration of the plasma treatment is controlled to be any one of 60s, 80s, 100s, 120s, 135s, 150s, 160s, 175s and 180s.

[0049] In some specific embodiments of the present invention, in step S1, the power of the plasma treatment is controlled to be any one of 1000W, 1200W, 1500W, 1750W, 2000W, 2100W and 2250W.

[0050] In some embodiments of the present invention, in step S1, the process gas used in the decoupled plasma process is nitrogen, and the flow rate of the nitrogen is controlled to be 200-2000 sccm. That is, the main active ions in the pretreatment process are N2 + , N2 + After being injected into the silicon substrate, it does not show electrical properties, so that it can destroy the silicon lattice on the surface of the silicon substrate and will not cause other substances to form on the surface of the silicon substrate. + After implantation into the silicon substrate, the nitrogen gas exhibits no electrical properties, preventing interference with the implanted ions in the ion regions used for other functions, created by the ion implantation (IMP) process, thereby avoiding any impact on the device's electrical properties. The nitrogen gas flow rate is beneficial for disrupting the silicon lattice on the ion-bombarded surface of the silicon substrate, thereby increasing the oxide growth rate.

[0051] In some specific embodiments of the present invention, in step S1, the flow rate of the nitrogen gas is controlled to be any one of 200sccm, 240sccm, 280sccm, 300sccm, 350sccm, 400sccm, 450sccm, 480sccm, 500sccm, 530sccm, 560sccm, 600sccm, 650sccm, 700sccm, 750sccm, 800sccm, 1000sccm, 1250sccm, 1500sccm, 1750sccm and 2000sccm.

[0052] In some embodiments of the present invention, in step S1, the pressure used in the decoupled plasma process is controlled to be 10 to 80 mtorr, which is beneficial for destroying the silicon lattice on the surface of the silicon substrate bombarded by ions, thereby achieving the purpose of increasing the oxide growth rate.

[0053] In some specific embodiments of the present invention, in step S1, the pressure used in the decoupling plasma process is controlled to be any one of 10 mTorr, 15 mTorr, 20 mTorr, 23 mTorr, 28 mTorr, 30 mTorr, 35 mTorr, 40 mTorr, 45 mTorr, 50 mTorr, 55 mTorr, 60 mTorr, 66 mTorr, 70 mTorr, 77 mTorr and 80 mTorr.

[0054] In some embodiments of the present invention, in step S2, the oxidation process is an in-situ water vapor oxidation process, the overall growth rate of ISSG is faster, and the process action time is shorter, so that the thickness difference of the oxide film on different crystal planes is smaller.

[0055] In some embodiments of the present invention, the step S2 further includes the following steps: forming a dielectric layer, performing patterning, and setting metal wiring, etc.

[0056] In some embodiments of the present invention, step S1 is preceded by step S0: providing a silicon substrate comprising at least one trench; wherein in step S1, the step of plasma-treating the silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing the plasma jet direction comprises the step of spraying plasma on the silicon substrate using the decoupled plasma process to form the pre-treated layer on at least one of the bottom, top, and sidewalls of the trench facing the plasma jet direction. This allows the rate of oxide formation at the top and bottom of the trench with a high aspect ratio to be greater than the rate of oxide formation on the sidewalls, thereby reducing the difference in oxide thickness between the top and bottom of the trench and the sidewalls, and improving the uniformity of oxide coverage caused by pattern differences, i.e., minimizing the differences caused by pattern results and improving the uniformity of oxide film coverage.

[0057] In some embodiments of the present invention, in step S1, plasma is sprayed onto the silicon substrate using a decoupled plasma process to form the pretreatment layer at the bottom and top of the trench facing the plasma spray direction. This allows the rate of oxide formation at the top and bottom of the trench with a high aspect ratio to be greater than the rate of oxide formation on the trench sidewalls, thereby reducing the difference in oxide thickness between the top and bottom of the trench and the sidewalls, and improving the uniformity of oxide coverage caused by pattern differences, i.e., minimizing the differences caused by pattern results and improving the uniformity of oxide film coverage.

[0058] In other embodiments of the present invention, in step S1, plasma is sprayed onto the silicon substrate using a decoupled plasma process to form the pretreatment layer at the trench bottom, trench top, and trench sidewalls facing the plasma spraying direction, and the plasma treatment duration at the trench top and trench bottom is controlled to be longer than the plasma treatment duration at the trench sidewalls. This increases the oxide growth rate at the trench bottom, trench top, and trench sidewalls simultaneously. However, because the plasma treatment duration at the trench top and trench bottom is longer than the plasma treatment duration at the trench sidewalls, the oxide formation rate at the trench top and trench bottom of a trench with a high aspect ratio is greater than the oxide formation rate at the trench sidewalls, thereby reducing the difference in oxide layer thickness at the trench top and trench bottom and the oxide layer thickness at the trench sidewalls.

[0059] In an embodiment of the present invention, the top of the trench is the surface of the silicon substrate located at the opening end of the trench.

[0060] Figure 2 Schematic diagram of the structure of the silicon substrate in the first embodiment of the present invention; Figure 3 The first embodiment of the present invention uses a decoupled plasma process to Figure 2 Schematic diagram of the structure formed after the silicon substrate is plasma treated; Figure 4 In the first embodiment of the present invention, an in-situ steam oxidation process is used to Figure 3 Schematic diagram of the structure formed after the structure shown is oxidized;

[0061] In some specific embodiments of the present invention, reference is made to Figures 2 to 4 , the process method of the semiconductor device comprises the following steps:

[0062] S10, providing the silicon substrate 1, wherein the silicon substrate 1 includes a plurality of trenches 2;

[0063] S11, spraying plasma 3 onto the silicon substrate 1 using a decoupled plasma process, so as to form the pre-processing layer 4 on the bottom 22 and the top 23 of the trench 2 facing the plasma spraying direction;

[0064] S12 , performing oxidation treatment on the surface of the silicon substrate 1 by using an oxidation process to form an oxide layer 5 on the surface of the silicon substrate 1 .

[0065] In some embodiments of the present invention, the surface of the silicon substrate includes a first region and a second region; in step S1, the decoupled plasma process is used to perform plasma treatment on the first region to form the pretreatment layer in the first region; in step S2, the oxidation process is used to perform oxidation treatment on the first region and the second region to form a first oxide layer in the first region and a second oxide layer in the second region. Because the first region is pretreated, the oxide growth rate in the first region is greater than the oxide growth rate in the second region, and thus the thickness of the first oxide layer is greater than the thickness of the second oxide layer. That is, this process method can produce oxide layers of different thicknesses in different regions of the silicon substrate on the same machine, without the need to perform machine transfer processing to produce oxide layers of different thicknesses in different regions of the silicon substrate, which greatly saves cost investment and shortens process time. It is suitable for preparing oxide films with a specific thickness distribution.

[0066] Figure 5 Schematic diagram of the structure of the silicon substrate in the second embodiment and the third embodiment of the present invention; Figure 6 The second embodiment of the present invention uses a decoupled plasma process to Figure 5 Schematic diagram of the structure formed after the silicon substrate is plasma treated; Figure 7In the second embodiment of the present invention, an in-situ steam oxidation process is used to Figure 6 Schematic diagram of the structure formed after the structure shown is oxidized;

[0067] In some specific embodiments of the present invention, reference is made to Figures 5 to 7 , the process method of the semiconductor device comprises the following steps:

[0068] S20, providing the silicon substrate 1, wherein the surface of the silicon substrate 1 includes a first region 11 and a second region 12;

[0069] S21, performing plasma treatment on the first region 11 using the decoupled plasma process, so that the first region 11 forms the pre-treated layer 4;

[0070] S22 , performing oxidation treatment on the first region 11 and the second region 12 by using the oxidation process to form a first oxide layer 51 in the first region 11 and a second oxide layer 52 in the second region 12 .

[0071] In some embodiments of the present invention, the surface of the silicon substrate includes a first region and a second region; in step S1, the first region and the second region are plasma-treated using the decoupled plasma process to form a first pretreatment layer in the first region and a second pretreatment layer in the second region, and the plasma treatment duration of the first region is controlled to be longer than the plasma treatment duration of the second region; in step S2, the first region and the second region are oxidized using the oxidation process to form a first oxide layer in the first region and a second oxide layer in the second region. Because the plasma treatment duration of the first region is longer than the plasma treatment duration of the second region, the oxide growth rate in the first region is greater than the oxide growth rate in the second region, and the thickness of the first oxide layer produced is greater than the thickness of the second oxide layer. That is, this process method can produce oxide layers of different thicknesses in different regions of the silicon substrate on the same machine, eliminating the need to perform machine rotation to produce oxide layers of different thicknesses in different regions of the silicon substrate, significantly saving cost and shortening process time. The method is suitable for preparing oxide films with a specific thickness distribution.

[0072] Figure 8 The third embodiment of the present invention uses a decoupled plasma process to Figure 5 Schematic diagram of the structure formed after the silicon substrate is plasma treated; Figure 9 In the third embodiment of the present invention, an in-situ steam oxidation process is used to Figure 8 Schematic diagram of the structure formed after the structure shown is oxidized;

[0073] In some specific embodiments of the present invention, reference is made to Figure 5 、 Figure 8 and Figure 9 , the process method of the semiconductor device comprises the following steps:

[0074] S30, providing the silicon substrate 1, wherein the surface of the silicon substrate 1 includes a first region 11 and a second region 12;

[0075] S31, performing plasma treatment on the first region 11 and the second region 12 using the decoupled plasma process, so that a first pretreatment layer 41 is formed in the first region 11, and a second pretreatment layer 42 is formed in the second region 12, and the plasma treatment time of the first region 11 is controlled to be longer than the plasma treatment time of the second region 12;

[0076] S32 , performing oxidation treatment on the first region 11 and the second region 12 using the oxidation process to form a first oxide layer 51 in the first region 11 and a second oxide layer 52 in the second region 12 .

[0077] In some embodiments of the present invention, the semiconductor device is manufactured using the process method of the semiconductor device.

[0078] In some specific embodiments of the present invention, the semiconductor device includes a silicon substrate and an oxide layer disposed on a surface of the silicon substrate.

[0079] Embodiment 1: A decoupled plasma process is used to perform plasma treatment on a silicon substrate to form a pretreatment layer on at least a portion of the surface of the silicon substrate facing the plasma injection direction; an in-situ water vapor oxidation process is used to oxidize the surface of the silicon substrate to generate an oxide layer on the surface of the silicon substrate.

[0080] Comparative Example 1: The surface of the silicon substrate is oxidized by adopting an in-situ water vapor oxidation process to form an oxide layer on the surface of the silicon substrate.

[0081] Figure 10 A transmission electron microscope scanning diagram of a structure formed after the silicon substrate is treated by a decoupled plasma process in Example 1; Figure 11 Schematic diagram of a transmission electron microscope scan of a structure formed after the silicon substrate in Comparative Example 1 is treated by an in-situ water vapor oxidation process; Figure 12 This is a transmission electron microscope scanning diagram of the structure formed after the silicon substrate is treated with a decoupled plasma process and an in-situ water vapor oxidation process in Example 1; Figure 13 for Figures 10 to 12 A schematic diagram of a local magnified transmission electron microscope scan of the structure shown; Figure 14Schematic diagram of the thickness of the oxide layer in the semiconductor device of Example 1 and Comparative Example 1.

[0082] Figure 13 The three transmission electron microscope (TEM) scanning diagrams in the figure are, from left to right, a locally enlarged transmission electron microscope scanning diagram of the structure formed after the silicon substrate is treated by the decoupled plasma process in Example 1, a locally enlarged transmission electron microscope scanning diagram of the structure formed after the silicon substrate is treated by the in-situ water vapor oxidation process in Comparative Example 1, and a locally enlarged transmission electron microscope scanning diagram of the structure formed after the silicon substrate is treated by the decoupled plasma process and the in-situ water vapor oxidation process in Example 1; and Figure 10 and Figure 13 The different colored layers in the first picture on the left are silicon substrate, pretreatment layer and TEM sample preparation layer from bottom to top. Figure 11 、 Figure 12 and Figure 13 The different colored layers in the first picture on the right and the middle picture are silicon substrate, oxide layer and TEM sample preparation layer from bottom to top, that is, Figure 13 The black frame is the oxide layer.

[0083] See Figure 10 and Figure 13 As can be seen from the first figure on the left, after the silicon substrate of Example 1 is plasma-treated using the decoupled plasma process, the silicon lattice near the surface of the silicon substrate changes to form a pre-treated layer.

[0084] See Figure 11 、 Figure 12 and Figure 13 It can be seen from the first figure on the right and the middle figure that the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Example 1 is treated with the decoupled plasma process and the in-situ water vapor oxidation process is greater than the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Comparative Example 1 is treated with the in-situ water vapor oxidation process. Specifically, the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Example 1 is treated with the decoupled plasma process and the in-situ water vapor oxidation process is 41.7A after TEM testing, and the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Comparative Example 1 is treated with the in-situ water vapor oxidation process is 37.8A after TEM testing. Figure 14Using a thickness gauge, the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Example 1 was treated using the decoupled plasma process and the in-situ water vapor oxidation process was measured to be 42.22 Å, while the thickness of the oxide layer in the semiconductor device formed after the silicon substrate of Comparative Example 1 was treated using the in-situ water vapor oxidation process was 38.16 Å. Tests using different instruments indicate that the thickness of the oxide layer in Example 1 is greater than that in Comparative Example 1 (it is normal for the thickness values ​​of the same sample tested using different instruments to be different but close, which is caused by factors such as the testing accuracy of the testing instruments). This shows that using the decoupled plasma process to plasma-treat the silicon substrate is beneficial for increasing the growth rate of the oxide in the plasma-treated pretreatment layer, thereby increasing the thickness of the oxide film in the plasma-treated pretreatment layer region.

[0085] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A process for a semiconductor device, characterized in that: The following steps are involved: S1. Plasma-treating a silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing a plasma jet direction; S2. Oxidizing the surface of the silicon substrate using an oxidation process to generate an oxide layer on the surface of the silicon substrate.

2. The process for producing a semiconductor device according to claim 1, wherein: Before step S1, step S0 is also included: providing the silicon substrate, wherein the silicon substrate includes at least one trench; In step S1, the step of plasma-treating the silicon substrate using a decoupled plasma process to form a pre-treated layer on at least a portion of the surface of the silicon substrate facing the plasma ejection direction includes: A decoupled plasma process is used to spray plasma onto the silicon substrate, so that the pretreatment layer is formed on at least one of a bottom, a top and a sidewall of the trench facing the plasma spraying direction.

3. The process for producing a semiconductor device according to claim 1 or 2, wherein: In the step S1, the duration of the plasma treatment is controlled to be 60 to 180 seconds, and the power of the plasma treatment is controlled to be 1000 to 2250W.

4. The process for producing a semiconductor device according to claim 1 or 2, wherein: In the step S1 , the process gas used in the decoupled plasma process is nitrogen, and the flow rate of the nitrogen is controlled to be 200-2000 sccm.

5. The process for producing a semiconductor device according to claim 1 or 2, wherein: In the step S1, the pressure range used in the decoupled plasma process is controlled to be 10 to 80 mTorr.

6. The process for producing a semiconductor device according to claim 1 or 2, wherein: In step S2, the oxidation process is an in-situ water vapor oxidation process.

7. The process for producing a semiconductor device according to claim 1, wherein: The surface of the silicon substrate includes a first region and a second region; In the step S1, the first region is subjected to plasma treatment using the decoupled plasma process, so that the pre-treatment layer is formed in the first region; In the step S2, the first region and the second region are oxidized using the oxidation process to form a first oxide layer in the first region and a second oxide layer in the second region.

8. The process for manufacturing a semiconductor device according to claim 1, wherein: The surface of the silicon substrate includes a first region and a second region; In step S1, the decoupled plasma process is used to perform plasma treatment on the first region and the second region, so that a first pretreatment layer is formed in the first region and a second pretreatment layer is formed in the second region, and the plasma treatment time of the first region is controlled to be longer than the plasma treatment time of the second region; In the step S2, the first region and the second region are oxidized using the oxidation process to form a first oxide layer in the first region and a second oxide layer in the second region.

9. The process for manufacturing a semiconductor device according to claim 1, wherein: Before step S1, the following steps are also included: The surface of the silicon substrate is cleaned using a DHF solution in an acid tank, or the DHF solution is sprayed on the front and back surfaces of the silicon substrate. The DHF solution used to clean the silicon substrate is controlled to be a mixture of a 49% by mass HF solution and water in a volume ratio of 1:50 to 1:500, and the cleaning time is controlled to be 0.5 to 5 minutes.

10. A semiconductor device, characterized in that: The semiconductor device is manufactured using the process method according to any one of claims 1 to 9.

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