Method for measuring oxygen leakage degree of silicon-based material in RTO process and application of method

Abstract

The invention provides a method for measuring the oxygen leakage degree of a silicon-based material in the RTO process and application of the method, and belongs to the technical field of semiconductors. The measuring method comprises the following steps: placing a silicon-based material in a heat treatment device, then setting the temperature, the constant temperature time and the pressure of an inner cavity space of the heat treatment device, and enabling the atmosphere in the cavity space of the heat treatment device to be inert atmosphere; and measuring the thickness and uniformity of the oxide layer in the silicon-based material after heat treatment so as to judge the oxygen leakage degree in the RTO process. The measuring method provided by the invention is simple in process, can accurately measure the oxygen leakage degree of the silicon-based material in the RTO process, is high in efficiency, can accurately measure the oxygen leakage degree and uniformity of the silicon-based material in a high-temperature environment, and can realize the sealing detection of the cavity space in the device in the RTO process.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to a method for measuring oxygen leakage during RTO of silicon-based materials and an application thereof. Background Art

[0002] In the semiconductor manufacturing process, the thermal oxidation treatment (Rapid Thermal Oxidation, RTO) of silicon carbide and silicon-based materials is a key step, so the sealing of the heat treatment device used in this step is crucial. However, the traditional method of measuring oxygen content (oxygen leakage) has some defects, such as insufficient measurement accuracy, slow measurement speed, and inability to accurately measure in high temperature environments.

[0003] Therefore, it is urgent to design a measurement method to improve the measurement accuracy and efficiency of oxygen leakage during the RTO process and achieve accurate measurement under high temperature conditions. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for measuring the oxygen leakage degree of silicon-based materials during the RTO process and its application. The measurement method provided by the present invention is not only simple in process, but also can accurately measure the oxygen leakage degree of silicon-based materials during the RTO process, with high efficiency, and can accurately measure the oxygen leakage degree and uniformity of silicon-based materials in a high temperature environment, and can realize the sealing detection of the cavity space in the device during the RTO process.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for measuring oxygen leakage during RTO of a silicon-based material, the method comprising the following steps:

[0007] The silicon-based material is placed in a heat treatment device, and then the temperature, constant temperature time and pressure of the inner cavity space of the heat treatment device are set, and the atmosphere in the cavity space of the heat treatment device is made to be an inert atmosphere.

[0008] Measure the thickness and uniformity of the oxide layer in the heat-treated silicon-based material to determine the degree of oxygen leakage during the RTO process.

[0009] The measurement method provided by the present invention is not only simple in process, but also can accurately measure the oxygen leakage degree of silicon-based materials during the RTO process with high efficiency. Moreover, it can accurately measure the oxygen leakage degree and uniformity of silicon-based materials in a high temperature environment, and can realize the sealing detection of the cavity space inside the device during the RTO process.

[0010] It should be noted that RTO refers to Rapid Thermal Oxidation. This step has some defects, such as insufficient measurement accuracy, slow measurement speed, and inability to perform accurate measurement in high temperature environments.

[0011] As a preferred technical solution of the present invention, the silicon-based material includes any one of silicon carbide, porous silicon or microcrystalline silicon, or a combination of at least two of them.

[0012] As a preferred technical solution of the present invention, the temperature range of the heat treatment device is 800-900°C, for example, it can be 800°C, 850°C or 900°C.

[0013] The present invention performs an RTO process on a heat treatment device at a temperature of 800-900°C to determine the degree of oxygen leakage during the RTO process, which can fully realize thermal oxidation treatment of silicon-based materials. It is difficult to accurately determine the degree of oxygen leakage during the RTO process when the temperature is too low or too high.

[0014] As a preferred technical solution of the present invention, the constant temperature time of the heat treatment device is 5 to 10 minutes, for example, it can be 5 minutes, 7 minutes or 10 minutes.

[0015] As a preferred technical solution of the present invention, the pressure of the inner cavity space of the heat treatment device is 50-150 kPa, for example, it can be 50 kPa, 100 kPa or 150 kPa.

[0016] In the present invention, the pressure of the inner cavity space of the heat treatment device is limited to 50-150 kPa, which helps to more accurately determine the degree of oxygen leakage during the RTO process.

[0017] As a preferred technical solution of the present invention, the gas in the inert atmosphere includes an inert gas, and the inert gas includes any one of nitrogen, argon, helium, xenon, neon or krypton, or a combination of at least two of them.

[0018] In the present invention, the above-mentioned inert gas is used to replace oxygen for the RTO process, which is an important condition to help measure the degree of oxygen leakage during the RTO process of silicon-based materials. Through this substitution, if the heat treatment device leaks oxygen during the RTO process, an oxide layer will inevitably appear on the surface of the silicon-based material due to the infiltration of external oxygen.

[0019] Preferably, the concentration of the inert gas is greater than 99%, for example, it may be 99.2%, 99.4%, 99.6% or 99.9%.

[0020] As a preferred technical solution of the present invention, the equipment for measuring the thickness and uniformity of the oxide layer in the silicon-based material includes an optical measuring device, preferably a non-contact optical measuring device.

[0021] Preferably, the thickness measurement accuracy of the non-contact optical measuring device is -0.1 to 0.1 μm, for example, it may be -0.1 μm, -0.05 μm, 0 μm, 0.05 μm or 0.1 μm.

[0022] The non-contact optical measuring device provided by the present invention has high precision and fast measuring speed and can perform accurate measurement in a high temperature environment.

[0023] As a preferred technical solution of the present invention, after determining the degree of oxygen leakage during the RTO process, steps of data processing and RTO parameter optimization are further performed.

[0024] As a preferred technical solution of the present invention, the measuring method comprises the following steps:

[0025] (1) Placing the silicon-based material in a heat treatment device, then setting the temperature of the heat treatment device to 800-900° C., the constant temperature time to 5-10 min, the pressure of the inner cavity space to 50-150 kPa, and making the atmosphere in the cavity space of the heat treatment device a nitrogen atmosphere.

[0026] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0027] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0028] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0029] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0030] In a second aspect, the present invention provides an application of the measurement method as described in the first aspect in the field of semiconductor manufacturing.

[0031] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The measurement method provided by the present invention is not only simple in process, but also can accurately measure the oxygen leakage degree of silicon-based materials during the RTO process with high efficiency. Moreover, it can accurately measure the oxygen leakage degree and uniformity of silicon-based materials in a high temperature environment, and can realize the sealing detection of the cavity space inside the device during the RTO process. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart for measuring the oxygen leakage level during the RTO process of silicon-based materials provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0036] Example 1

[0037] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and its flow chart is as follows: Figure 1 As shown, the measuring method comprises the following steps:

[0038] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 850° C., the constant temperature time is 7 minutes, the pressure of the inner cavity space is 100 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere, and the concentration of the nitrogen is 99.9%.

[0039] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0040] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0041] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0042] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0043] Example 2

[0044] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0045] (1) Porous silicon is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 820°C, the constant temperature time is 8 minutes, the pressure of the inner cavity space is 80 kPa, and the atmosphere in the cavity space of the heat treatment device is an argon atmosphere, and the concentration of the argon is 99.9%.

[0046] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0047] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0048] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0049] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0050] Example 3

[0051] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0052] (1) Microcrystalline silicon is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 870°C, the constant temperature time is 6 minutes, the pressure of the inner cavity space is 120 kPa, and the atmosphere in the cavity space of the heat treatment device is a helium atmosphere, and the concentration of the helium is 99.9%.

[0053] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0054] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0055] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0056] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0057] Example 4

[0058] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0059] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 800° C., the constant temperature time is 10 min, the pressure of the inner cavity space is 50 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere, and the concentration of the nitrogen is 99.9%.

[0060] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0061] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0062] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0063] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0064] Example 5

[0065] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0066] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 900° C., the constant temperature time is 5 minutes, the pressure of the inner cavity space is 150 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere, and the concentration of the nitrogen is 99.9%.

[0067] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0068] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0069] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0070] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0071] Example 6

[0072] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0073] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 600° C., the constant temperature time is 7 minutes, the pressure of the inner cavity space is 100 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere.

[0074] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0075] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0076] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0077] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0078] Example 7

[0079] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0080] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 1000° C., the constant temperature time is 7 minutes, the pressure of the inner cavity space is 100 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere.

[0081] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0082] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0083] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0084] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0085] Example 8

[0086] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0087] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 700° C., the constant temperature time is 3 minutes, the pressure of the inner cavity space is 100 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere.

[0088] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0089] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0090] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0091] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0092] Example 9

[0093] This embodiment provides a method for measuring oxygen leakage during the RTO process of silicon-based materials, and the method comprises the following steps:

[0094] (1) Silicon carbide is placed in a heat treatment device, and then the temperature of the heat treatment device is set to 700° C., the constant temperature time is 15 min, the pressure of the inner cavity space is 100 kPa, and the atmosphere in the cavity space of the heat treatment device is a nitrogen atmosphere.

[0095] (2) Starting a heat treatment device to perform heat treatment on the silicon-based material.

[0096] (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, which is used to determine the degree of oxygen leakage during the RTO process.

[0097] (4) Analyzing the data measured in step (3) using a data processing system to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the set parameters in the RTO process according to the distribution diagram, wherein the set parameters include the temperature, constant temperature time and pressure of the heat treatment.

[0098] (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

[0099] Comparative Example 1

[0100] The difference between this comparative example and Example 1 is that the atmosphere in the cavity space of the heat treatment device is a carbon dioxide atmosphere.

[0101] The rest of the preparation methods and parameters were the same as those in Example 1.

[0102] In summary, the measurement method provided by the present invention can accurately measure the oxygen leakage degree of silicon-based materials during the RTO process with high measurement accuracy and efficiency, and can accurately measure the oxygen leakage degree and uniformity of silicon-based materials in a high temperature environment, and can realize the sealing detection of the cavity space inside the device during the RTO process.

[0103] It can be seen from Example 1 and Examples 6-7 that when setting the parameters of the heat treatment device, a temperature that is too low or too high will lead to insufficient measurement accuracy, slow measurement speed, and inability to obtain accurate measurement results.

[0104] It can be seen from Example 1 and Examples 8-9 that when setting the parameters of the heat treatment device, a constant temperature time that is too short or too long will lead to insufficient measurement accuracy and an inability to obtain accurate measurement results.

[0105] It can be seen from Example 1 and Comparative Example 1 that if the atmosphere in the chamber space of the heat treatment device is a carbon dioxide atmosphere, it is difficult to obtain accurate measurement results.

[0106] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for measuring oxygen leakage during RTO of silicon-based materials, characterized in that: The measuring method comprises the following steps: Placing the silicon-based material in a heat treatment device, then setting the temperature, constant temperature time and pressure of the inner cavity space of the heat treatment device, and making the atmosphere in the cavity space of the heat treatment device an inert atmosphere; Measure the thickness and uniformity of the oxide layer in heat-treated silicon-based materials to determine the degree of oxygen leakage during the RTO process.

2. The measuring method according to claim 1, characterized in that: The silicon-based material includes any one of silicon carbide, porous silicon or microcrystalline silicon, or a combination of at least two of them.

3. The measuring method according to claim 1, characterized in that: The temperature range of the heat treatment device is 800-900°C.

4. The measuring method according to claim 1, characterized in that: The constant temperature time of the heat treatment device is 5 to 10 minutes.

5. The measuring method according to claim 1, characterized in that: The relative pressure of the inner cavity space of the heat treatment device is 50-150 kPa.

6. The measuring method according to claim 1, characterized in that: The gas in the inert atmosphere includes an inert gas, and the inert gas includes any one or a combination of at least two of nitrogen, argon, helium, xenon, neon or krypton; The concentration of the inert gas is >99%.

7. The measuring method according to claim 1, characterized in that: The apparatus for measuring the thickness and uniformity of the oxide layer in the silicon-based material includes an optical measurement device; The thickness measurement accuracy of the non-contact optical measuring device is -0.1 to 0.1 μm.

8. The measuring method according to claim 1, characterized in that: After determining the degree of oxygen leakage during the RTO process, steps of data processing and RTO parameter optimization are also performed.

9. The measuring method according to claim 1, characterized in that: The measuring method comprises the following steps: (1) placing the silicon-based material in a heat treatment device, then setting the temperature of the heat treatment device to 800-900° C., the constant temperature time to 5-10 min, the pressure of the inner cavity space to 50-150 kPa, and making the atmosphere in the cavity space of the heat treatment device a nitrogen atmosphere; (2) starting a heat treatment device to perform heat treatment on the silicon-based material; (3) Using a non-contact optical measuring device to measure the silicon-based material after heat treatment to measure whether there is an oxide layer on the surface of the silicon-based material and the uniformity of the oxide layer, so as to determine the degree of oxygen leakage during the RTO process; (4) using a data processing system to analyze the data measured in step (3) to obtain a distribution diagram of the thickness and uniformity of the oxide layer, and then adjusting the setting parameters in the RTO process according to the distribution diagram, wherein the setting parameters include the temperature, constant temperature time and pressure of the heat treatment; (5) Repeat steps (2) to (4) until no oxide layer is detected on the surface of the silicon-based material.

10. Application of the measurement method according to any one of claims 1 to 9 in the field of semiconductor manufacturing.

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