Cleaning method of deposition cavity
By reducing molybdenum trioxide on the inner surface of the deposition cavity and combining the technology of purge gas and pump, the problem of falling off the deposits on the inner surface of the deposition cavity to form micro particles is solved, and the quality and yield of thin film deposition are significantly improved.
Patent Information
- Application Number
- CN202510049211.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art is difficult to thoroughly clean the deposition cavity, causing the deposit to fall off and form microparticles, affecting the quality and yield of thin film deposition.
Monohydrogen plasma is used to reduce the molybdenum trioxide attached to the inner surface of the deposition cavity, convert it into molybdenum deposits and water gas, and remove the micro particles and molybdenum precursors in the deposition cavity through a purge gas and a pump.
Effectively remove molybdenum trioxide and microparticles on the inner surface of the deposition cavity, significantly reduce the number of microparticles, and improve the quality and yield of thin film deposition.
Smart Images
Figure CN119876903A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a cleaning method for a deposition chamber, which can effectively reduce particles in the deposition chamber to improve the quality and yield of subsequent thin film deposition processes. Background Art
[0002] Thin film deposition is a commonly used process technology in semiconductor processes, mainly used to form a thin film on the surface of a substrate, including, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD) and atomic layer deposition (ALD).
[0003] Taking atomic layer deposition (ALD) as an example, most ALD processes usually use at least two precursor gases. The two precursor gases are sequentially transported into the deposition chamber and react with the surface of the substrate or the precursor on the surface of the substrate to gradually deposit a thin film on the surface of the substrate.
[0004] During the deposition process, in addition to being deposited on the surface of the substrate, the film will also form a deposit on the inner surface of the deposition chamber. After the deposition chamber has been used for a period of time, the thickness of the deposit on the inner surface of the chamber will gradually increase. Generally speaking, the structure of the deposit on the inner surface of the deposition chamber is relatively loose. For example, the deposit on the inner surface of the deposition chamber is a metal oxide film, which may fall from the inner surface of the chamber and pollute the interior of the chamber, such as forming particles in the chamber. The presence of particles can cause the thickness of the deposited film to be uneven or increase the impurity content of the film, thereby affecting the electrical or optical properties of the electronic components subsequently manufactured.
[0005] In order to solve the above problems, the industry generally delivers precursor gas or inert gas into the deposition chamber before the deposition process to remove the particles inside the deposition chamber. However, the above steps can only preliminarily clean the internal space of the deposition chamber and remove the particles located in the internal space of the deposition chamber, but cannot truly clean the deposition chamber, for example, it cannot remove the sediment attached to the inner surface of the deposition chamber. If the sediment on the inner surface of the deposition chamber falls off during the deposition process, it will still cause contamination to the internal space of the deposition chamber and the substrate, thereby causing uneven thickness of the film deposited on the surface of the substrate or increased impurity content. Summary of the invention
[0006] In order to solve the problems described in the prior art, the present invention provides a cleaning method for a deposition chamber, which can be used to remove sediments attached to the inner surface of the deposition chamber to prevent the sediments from falling off the inner surface of the deposition chamber and contaminating the internal space of the deposition chamber or the substrate.
[0007] One object of the present invention is to provide a method for cleaning a deposition chamber, which mainly uses a hydrogen plasma to reduce molybdenum trioxide attached to the inner surface of the deposition chamber, and reduces the molybdenum trioxide to molybdenum deposits and water vapor. Then, a purge gas is delivered into the deposition chamber, and the excess molybdenum precursor and water vapor in the deposition chamber are pumped out by a vacuum pump.
[0008] The cleaning method of the deposition chamber described in the present invention can effectively remove molybdenum trioxide attached to the inner surface of the deposition chamber, and remove the microparticles and molybdenum precursors inside the deposition chamber, which can greatly reduce the number of microparticles in the deposition chamber, which is beneficial to improving the quality and yield of subsequent thin film deposition.
[0009] One object of the present invention is to provide a method for cleaning a deposition chamber, which is particularly suitable for cleaning a deposition chamber used for depositing a molybdenum metal film. The deposition chamber can be used to perform a deposition process on a substrate inside to form a molybdenum metal film on the surface of the substrate, and the substrate that has completed the deposition process is taken out of the deposition chamber. Then, according to the time and number of times the deposition chamber performs film deposition, it can be determined whether to clean the deposition chamber to maintain the number of microparticles inside the deposition chamber at a very small amount.
[0010] In order to achieve the above-mentioned objectives, the present invention proposes a method for cleaning a deposition chamber, comprising: delivering a purge gas into a deposition chamber and pumping out the gas inside the deposition chamber through an exhaust pump; reducing a deposit attached to the inner surface of the deposition chamber through a hydrogen plasma, wherein the deposit includes molybdenum trioxide; and delivering a purge gas into the deposition chamber and pumping out the gas inside the deposition chamber through an exhaust pump.
[0011] The present invention proposes another method for cleaning a deposition chamber, comprising: delivering a purge gas into a deposition chamber, and extracting the gas inside the deposition chamber through an exhaust pump; reducing molybdenum trioxide attached to the inner surface of the deposition chamber through a hydrogen plasma, and reducing the molybdenum trioxide to water vapor and molybdenum, wherein the molybdenum includes molybdenum deposits located on the inner surface of the deposition chamber, and molybdenum particles located inside the deposition chamber; and delivering a purge gas into the deposition chamber, and extracting the molybdenum particles inside the deposition chamber through an exhaust pump.
[0012] In one embodiment of the cleaning method of the deposition chamber, the following steps are included: forming a molybdenum metal film on the inner surface of the deposition chamber.
[0013] In one embodiment of the deposition chamber cleaning method, hydrogen plasma reacts with molybdenum trioxide on the inner surface of the deposition chamber to generate molybdenum and water vapor.
[0014] In one embodiment of the cleaning method for the deposition chamber, hydrogen plasma reacts with molybdenum trioxide on the inner surface of the deposition chamber to produce molybdenum particles and water vapor. When the hydrogen plasma reduces the deposits attached to the inner surface of the deposition chamber, a purge gas is transported into the deposition chamber, and the molybdenum particles and water vapor inside the deposition chamber are pumped out by a vacuum pump.
[0015] In one embodiment of the cleaning method for a deposition chamber, the hydrogen plasma is generated by a remote plasma source, a capacitively coupled plasma source, an inductively coupled plasma source, or a microwave plasma source.
[0016] In one embodiment of the cleaning method of the deposition chamber, an exhaust pump is used to extract the gas and molybdenum precursor inside the deposition chamber, and the molybdenum precursor includes molybdenum pentachloride, molybdenum dioxide dichloride, molybdenum oxytetrachloride, molybdenum hexacarbonyl, bis(tertiary butylimino)bis(dimethylamino)molybdenum or bis(ethylbenzene)molybdenum.
[0017] In one embodiment of the deposition chamber cleaning method, the following steps are included: transporting a substrate into the deposition chamber and forming a molybdenum metal film on the surface of the substrate; transporting the substrate to the outside of the deposition chamber; and determining whether to clean the deposition chamber.
[0018] In one embodiment of the deposition chamber cleaning method, whether to clean the deposition chamber is determined based on the usage time of the deposition chamber.
[0019] In one embodiment of the cleaning method of the deposition chamber, the steps include: forming a molybdenum metal film on the inner surface of the deposition chamber, and covering the molybdenum deposits attached to the inner surface of the deposition chamber with the molybdenum metal film.
[0020] The cleaning method of the deposition chamber described in the present invention has the following advantages: it can effectively remove molybdenum trioxide attached to the inner surface of the deposition chamber, and remove molybdenum particles and molybdenum precursors inside the deposition chamber, which is beneficial to improving the quality and yield of subsequent thin film deposition. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 A flow chart showing the steps of an embodiment of a thin film deposition and cleaning method of the present invention; Figure 2 FIG. 1 is a flow chart of steps of an embodiment of a method for cleaning a deposition chamber of the present invention. DETAILED DESCRIPTION
[0022] Figure 1 FIG. 1 is a flow chart of the steps of a thin film deposition and cleaning method according to an embodiment of the present invention. Figure 2The present invention is a flow chart of steps of an embodiment of a cleaning method for a deposition chamber. As shown in the figure, when a thin film deposition process is performed, at least one substrate can be transported into a deposition chamber, and a thin film deposition process is performed on the substrate in the deposition chamber to form a metal film on the surface of the substrate, as shown in step 11.
[0023] Depending on the application field, the substrate described in the present invention can be silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other material, for example, the substrate includes titanium nitride (TiN), titanium silicide (TiSi), tungsten-titanium silicide alloy, clean silicon (Si), boron-doped silicon germanium (SiGeB), clean silicon phosphide (SiP), etc.
[0024] In one embodiment of the present invention, the deposition chamber may be a chemical vapor deposition chamber, a physical vapor deposition chamber or an atomic layer deposition chamber. For the convenience of description, the following description is made by taking the atomic layer deposition chamber to deposit a molybdenum metal film on the surface of a substrate as an example.
[0025] When a molybdenum metal film is deposited on a substrate surface by atomic layer deposition, a molybdenum precursor is delivered into a deposition chamber. For example, the molybdenum precursor includes molybdenum pentachloride (MoCl5), molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxychloride (MoOCl4), molybdenum hexacarbonyl, bis(tertiary butylimino)bis(dimethylamino)molybdenum or bis(ethylphenyl)molybdenum.
[0026] In one embodiment of the present invention, molybdenum dioxide dichloride (MoO2Cl2) can be used in combination with hydrogen plasma to deposit a molybdenum metal film on the surface of a substrate. For example, molybdenum dioxide dichloride and hydrogen plasma can be sequentially transferred to the surface of the substrate. After multiple cycles, a molybdenum metal film of a certain thickness can be gradually formed on the surface of the substrate, as shown in the following reaction formula: MoO2Cl2+H2 (Plasma)→Mo (solid)+HCL (gas) +H2O (gas) Then, the substrate after the deposition process is completed can be taken out of the deposition chamber, wherein the surface of the substrate has a molybdenum metal film, as shown in step 13 .
[0027] During the deposition process, part of the precursor molybdenum dichloride (MoO2Cl2) may not react completely and remain inside or on the inner surface of the deposition chamber, and may gradually form a molybdenum trioxide (MoO3) film on the inner surface of the deposition chamber. The structure of molybdenum trioxide is loose, and the adhesion between it and the inner surface of the deposition chamber is low. Therefore, molybdenum trioxide may peel off from the inner surface of the deposition chamber and form particles inside the deposition chamber. For example, the number of particles in the deposition chamber may be greater than 10,000. When the number of particles is too large, it may cause defects in the molybdenum metal film deposited on the surface of the substrate and reduce the yield of the thin film process, such as the formation of wafer defects.
[0028] In order to reduce the number of particles and reduce the impact on the deposited film on the substrate surface, a purge gas is usually delivered into the deposition chamber before the deposition step, and a vacuum pump is used to extract the gas and particles in the deposition chamber to remove the particles suspended in the deposition chamber.
[0029] After the above cleaning steps are completed, a new substrate may be transported into the deposition chamber, and a metal film may be deposited on the surface of the substrate.
[0030] However, in actual applications, the purge gas can only be used to remove the microparticles suspended in the deposition chamber, and cannot remove the deposits attached to the inner surface of the deposition chamber. After the purge gas is stopped from being delivered to the deposition chamber, if the loosely structured deposits fall off from the inner surface of the deposition chamber, microparticles will still be formed inside the deposition chamber, affecting the quality of the thin film subsequently deposited on the substrate surface, and further forming defects on the wafer surface.
[0031] In order to solve the above-mentioned problem, the present invention proposes a novel deposition chamber cleaning method, which further determines whether the deposition chamber needs to be cleaned, as shown in step 15 .
[0032] Specifically, the number of times or time of thin film deposition in the deposition chamber can be used to determine whether the deposition chamber needs to be cleaned. For example, a preset value can be calculated based on the relationship between the cumulative number of thin film depositions and the particles or sediments in the deposition chamber.
[0033] When the number of times or time for the deposition chamber to perform thin film deposition is less than a preset value, it means that the deposition chamber can continue to perform thin film deposition on the substrate, and step 11 to step 13 are performed.
[0034] On the contrary, when the number of times or time of thin film deposition in the deposition chamber is greater than a preset value, it indicates that a certain thickness of deposits has accumulated on the inner surface of the deposition chamber, for example, the deposits are molybdenum trioxide, and a deposition chamber cleaning step is required, and step 20 is executed to perform the deposition chamber cleaning method. In different embodiments, the number of microparticles inside the deposition chamber can also be directly measured. When the number of microparticles is greater than a threshold value, it indicates that the deposition chamber needs to be cleaned, and step 20 is executed.
[0035] Detailed cleaning method of deposition chamber is as follows Figure 2 As shown, first, a purge gas is delivered into the deposition chamber, and a vacuum pump is used to extract the gas in the deposition chamber to remove the particles and molybdenum precursor suspended in the deposition chamber, as shown in step 21.
[0036] In practical applications, the purge gas may be an inert gas or a gas that does not affect subsequent deposition steps, for example, the purge gas may be argon or nitrogen, etc. When the deposition chamber is an atomic layer deposition chamber for depositing a molybdenum metal film on a substrate surface, the particles in the deposition chamber may include molybdenum trioxide or a molybdenum precursor, for example, the molybdenum precursor includes molybdenum pentachloride (MoCl5), molybdenum dichloride (MoO2Cl2), molybdenum oxytetrachloride (MoOCl4), molybdenum hexacarbonyl, bis(tertiary butylimino)bis(dimethylamino)molybdenum or bis(ethylbenzene)molybdenum, etc.
[0037] Then, the deposit on the inner surface of the deposition chamber is reduced by plasma, as shown in step 23. In one embodiment of the present invention, the deposit on the inner surface of the deposition chamber may be molybdenum trioxide (MoO3), and the molybdenum trioxide may be reduced by hydrogen plasma, and the reaction formula is as follows: 2MoO3 (solid) + H2 (Plasma) → 2Mo (solid) + 2H2O(gas) Specifically, hydrogen plasma reacts with molybdenum trioxide attached to the inner surface of the deposition chamber and reduces the molybdenum trioxide into molybdenum and water vapor. For example, the molybdenum produced by the reduction may adhere to the inner surface of the deposition chamber to form molybdenum deposits, or fall into the deposition chamber to form molybdenum particles.
[0038] In practical applications, hydrogen plasma can be generated by a remote plasma source, a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, or a microwave plasma source.
[0039] In the process of removing the deposits attached to the inner surface of the deposition chamber by hydrogen plasma, the purge gas can be delivered to the deposition chamber, and the pollutants and gases in the deposition chamber can be pumped out by the vacuum pump to preliminarily remove the pollutants in the deposition chamber. For example, the hydrogen plasma at the far end can be delivered to the inside of the deposition chamber or the hydrogen plasma can be formed inside the deposition chamber. After the deposition chamber is cleaned by hydrogen plasma for a preset time, the purge gas is delivered to the deposition chamber, and the microparticles, pollutants and / or gases in the deposition chamber are pumped out by the vacuum pump. The above steps can be repeated for multiple times.
[0040] After the deposits on the inner surface of the deposition chamber are removed by hydrogen plasma, a purge gas can be delivered to the deposition chamber, and a vacuum pump can be used to extract the gas in the deposition chamber to remove the particles and water vapor suspended in the deposition chamber. For example, the particles may include molybdenum particles and molybdenum precursors, as shown in step 25.
[0041] The above steps 21 to 25 can be repeated to remove most of the molybdenum trioxide attached to the inner surface of the deposition chamber. In practical applications, the number of times to repeat steps 21 to 25 can be set, for example, the number of times to repeat steps 21 to 25 can be calculated based on the use time of the deposition chamber or the number of depositions.
[0042] In another embodiment of the present invention, the number of times step 21, step 23 and step 25 are performed can be preset before cleaning the deposition chamber. Specifically, the number of cycles of delivering the purge gas to the deposition chamber and extracting the gas in the deposition chamber by the vacuum pump can be set to remove the microparticles suspended in the deposition chamber. For example, after repeatedly performing the above steps 21 to 25, the number of microparticles in the deposition chamber can be reduced to less than 300. The method for cleaning the deposition chamber described in the present invention can effectively control the number of microparticles in the deposition chamber and improve the quality of the molybdenum metal film deposited on the surface of the substrate.
[0043] After removing the deposits of molybdenum trioxide attached to the inner surface of the deposition chamber and removing the particles inside the deposition chamber, a molybdenum metal film can be further formed on the inner surface of the deposition chamber. For example, when the substrate is not transported to the inside of the deposition chamber, a molybdenum metal film is deposited on the inner surface of the deposition substrate by using molybdenum dichloride (MoO2Cl2) in combination with hydrogen plasma. The structure of the molybdenum metal film deposited on the inner surface of the deposition chamber is tighter than that of molybdenum oxide, and has a higher adhesion to the inner surface of the deposition chamber, and is less likely to fall off from the inner surface of the deposition chamber.
[0044] In addition, the molybdenum metal film formed on the inner surface of the deposition chamber can be used to cover the sediment remaining on the inner surface of the deposition chamber to prevent the sediment that has not been completely removed from falling from the inner surface of the deposition chamber and contaminating the internal space of the deposition chamber.
[0045] Specifically, the molybdenum produced after hydrogen plasma reduction of molybdenum trioxide may include: molybdenum deposits attached to the inner surface of the deposition chamber, or molybdenum particles located inside the deposition chamber. The vacuum pump can be used to extract the molybdenum particles inside the deposition chamber, but it cannot extract the molybdenum deposits attached to the inner surface of the deposition chamber. After the above-mentioned cleaning steps, the molybdenum deposits on the inner surface of the deposition chamber may still fall into the interior of the deposition chamber, forming molybdenum particles inside the deposition chamber and contaminating the deposition chamber and the substrate. The molybdenum metal film formed on the inner surface of the deposition chamber can be used to cover the molybdenum deposits remaining on the inner surface of the deposition chamber, and prevent the molybdenum deposits from falling from the deposition chamber and forming molybdenum particles inside the deposition chamber.
[0046] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. That is, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the patent application scope of the present invention should be included in the patent application scope of the present invention.
Claims
1. A method for cleaning a deposition chamber, characterized in that: include: A purge gas is delivered into a deposition chamber, and the gas in the deposition chamber is pumped out by a pump; Reducing a deposit attached to the inner surface of the deposition chamber by a hydrogen plasma, wherein the deposit comprises molybdenum trioxide; and The purge gas is delivered to the interior of the deposition chamber, and the gas inside the deposition chamber is pumped out by the pump.
2. The method for cleaning a deposition chamber according to claim 1, wherein: The following steps are involved: A molybdenum metal film is formed on the inner surface of the deposition chamber.
3. The method for cleaning a deposition chamber according to claim 1, wherein: The hydrogen plasma reacts with the molybdenum trioxide on the inner surface of the deposition chamber and generates molybdenum and water gas.
4. The method for cleaning a deposition chamber according to claim 1, wherein: The hydrogen plasma reacts with the molybdenum trioxide on the inner surface of the deposition chamber to generate molybdenum particles and water vapor. When the hydrogen plasma reduces the deposits attached to the inner surface of the deposition chamber, the purge gas is transported to the interior of the deposition chamber, and the molybdenum particles and water vapor inside the deposition chamber are pumped out by the vacuum pump.
5. The method for cleaning a deposition chamber according to claim 1, wherein: The hydrogen plasma is generated by a remote plasma source, a capacitively coupled plasma source, an inductively coupled plasma source or a microwave plasma source.
6. The method for cleaning a deposition chamber as described in claim 1, wherein the vacuum pump is used to extract the gas and molybdenum precursor in the deposition chamber, and the molybdenum precursor includes molybdenum pentachloride, molybdenum dioxide dichloride, molybdenum oxytetrachloride, molybdenum hexacarbonyl, bis(tertiary butylimino)bis(dimethylamino)molybdenum or bis(ethylphenyl)molybdenum.
7. The method for cleaning a deposition chamber according to claim 1, wherein: The following steps are involved: Transporting a substrate into the deposition chamber and forming a molybdenum metal film on the surface of the substrate; transporting the substrate to the outside of the deposition chamber; and Determine whether to clean the deposition chamber.
8. The method for cleaning a deposition chamber according to claim 7, wherein: The following steps are involved: Whether to clean the deposition chamber is determined according to the use time of the deposition chamber.
9. A method for cleaning a deposition chamber, characterized in that: include: A purge gas is delivered into a deposition chamber, and the gas in the deposition chamber is pumped out by a pump; Reducing molybdenum trioxide attached to the inner surface of the deposition chamber by a hydrogen plasma, and reducing the molybdenum trioxide to water vapor and molybdenum, wherein the molybdenum includes a deposit of molybdenum attached to the inner surface of the deposition chamber and molybdenum particles located inside the deposition chamber; and The purge gas is delivered to the interior of the deposition chamber, and the molybdenum particles in the deposition chamber are pumped out by the pump.
10. The method for cleaning a deposition chamber according to claim 9, wherein: The following steps are involved: A molybdenum metal film is formed on the inner surface of the deposition chamber, and the molybdenum deposit attached to the inner surface of the deposition chamber is covered with the molybdenum metal film.