Epitaxial reaction chamber

Abstract

The present invention provides an epitaxial reaction chamber, which includes an upper dome, a lower dome, a shielding member, and a chamber sidewall disposed between the upper dome and the lower dome. A first gas inlet for introducing process gas and a first gas outlet for discharging process gas are provided on the chamber sidewall. The shielding member is disposed opposite to the upper dome and is located above the first gas outlet, and is used to block the process gas from contacting the upper dome. The epitaxial reaction chamber provided by the present invention can improve the process quality, extend the maintenance cycle and service life of the reaction chamber, and improve the production capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular, to an epitaxial reaction chamber. Background Art

[0002] The chemical vapor deposition (CVD) silicon epitaxy process uses trichlorosilane (SiHCl3, TCS) as a silicon source to react with hydrogen at a temperature above 1100 °C to grow a certain thickness of single crystal silicon with the same lattice arrangement as the original silicon substrate on the surface of the silicon substrate.

[0003] Currently, the monolithic silicon epitaxy equipment generally forms a sealed chamber by an upper dome, a lower dome and the side wall of the middle reaction chamber. A pedestal is arranged in the chamber, and a heating lamp group is arranged outside the chamber. During the silicon epitaxy process, the silicon substrate is placed on the pedestal, and the reaction gas is introduced between the upper dome and the pedestal. The heating lamp group is used to heat the chamber to make the temperature in the chamber reach the required process temperature, so as to grow an epitaxial layer on the surface of the silicon substrate. Generally, an air cooling system is also arranged outside the chamber to prevent the high temperature during the silicon epitaxy process from causing the temperature of the external environment of the chamber to be too high and causing harm to the external components and personnel of the chamber.

[0004] During the silicon epitaxy process, the by-products generated by the silicon source and hydrogen will also adhere and deposit on the inner wall of the chamber. Therefore, after epitaxy, hydrogen chloride gas is required to etch and remove the by-products on the inner wall of the chamber. However, due to the existence of the air cooling system outside the upper dome, the temperature of the upper dome is only about 620 °C. Under low temperature conditions, the etching effect of hydrogen chloride gas is poor. Therefore, usually after being used for a period of time, there will be yellow by-products on the inner wall of the upper dome, resulting in poor light transmittance of the upper dome, affecting the reading of the infrared thermometer, and due to the uneven distribution of the by-products, it will also cause the phenomenon of uneven temperature of the pedestal. In addition, if these by-products peel off, it will also cause particle problems. These factors will all affect the quality of the epitaxial wafer. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art, and provides an epitaxial reaction chamber, which can improve the process quality, extend the maintenance cycle and service life of the epitaxial reaction chamber, and improve the production capacity.

[0006] To achieve the purpose of the present invention, an epitaxial reaction chamber is provided, which includes an upper dome, a lower dome and a chamber side wall arranged between the upper dome and the lower dome. A first air inlet for introducing process gas and a first air outlet for discharging the process gas are arranged on the chamber side wall. The epitaxial reaction chamber further includes a shielding member, which is arranged opposite to the upper dome and above the first air outlet, and is used to block the process gas from contacting the upper dome.

[0007] Preferably, the shielding member is parallel to the upper dome, and the orthographic projection of the shielding member at least coincides with the part of the upper dome projected in the epitaxial reaction chamber.

[0008] Preferably, an annular groove is provided in the chamber side wall, the shielding member is arranged in the annular groove, and the chamber side wall, the upper dome and the shielding member form a barrier chamber.

[0009] Preferably, a second gas inlet and a second gas outlet are provided in the chamber side wall. Among them, the second gas inlet is located between the upper dome and the shielding member and is used to introduce a barrier gas into the barrier chamber; the second gas outlet is used to discharge the barrier gas in the barrier chamber.

[0010] Preferably, the process gas includes hydrogen, and the barrier gas includes hydrogen.

[0011] Preferably, the epitaxial reaction chamber further includes an intake assembly provided at the first gas inlet to supply the process gas, and an exhaust assembly provided at the first gas outlet for discharging the process gas, and the second gas outlet is communicated with the first gas outlet through an exhaust passage.

[0012] Preferably, the shielding member is hermetically connected to the chamber side wall.

[0013] Preferably, the barrier chamber is filled with an inert gas.

[0014] Preferably, the shielding member is made of transparent quartz material and has a thickness of 2 mm - 5 mm.

[0015] Preferably, the vertical distance between the shielding member and the upper dome ranges from 5 mm to 10 mm.

[0016] The present invention has the following beneficial effects:

[0017] The epitaxial reaction chamber provided by the present invention uses a shielding member that is disposed opposite to the upper dome and above the first air outlet to block the process gas from contacting the upper dome, so that the reaction by-products generated by the process gas during the process do not deposit on the upper dome, but deposit on the shielding member. Since the shielding member is disposed inside the epitaxial reaction chamber and is less affected by the air-cooling system outside the epitaxial reaction chamber, the reaction by-products deposited on the shielding member can be easily etched away, thereby avoiding the deposition of reaction by-products on the shielding member, reducing the probability of reaction by-products falling on the wafer, improving the process quality, reducing the erosion of the reaction by-products on the upper dome and the shielding member, and reducing the probability of reaction by-products falling on other components inside the epitaxial reaction chamber, reducing the erosion of the reaction by-products on other components, thereby extending the maintenance cycle and service life of the epitaxial reaction chamber, and improving the production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of an epitaxial reaction chamber provided by the first embodiment of the present invention;

[0019] Figure 2 is a schematic structural diagram of the upper dome and the shielding member of the epitaxial reaction chamber provided by the second embodiment of the present invention;

[0020] Description of the reference numerals:

[0021] 1 - pedestal; 21 - upper dome; 211 - convex portion; 22 - shielding member; 3 - lower dome; 4 - chamber side wall; 41 - annular groove; 42 - barrier chamber; 51 - first inlet; 52 - first outlet; 61 - second inlet; 62 - second outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To enable those skilled in the art to better understand the technical solutions of the present invention, the reaction chamber provided by the present invention will be described in detail below with reference to the drawings.

[0023] As Figure 1 and Figure 2 shown, this embodiment provides an epitaxial reaction chamber, which includes an upper dome 21, a lower dome 3, and a chamber side wall 4 disposed between the upper dome 21 and the lower dome 3. The chamber side wall 4 is provided with a first inlet 51 for introducing process gas and a first outlet 52 for discharging process gas, and further includes a shielding member 22. The shielding member 22 is disposed opposite to the upper dome 21 and above the first outlet 52, and is used to block the process gas from contacting the upper dome 21.

[0024] The epitaxial reaction chamber provided in this embodiment uses a shielding member that is disposed opposite to the upper dome 21 and above the first gas outlet 52 to block the process gas from contacting the upper dome 21, so that the reaction by-products generated by the process gas during the process do not deposit on the upper dome 21, but deposit on the shielding member 22. Since the shielding member 22 is disposed inside the epitaxial reaction chamber and is less affected by the air-cooling system outside the epitaxial reaction chamber, the reaction by-products deposited on the shielding member 22 can be easily etched away, thereby avoiding the deposition of reaction by-products on the shielding member 22, reducing the probability of reaction by-products falling on the wafer, improving the process quality, and reducing the erosion of the reaction by-products on the upper dome 21 and the shielding member 22, as well as the probability of reaction by-products falling on other components inside the epitaxial reaction chamber, reducing the erosion of the reaction by-products on other components, thereby extending the maintenance cycle and service life of the epitaxial reaction chamber, and improving the production capacity.

[0025] Specifically, the lower dome 3, the chamber sidewall 4, and the upper dome 21 are hermetically connected in sequence from bottom to top in the vertical direction to form an epitaxial reaction chamber. A susceptor 1 for carrying a wafer is disposed in the epitaxial reaction chamber. The susceptor 1 is located below the upper dome 21 and the shielding member 22 and above the lower dome 3. The chamber sidewall 4 surrounds the susceptor 1. During the process, the process gas is introduced from the first gas inlet 51 between the shielding member 22 and the susceptor 1 and discharged from the first gas outlet 52 below the shielding member 22 to perform a processing operation on the wafer on the susceptor 1. Since the process gas flows between the shielding member 22 and the susceptor 1 during the process, the process gas does not contact the upper dome 21, which causes no reaction by-products generated by the process gas to deposit on the upper dome 21. The reaction by-products will only deposit on the shielding member 22. Since the shielding member 22 is located inside the epitaxial reaction chamber and is less affected by the air-cooling system outside the epitaxial reaction chamber, when using a cleaning gas (such as hydrogen chloride gas) to etch the reaction by-products on the shielding member 22, due to the relatively high temperature of the shielding member 22, the reaction by-products on the shielding member 22 can be easily etched away by the cleaning gas. In this way, the deposition of reaction by-products on the shielding member 22 can be avoided, thereby reducing the probability of reaction by-products falling on the wafer on the susceptor 1, improving the process quality, and reducing the erosion of the reaction by-products on the upper dome 21 and the shielding member 22, as well as the probability of reaction by-products falling on other components (such as the susceptor 1 and the chamber sidewall 4) inside the epitaxial reaction chamber, reducing the erosion of the reaction by-products on other components, thereby extending the maintenance cycle and service life of the epitaxial reaction chamber, and improving the production capacity.

[0026] In this embodiment, the shielding member 22 is parallel to the upper dome 21, and the orthographic projection of the shielding member 22 at least coincides with the part of the upper dome 21 in the epitaxial reaction chamber.

[0027] Specifically, the shielding member 22 is disposed below the upper dome 21 and above the base 1, and the shielding member 22 is parallel to the upper dome 21. During the process, the process gas flows between the shielding member 22 and the base 1. By making the orthographic projection of the shielding member 22 at least coincide with the part of the upper dome 21 in the epitaxial reaction chamber, the shielding member 22 can completely shield the part of the upper dome 21 in the epitaxial reaction chamber, thereby realizing that the shielding member 22 blocks the contact between the process gas and the upper dome 21.

[0028] As Figure 1 shown, in the first embodiment of the present invention, an annular groove 41 is provided in the chamber sidewall 4, the shielding member 22 is disposed in the annular groove 41, and the chamber sidewall 4, the upper dome 21 and the shielding member 22 form a barrier chamber 42. The annular groove 41 is used to support the shielding member 22, and a relatively large distance is provided between the upper dome 21 and the shielding member 22 by means of the barrier chamber 42, so as to further reduce the influence of the external air-cooling system of the epitaxial reaction chamber on the shielding member 22, so that the shielding member 22 can be maintained at a relatively high temperature state, so as to improve the etching effect of the cleaning gas on the reaction by-products deposited on the shielding member 22, thereby further avoiding the deposition of reaction by-products on the shielding member 22, further improving the process quality, extending the maintenance period and service life of the epitaxial reaction chamber, and further improving the production capacity.

[0029] In the first embodiment of the present invention, a second air inlet 61 and a second air outlet 62 are provided in the chamber sidewall 4. Among them, the second air inlet 61 is located between the upper dome 21 and the shielding member 22 and is used to introduce a barrier gas into the barrier chamber 42; the second air outlet 62 is used to discharge the barrier gas in the barrier chamber 42. Introducing a barrier gas into the barrier chamber 42 is to block the process gas from entering the barrier chamber 42 through the gap between the shielding member 22 and the annular groove 41, so as to further avoid the contact between the process gas and the upper dome 21, thereby further avoiding the deposition of reaction by-products generated by the process gas during the process on the upper dome 21, and further improving the process quality, extending the maintenance period and service life of the epitaxial reaction chamber, and improving the production capacity.

[0030] In the first embodiment of the present invention, the process gas may include hydrogen, and the barrier gas may include hydrogen. This is because in the epitaxial process, the process gas usually includes hydrogen. Therefore, by using hydrogen as the barrier gas, it is avoided that the barrier gas flows into the gap between the shielding member 22 and the base 1 through the gap between the shielding member 22 and the annular groove 41, which affects the process result of the wafer. That is to say, even if the barrier gas flows into the process gas between the shielding member 22 and the base 1, since the process gas itself contains hydrogen, the barrier gas will not affect the process effect of the process gas. However, the type of the barrier gas is not limited to this and can be adjusted according to the type of the process gas.

[0031] In the first embodiment of the present invention, the epitaxial reaction chamber further includes an intake assembly provided at the first intake port 51 to supply process gas, and an exhaust assembly provided at the first exhaust port 52 for the process gas to be discharged. The second exhaust port 62 is communicated with the first exhaust port 52 through an exhaust passage to discharge the barrier gas in the barrier chamber 42.

[0032] As Figure 2 shown, in the second embodiment of the present invention, the shielding member 22 is hermetically connected to the chamber sidewall 4 to prevent the process gas from passing through the gap between the shielding member 22 and the chamber sidewall 4 and contacting the upper dome 21, thereby further preventing the reaction by-products generated by the process gas during the process from depositing on the upper dome 21, further improving the process quality, extending the maintenance cycle and service life of the epitaxial reaction chamber, and thus improving the production capacity.

[0033] In the second embodiment of the present invention, the barrier chamber 42 is filled with an inert gas. This is because during the process, the air pressure of the process gas between the shielding member 22 and the base 1 is sometimes higher than the atmospheric pressure. If the space between the shielding member 22 and the upper dome 21 is in a vacuum, the shielding member 22 will be damaged due to excessive pressure from the process gas, and the high-temperature and high-pressure process gas surging into the space between the shielding member 22 and the upper dome 21 will also cause the upper dome 21 to be damaged. Therefore, it is necessary to fill the gas between the shielding member 22 and the upper dome 21 to make the pressure between the shielding member 22 and the upper dome 21 at a certain level to avoid the damage of the shielding member 22 and the upper dome 21 and improve the stability and safety of the operation of the epitaxial reaction chamber. Moreover, since the inert gas has stable chemical properties and is difficult to undergo chemical reactions, even if the shielding member 22 or the upper dome 21 is damaged and the inert gas leaks out of the epitaxial chamber through the upper dome 21 or leaks between the shielding member 22 and the base 1 through the shielding member 22, no danger will occur, thus improving the stability and safety of the epitaxial reaction chamber.

[0034] In the first and second embodiments of the present invention, the shielding member 22 is made of transparent quartz material and has a thickness of 2 mm - 5 mm.

[0035] In practical applications, when a heating lamp group is provided outside the epitaxial reaction chamber and the process gas inside the epitaxial reaction chamber during the process is brought to the process temperature by using the heating lamp group, the upper dome 21 and the shielding member 22 can both be made of transparent quartz material, so that the light emitted by the heating lamp group can pass through the upper dome 21 and the shielding member 22 and enter the inside of the epitaxial reaction chamber, thereby bringing the process gas inside the epitaxial reaction chamber to the process temperature by means of the heating lamp group. Moreover, during the process, a temperature measuring device, such as an infrared thermometer, can also be used to measure the temperature inside the epitaxial reaction chamber through the upper dome 21 and the shielding member 22. For the epitaxial reaction chamber provided in this embodiment, by preventing reaction by-products from depositing on the upper dome 21 and the shielding member 22, the upper dome 21 and the shielding member 22 can maintain good light transmittance, thereby improving the measurement accuracy of the temperature measuring device, and this can also improve the process quality.

[0036] The thickness of the shielding member 22 is set to 2 mm - 5 mm to prevent the shielding member 22 from deforming under the influence of the high-temperature environment during the process. Additionally, the thickness of the upper dome 21 can also be set to 2 mm - 5 mm. However, the thicknesses of the upper dome 21 and the shielding member 22 are not limited thereto.

[0037] In the first and second embodiments of the present invention, the vertical distance between the shielding member 22 and the upper dome 21 ranges from 5 mm to 10 mm.

[0038] In the first and second embodiments of the present invention, a protrusion 211 is provided at the edge of the upper dome 21. The protrusion 211 can serve as the force-receiving part of the sealing fixture to prevent the sealing fixture from acting on the upper dome 21 and the shielding member 22 and causing damage to the upper dome 21 and the shielding member 22. By applying a downward pressure to the protrusion 211 with the sealing fixture, the upper dome 21 is pressed downward, so that the upper dome 21 and the shielding member 22 are tightly pressed against the chamber sidewall 4, thereby achieving the sealing between the upper dome 21, the shielding member 22 and the chamber sidewall 4.

[0039] In summary, the reaction chamber provided by the present invention can reduce the deposition of reaction by-products, thereby improving the process quality, extending the maintenance cycle and service life of the reaction chamber, and increasing the production capacity.

[0040] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. An epitaxial reaction chamber, comprising an upper dome, a lower dome, and a chamber sidewall disposed between the upper dome and the lower dome. The upper dome, the chamber sidewall, and the lower dome are sequentially and sealingly connected to form the epitaxial reaction chamber. A first gas inlet for introducing process gas and a first gas outlet for discharging the process gas are provided on the chamber sidewall. A heating lamp group is disposed outside the upper dome, characterized in that, It further includes a shielding member disposed opposite to the upper dome. The shielding member is disposed below the upper dome and above the first air outlet. An annular groove is provided in the side wall of the chamber. The shielding member is disposed in the annular groove, and the side wall of the chamber, the upper dome, and the shielding member form a barrier chamber for blocking the process gas from contacting the upper dome. Both the upper dome and the shielding member are made of transparent quartz material. The light emitted by the heating lamp group can pass through the upper dome and the shielding member and enter the interior of the epitaxial reaction chamber, so as to make the process gas in the interior of the epitaxial reaction chamber reach the process temperature during the process by means of the heating lamp group.

2. The epitaxial reaction chamber according to claim 1, wherein The shielding member is parallel to the upper dome, and the orthographic projection of the shielding member at least coincides with the part of the projection of the upper dome in the epitaxial reaction chamber.

3. The epitaxial reaction chamber according to claim 2, wherein A second air inlet and a second air outlet are provided in the side wall of the chamber. Among them, the second air inlet is located between the upper dome and the shielding member for introducing a barrier gas into the barrier chamber. The second air outlet is used for discharging the barrier gas in the barrier chamber.

4. The epitaxial reaction chamber according to claim 3, wherein, The process gas includes hydrogen, and the barrier gas includes hydrogen.

5. The epitaxial reaction chamber according to claim 3, wherein, The epitaxial reaction chamber further includes an intake assembly provided at the first air inlet for supplying the process gas, and an exhaust assembly provided at the first air outlet for discharging the process gas. The second air outlet is communicated with the first air outlet through an exhaust passage.

6. The epitaxial reaction chamber according to claim 2, wherein The shielding member is hermetically connected to the side wall of the chamber.

7. The epitaxial reaction chamber according to claim 6, wherein, An inert gas is filled in the barrier chamber.

8. The epitaxial reaction chamber according to any one of claims 1-7, characterized in that, The shielding member is made of transparent quartz material and has a thickness of 2 mm - 5 mm.

9. The epitaxial reaction chamber according to any one of claims 1-7, characterized in that, The vertical distance between the shielding member and the upper dome ranges from 5 mm to 10 mm.

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