TWI484549B - Method for wet-cleaning parts of semiconductor apparatus - Google Patents

Description

Wet cleaning method for cleaning parts of semiconductor equipment

The present invention relates to a wet cleaning apparatus and method for cleaning parts of a semiconductor device, and more particularly to a part for cleaning a Metal-organic Chemical Vapor Deposition (MOCVD) apparatus. Wet cleaning equipment and methods.

Organometallic chemical vapor deposition (MOCVD) is a method of growing a semiconductor thin film on a substrate.

When MOCVD grows a film, mainly when a carrier gas passes through a container of an organic metal reaction source, the saturated vapor of the reaction source is brought into the reaction chamber to be mixed with other reaction gases, and then a chemical reaction occurs on the heated substrate. Promote the growth of the film. In general, the carrier gas is usually hydrogen, but in some special cases nitrogen is used (for example, when growing an indium gallium nitride (InGaN) film). Commonly used substrates are gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), bismuth (Si), tantalum carbide (SiC), and sapphire (Al ₂ O ₃ ). The commonly grown thin film materials are mainly tri-five compound semiconductors (eg, gallium arsenide (GaAs), aluminum gallium arsenide (AlGaAs), aluminum indium gallium phosphide (AlGaInP), aluminum indium gallium nitride (AlInGaN)). Or a group of six or six compound semiconductors, these semiconductor films are used in optoelectronic components (such as: light-emitting diodes (LED), laser diodes and solar cells) and microelectronic components (for example: heterojunction) Fabrication of bipolar transistor (HBT) and pseudomorphic high electron mobility transistor (PHEMT).

The components of the MOCVD system can generally include a reaction chamber, a gas control and mixing system, a reaction source, and an exhaust gas treatment system.

The Reactor Chamber is mainly where all gases are mixed and reacted. The cavity is usually made of stainless steel or quartz, and the inner wall of the cavity usually consists of quartz, graphite or high-temperature ceramics. Lined. There is a carrier in the cavity for carrying the substrate, which must be able to efficiently absorb the energy provided by the heater. The temperature required for film growth is not able to react with the reaction gas, so it is mostly made of graphite or graphite coated with lanthanum carbide (SiC).

The carrier gas flows into the system from the most upstream supply end of the system, and the flow of gas in each of the pipes into the reaction chamber is controlled by adjustment of a flow controller (MFC). Before these gases flow into the reaction chamber, they must first pass through a set of gas switching routers (Run/Vent Switch) to determine whether the gas in the pipeline should flow into the reaction chamber (Run) or directly to the exhaust gas line at the end of the reaction chamber ( Vent). The gas flowing into the reaction chamber can participate in the reaction to grow the film, and the gas directly discharged into the exhaust pipe at the end of the reaction chamber does not participate in the film growth reaction.

The reaction source can be divided into two types, the first one being an organometallic reaction source and the second being a hydride gas reaction source. The organometallic reaction source is stored in a sealed stainless steel tank with two external piping. When the metal reaction source is used, the two external piping are connected to the MOCVD machine by VCR joints. The lines of the stage are tightly coupled, and the carrier gas can flow out from one end and flow out from the other end to carry out the saturated vapor of the reaction source, thereby being able to flow to the reaction chamber. The hydride gas is stored in a gas-tight cylinder and is controlled by a pressure regulator (Regulator) and a flow controller to control the flow of gas into the reaction chamber. Commonly used organometallic reaction sources are Trimethylgallium (TMGa), Triethylgallium (TEG), Trimethylaluminum (TMAl), Triethylaluminum (TEAl), Trimethylindium (TMIn). ), Bis(cyclopentadienyl)magnesium (Cp2Mg), Diisopropyltelluride (DIPTe), and the like. Commonly used hydride gases are hydrogen arsenide (AsH ₃ ), phosphine (PH ₃ ), hydrogen nitride (NH ₃ ), unsymmetric Dimethylhydrazine (UDMHY), and cesium ethane (Si ₂ H). ₆ ) Wait.

The exhaust system is located at the very end of the system and is responsible for adsorbing and treating all toxic gases passing through the system to reduce environmental pollution.

Therefore, in the MOCVD equipment, since the carrier disk, the quartz lining, the graphite lining, the insulating support, and the metal support are exposed to the reaction source of the reaction chamber as well as the wafer, these carrier disks, quartz lining, and graphite are Lining, insulating brackets, and metal supports are also contaminated, affecting subsequent processes.

One method of conventionally removing contaminants from a carrier disk is the scraping method. however, The scraping method easily destroys these parts of the MOCVD apparatus, and does not effectively scrape the contaminants of the pits of the carrier disk, and is also highly susceptible to damage to the SiC layer.

Another method of removing contaminants is a high temperature baking process in which a carrier disk is baked using a high temperature of 1450 ° C plus nitrogen or hydrogen to remove contaminants at high temperatures. However, such a high-temperature baking method is liable to cause damage or decomposition of the SiC layer, and in addition, a large amount of electric power is wasted, which is rather disadvantageous from the viewpoint of energy saving.

Accordingly, it is an object of the present invention to provide a semiconductor device for cleaning The wet cleaning equipment and method of the parts can clean the parts at a low cost at a low cost, so that these parts can be reused in the MOCVD process in particular.

To achieve the above object, the present invention provides a wet cleaning apparatus for cleaning a component of a semiconductor device, comprising a fixed structure, a chemical reaction device, a cleaning device, and a drying device. The chemical reaction device is disposed on the fixed structure for accommodating an alkaline chemical and heating the alkaline chemical to a first temperature. A dirty part is immersed in an alkaline chemical. The dirty part contains a clean part and a waste layer deposited on it. The alkaline chemical having the first temperature reacts with the waste layer to remove the waste layer. Parts, and get clean parts with alkaline chemicals. The cleaning device is disposed on the fixed structure and provides a cleaning liquid to clean the alkaline chemicals on the clean parts to obtain clean parts with the cleaning liquid. The drying device is disposed on the fixed structure for drying the clean parts with the cleaning liquid at a second temperature to obtain clean parts without alkaline chemicals and cleaning liquid.

The present invention also provides a wet cleaning method for cleaning a part of a semiconductor device, comprising: a thermochemical reaction step of immersing a dirty part in an alkaline chemical in a chemical reaction device, and adding a base The chemical agent is heated to a first temperature, the dirty part comprises a clean part and a waste layer deposited thereon, and the alkaline chemical having the first temperature reacts with the waste layer to move the waste layer away from the clean part, and Obtaining clean parts with an alkaline chemical; a cleaning step: providing a cleaning solution to clean the alkaline chemicals on the clean parts to obtain clean parts with the cleaning liquid; and a drying step: in a second Dry the clean parts with the cleaning solution at a temperature to obtain clean parts without alkaline chemicals and cleaning solutions.

By the wet cleaning device and method of the present invention, in addition to being able to be at a low temperature In addition to removing the wafer carrier disk for MOCVD, it is also possible to clean the MOCVD coating on the parts used in MOCVD such as quartz lining, graphite lining, insulating support, and metal support. Since the chemical reaction is used to remove the MOCVD coating, it is possible to remove the MOCVD coating without using a high temperature environment of up to 1450 ° C, and it is not necessary to use a scraping method to damage the parts. Furthermore, it is also difficult to generate acid corrosion for MOCVD parts by using an alkaline chemical. Therefore, the present invention can achieve an effect superior to the prior art in terms of energy saving and component protection.

In order to make the above description of the present invention more comprehensible, a preferred embodiment will be described below in detail with reference to the accompanying drawings.

S41‧‧‧ Thermochemical reaction steps

S42‧‧‧ cleaning steps

S43‧‧‧ drying step

10‧‧‧Fixed structure

20‧‧‧Chemical reaction device

21‧‧‧Alkaline chemicals

22‧‧‧ liquid tank

23‧‧‧ Cover

24‧‧‧heater

25‧‧‧Exhaust fan

26‧‧‧ thermostat

27‧‧‧Power switch

28‧‧‧heating switch

29‧‧‧Emergency stop switch

30‧‧‧cleaning device

31‧‧‧ cleaning solution

40‧‧‧Drying device

41‧‧‧Gas supply module

42‧‧‧ oven

50‧‧‧Transportation agencies

90‧‧‧Dirty parts

91‧‧‧Clean parts

92‧‧‧Waste layer

100‧‧‧ Wet cleaning equipment

421‧‧‧ entrance

422‧‧‧fan

423‧‧‧heater

424‧‧‧ Storage rack

425‧‧ Export

1 shows a schematic diagram of a wet cleaning apparatus for cleaning parts of a semiconductor device in accordance with a preferred embodiment of the present invention.

Figure 2 shows a schematic of the chemical reaction unit of Figure 1.

Figure 3 shows a schematic view of the drying apparatus of Figure 1.

4 shows a flow chart of a wet cleaning method for cleaning a part of a semiconductor device in accordance with a preferred embodiment of the present invention.

5A and 5B are photographs showing the parts for cleaning a semiconductor device before and after cleaning, respectively, using a preferred embodiment of the present invention.

In MOCVD equipment, in addition to the carrier-bearing disk (or wafer carrier) carrying the wafer, the quartz lining, graphite lining, insulating support, and metal support in the MOCVD equipment are exposed to the wafer as well. In the reaction source of the reaction chamber, these carrier plates, quartz linings, graphite linings, insulating supports, and metal supports are also contaminated, affecting subsequent processes. Therefore, the wet cleaning apparatus and method for cleaning parts of a semiconductor device of the present invention can be used in MOCVD, such as quartz lining, graphite lining, insulating support, and metal support, in addition to being able to remove the carrier. The MOCVD coating on the part.

1 shows a clean semiconductor for use in accordance with a preferred embodiment of the present invention Schematic of the wet cleaning apparatus 100 of the parts of the device. As shown in FIG. 1, the wet cleaning apparatus 100 of the present embodiment includes a fixed structure 10, a chemical reaction device 20, a cleaning device 30, and a drying device 40.

The fixing structure 10 can be a floor, a floor or a large frame, etc., and the chemical reaction device 20, the cleaning device 30 and the drying device 40 can be fixedly or movably or rotatably disposed thereon, or any chemical reaction device can be used. 20. The cleaning device 30 and the drying device 40 are coupled together to prevent a connection structure that is dumped or displaced from each other.

The chemical reaction device 20 is disposed on the fixed structure 10 for accommodating an alkaline chemical 21 and heating the alkaline chemical 21 to a first temperature. In the present embodiment, the first temperature ranges from room temperature (25 ° C or 300 K) to 300 ° C, preferably 80 to 150 ° C, which is much lower than the 1450 ° C of the prior art. A dirty part 90 is immersed in the alkaline chemical 21 of the chemical reaction unit 20. The soiled part 90 includes a clean part 91 and a waste layer (MOCVD coating) 92 deposited thereon. The alkaline chemical 21 having the first temperature reacts with the waste layer 92 to move the waste layer 92 away from the clean part 91 to obtain a clean part 91 contaminated with the alkaline chemical 21.

In one example, the composition of the alkaline chemical 21 comprises a hydroxyl group (OH-group) and hydrogen peroxide (H ₂ O ₂ ), and the composition of the waste layer 92 comprises a layer selected from aluminum (Al), gallium (Ga). And a group consisting of indium (In). That is, a combination of any ratio of a hydroxyl group (OH-group) to hydrogen peroxide (H ₂ O ₂ ) can be considered as the alkaline chemical agent 21 of the present embodiment. The source of the hydroxyl group (OH-group) may be derived from potassium hydroxide (KOH), sodium hydroxide (NaOH) or the like. The reaction formula is as follows: 2 A +2 BOH +6 H ₂ O ₂ → 2 B ⁺ +2[ A ( OH ) ₄ ] ^- +3 H ₂ wherein A may be the above-mentioned Al, Ga, In, B may be the above K, Na, etc.

Taking the coating of aluminum gallium nitride as an example, the reaction formula is: 2 Al +2 NaOH +6 H ₂ O ₂ → 2 Na ⁺ +2[ Al ( OH ) ₄ ] ^- +3 H ₂

Wherein the weight ratio of the hydroxyl group (OH- group) to the hydrogen peroxide (H ₂ O ₂ ) is in the range of about 0.01 to 20, and the reaction time is about 5 to 30 minutes. It is to be noted that H ₂ O ₂ is used as a catalyst to accelerate the reaction, so that the effect of the present invention can be accomplished without H ₂ O ₂ .

In one example, the clean part 91 contaminated with the alkaline chemical 21 can be manually transported to the cleaning device 30. The cleaning device 30 is disposed on the fixed structure 10 and provides a cleaning liquid 31 to wash away the alkaline chemical 21 on the cleaned part 91 to obtain a clean part 91 contaminated with the cleaning liquid 31. The method of cleaning includes spraying, soaking, and the like. In this embodiment, The use of normal temperature deionized water (DI water) to perform the cleaning function can save the cost of heating the deionized water. In this case, since the reaction of the alkaline chemical 21 is also very complete, it is not necessary to use a brush to remove the waste layer 92 which has not been removed. However, in other embodiments, the heated deionized water may also be used as needed to perform the cleaning function.

In one example, the clean parts 91 contaminated with the cleaning liquid 31 can be manually transported to the drying unit 40. The drying device 40 is disposed on the fixed structure 10 for drying the clean parts 91 contaminated with the cleaning liquid 31 at a second temperature to obtain the clean parts 91 without the alkaline chemicals 21 and the cleaning liquid 31. In the present embodiment, the first temperature ranges from room temperature to 300 ° C, preferably from 80 to 150 ° C, such as 100 ° C, which is much lower than the above-mentioned 1450 ° C, so that a considerable amount of heating energy can be saved. The effect of performing drying is to eliminate water stains on the parts so as not to affect the subsequent MOCVD.

It should be noted that the wet cleaning apparatus 100 may further include a transport mechanism 50, such as a mechanical arm that can perform up, down, left and right, forward and backward, and clamping parts, which are fixed on the fixed structure 10 and will be contaminated with alkali. The clean component 91 of the chemical agent 21 is transported from the chemical reaction device 20 to the cleaning device 30, and the clean component 91 contaminated with the cleaning liquid 31 is transported from the cleaning device 30 to the drying device 40. The purpose of this move is to meet the requirements of automation and save the cost of manual handling.

FIG. 2 shows a schematic diagram of the chemical reaction device 20 of FIG. As shown in FIG. 2, the chemical reaction device 20 includes a liquid tank (such as a stainless steel liquid tank) 22, a cover (such as a stainless steel cover) 23, a heater (such as a ceramic fiber heater) 24, and a plurality of The heat exhaust fan 25, a temperature controller 26, a power switch 27, a heating switch 28, and an emergency stop switch 29. The liquid tank 22 contains an alkaline chemical agent 21 and a dirty part 90 therein. When the user presses the power switch 27 and/or the heating switch 28, the heater 24 is started to be heated, and the cover 23 can cover the liquid tank 22 to reduce the volatilization of the alkaline chemical 21. The thermostat 26 can control the temperature of the alkaline chemical 21 to a preset temperature using a thermometer, a heater 24, and a heat exhaust fan 25. The emergency stop switch 29 can be pressed by a user to perform a power-off function in an emergency.

Figure 3 shows a schematic view of the drying apparatus of Figure 1. As shown in Figure 3, the drying apparatus 40 can have three embodiments (A), (B), (C). Therefore, the drying device 40 may include: (A) a gas supply module 41; (B) an oven 42; or (C) a gas supply module 41 and an oven 42.

In case (A), the gas supply module 41 provides a second temperature The gas is blown and dried by the clean part 91 contaminated with the cleaning liquid 31. The second temperature ranges from 50 to 400 °C. In case (B), the oven 42 dries the clean part 91 at the second temperature. In the case (C), the gas supply module 41 supplies a gas to blow the clean parts 91 contaminated with the cleaning liquid 31. Whether the blow is dry or not, the oven 42 dries the clean parts 91 contaminated with the cleaning liquid 31 at the second temperature. The blowing and drying actions can be performed simultaneously.

In this example, the gas supply module 41 provides nitrogen. Nitrogen enters from the inlet 421 of the oven 42, passes through the fan 422 and the heater 423, and finally circulates throughout the vented storage rack 424. The clean parts 91 contaminated with the cleaning liquid 31 can be placed in the storage rack 424 for drying or Drying procedure. Excess gas can be removed from the outlet 425 of the oven 42. It should be noted that when the gas supply module 41 directly supplies the gas of the second temperature, the heater 423 and the fan 422 are components that can be omitted; or the gas supply module 41, the heater 423, and the fan 422 can also be Integrated into a module. The invention is not particularly limited thereto. In one example, the present invention uses a precision high temperature hot air circulating oven (the path of the entire cycle is shown by the direction of the arrow in FIG. 3), has an independent thermal equilibrium temperature equalizing mechanism, and is also provided with a plurality of temperature sensors therein. The heating capacity of the heater 423 is 50 to 400 ° C, preferably 100 ° C, and the temperature control accuracy is ± 0.1 ° C.

4 shows a flow chart of a wet cleaning method for cleaning a part of a semiconductor device in accordance with a preferred embodiment of the present invention. As shown in Figures 4 and 1, the wet cleaning method comprises the following steps.

First, in a thermochemical reaction step S41, the dirty part 90 is immersed in the alkaline chemical 21 in the chemical reaction device 20, and the alkaline chemical 21 is heated to the first temperature, and the dirty part 90 is clean. The part 91 and the waste layer 92 deposited thereon, the alkaline chemical 21 having the first temperature reacts with the waste layer 92 to move the waste layer 92 away from the clean part 91 to obtain a clean part impregnated with the alkaline chemical 21 91.

Then, in a cleaning step S42, a cleaning liquid 31 is supplied to wash away the alkaline chemical 21 on the cleaned part 91, thereby obtaining a clean part 91 contaminated with the cleaning liquid 31.

Next, in a drying step S43, the cleaned part 91 contaminated with the cleaning liquid 31 is dried at the second temperature to obtain a clean part 91 free of the alkaline chemical 21 and the cleaning liquid 31. The steps for drying and/or drying have been described above and will not be described in detail herein.

5A and 5B respectively show the use of the preferred embodiment of the present invention for cleaning Photographs of the parts of the semiconductor device before and after cleaning. As shown in FIG. 5A, the clean parts 91 of the entire dirty part (wafer carrying tray) are not covered by the waste layer 92 because they are covered by the wafer, and there is waste in the portion other than the clean part 91. Layer 92. As shown in Figure 5B, after cleaning with the apparatus of the present invention, the waste layer 92 is completely removed leaving an integral clean part 91. It can be seen that the apparatus and method of the present invention can achieve a relatively good cleaning effect.

According to the wet cleaning apparatus and method of the present invention, in addition to being able to remove the wafer carrier disk for MOCVD at a low temperature, it can also be used for cleaning MOCVD in quartz lining, graphite lining, insulating support, and metal support. The MOCVD coating on the part. Since the chemical reaction is used to remove the MOCVD coating, it is possible to remove the MOCVD coating without using a high temperature environment of up to 1450 ° C, and it is not necessary to use a scraping method to damage the parts. Furthermore, it is also difficult to generate acid corrosion for MOCVD parts by using an alkaline chemical. Therefore, the present invention can achieve an effect superior to the prior art in terms of energy saving and component protection. It is worth noting that multiple parts can be processed together with the chemical reaction device, the cleaning device and the drying device, thereby saving man-hours and costs.

The specific embodiments of the present invention are intended to be illustrative only and not to limit the invention to the above embodiments, without departing from the spirit of the invention and the following claims. The scope of the invention and the various changes made are within the scope of the invention.

S41‧‧‧ Thermochemical reaction steps

S42‧‧‧ cleaning steps

S43‧‧‧ drying step

Claims (5)

A wet cleaning method for cleaning a part of a semiconductor device, comprising: (a) a thermochemical reaction step of immersing a dirty part in an alkaline chemical in a chemical reaction device and basifying the alkaline The chemical agent is heated to a first temperature, the dirty part comprising a clean part and a waste layer deposited thereon, the alkaline chemical having the first temperature reacting with the waste layer to remove the waste layer The clean part obtains the clean part with the alkaline chemical; (b) a cleaning step: providing a cleaning liquid to wash off the alkaline chemical on the clean part, and obtaining the cleaning liquid And the (c) drying step of: drying the cleaned part contaminated with the cleaning liquid at a second temperature to obtain the clean part without the alkaline chemical and the cleaning liquid. The method of claim 1, wherein the component of the alkaline chemical comprises a hydroxyl group (OH-group), and the component of the waste layer comprises a material selected from the group consisting of aluminum (Al), gallium (Ga), and A group of indium (In). The method of claim 1, wherein the drying step comprises: providing a gas having the second temperature to dry the cleaned part impregnated with the cleaning liquid; or dip at the second temperature The clean part of the cleaning liquid is dried. The method of claim 1, wherein the drying step comprises: providing a gas to blow the clean part impregnated with the cleaning liquid; and applying the cleaning liquid to the second temperature Clean parts to dry. The method of claim 1, wherein the first temperature ranges from room temperature to 300 ° C and the second temperature ranges from 50 to 400 ° C.