TW594876B - Method and apparatus for removing condensed processing gas in a load lock chamber - Google Patents

Abstract

A method and an apparatus for removing a condensed processing gas in a load lock chamber are provided. A hot gas and a pump device are provided for a load lock chamber of a cluster tool used for plasma etching. The processing gas condensed on a wafer is evaporated by the hot gas, and the hot gas as well as the evaporated processing gas are pumped out from the load lock chamber by using the pump device.

Description

594876 V. Description of the invention (1) Plasma etching method and device, especially the technical field to which the invention belongs The present invention relates to a method

About a method and device for removing condensing process gases from the negative pressure h " " " " " " " " " " " " " " " " " " " " The process involves engraving the gas etching gas with a surname ί f f: 'Reuse radio frequency (RF0 frequency) to generate electrical equipment. Denso contains radicals and positive and negative radicals. From 墼 to Γ, radicals will diffuse and adsorb to the wafer surface, while ions will bombard as early as 4 = round surface 'to physically remove the material on the wafer surface. In the process of ionization, the chemical bonds between the atoms on the wafer surface will be destroyed, so: With the help of the bombardment, the above radicals can quickly react with the atoms or molecules on the ^ μ plane and form Gaseous by-products from the gas-centered field are easily volatile, can be desorbed from the wafer surface, and are discharged from the reaction chamber via convection gas in the submicron 1C wafer. 'Shallow trench insulation (shal low Trench electrical isolation (STI) requires the use of plasma to etch single crystal silicon to complete the slurry. When monocrystalline silicon is etched, silicon dioxide or silicon dioxide / nitride nitride hard masks are generally used instead. Photoblocking to avoid contamination. The monocrystalline silicon money engraving system uses a blocking mechanism (b 1 ock i ng mechani sm) so that the direction of the engraving is mainly vertical. The main money engraving agent is Η B r, and% is the medium for passivation of the sidewall. Protect the integrity of the sidewall. ΗΒγ will decompose in the plasma and release > stink element free radicals, which will react with Shi Xi to form volatile silicon tetrabromide (S i Bi: 4). Oxygen oxidizes silicon in the sidewalls to form dioxygen

Page 5 V. Description of the invention (2) --- + ^ ^ Siloxane does not react with bromoxin free radicals. At the bottom of the trench, the oxide will not grow, so the etching process can only be performed in the vertical direction. a, s. In the process integration process of advanced wafer fabs, such processes are commonly used in cluster tools with clusters (Cluster execution = integration of different processes in a system, so that The rest days are reduced to increase production capacity. And because the wafer transfer between reaction chambers of different processes is performed in a vacuum environment, it can reduce the chance of wafers being polluted by the external atmospheric environment, so it can achieve a relatively High yield. Figure 丨 shows the layout of the cluster tool 1000 for the dry etching process, which specifically refers to the process of plasma etching single crystal silicon using HBr as the process gas. This cluster tool 100 includes transportation Transfer chamber 102, robotic arm 104, load chambers 12 and 114, plasma reaction process chamber 106 and other process reaction chambers (not specifically marked in the figure) / reaction chambers and The reaction chambers are connected by a slit valve (s 1 itva 1 ve) and other vacuum valves that can be used to control the switch between the two reaction chambers and maintain good isolation from the outside world, such as Figure 1 in The vacuum valve 112a is sent between the reaction chamber 丨 〇2 and the load-112. To the wafer that has undergone the single-crystal silicon plasma etching process, HBr residues are often condensed on the wafer surface, and HBr comes into contact with water and gas ^ Dong metal is corrosive. The cluster tool 100 can be separated by the vacuum valve U 2a outside the "environment", however, the load chamber 112 must be in contact with the outside a. The atmospheric environment. Therefore, the inside of the load chamber 112 contains the authentic two pieces 112a, the indexer, the wall of the load chamber, and the leak port.

594876

Port): Pumping port, purge port and other ports used for recirculation, as well as standards for feeding and removing wafers into and out of the load chamber 1 1 2

The mechanical arm (standard mechanical interface airin (SMIF arm)) can easily be condensed on the wafer by the muscle factory smut of 0 HBr because of its contact with the atmosphere. It will cause the following problems on the wafer surface: · 1 · Product problems: The product problem here is divided into two parts, one is the contamination of the product caused by the above-mentioned rotten silver, and the other is the impact of condensed ΗΒγ on the wafer on the subsequent process. The above-mentioned corrosion will cause the wafer inspection results to perform poorly and cause a first wafer event. Dozens of wafers are usually stored in the index box first and then entered into the load chamber 112 to save processing time. Since the first wafer that enters the index box stays in the load chamber 112 for the longest time, so The level of contamination is most severe. The contamination includes the contamination of the product caused by the above-mentioned hardware equipment and the contamination of the wafer by HBr condensed on the wafer. 2 · Manpower inquiry · The solution to this problem is that we must have a preventive maintenance (PM) wet cleaning process and remove it manually by using isopropanol (IPA). Corrosives on the part surface and in the load chamber 112. This method of manual cleaning by manpower requires not only a lot of manpower support, but also frequent implementation ', which will increase the maintenance cost of Yiyi. And because of the clean environment, there is a local concentration of HBr ', which can easily cause safety problems. 3. Cost issue: In addition to the labor cost of instrument maintenance mentioned above, when you find that the pollution is too serious, you need to sacrifice a wafer to test the process environment.

Page 7 Invention Description (4), these frequent inspections will increase the manual manual cleaning and material inspection of raw materials. And when you enter the machine, please come and collect your own private land. This process machine must be stopped. Ai indirectly increases the production of the invention. SUMMARY OF THE INVENTION The object of the present invention is to provide a process gas and method for reducing pollution. In accordance with the above object of the present invention, a method and an apparatus for a process gas are proposed. The hot process gas is evaporated, and the process gas concentration is reduced by the evacuation setting to avoid process contamination. According to a preferred embodiment of the present invention, the upper gas is hydrogen bromide. According to the present invention, the setting range is between 70 ° C and 100 ° C, and between ° C, and a more preferable temperature value is 80. The range is 150 seem to 250 seem. It can be known from the above-mentioned preferred embodiments of the present invention. Since the present invention can effectively reduce and extend the service life of the load chamber and its internal parts to pre-manipulate the robot arm, it can increase the P early and the yield of the process. In addition, a process gas removed from the load chamber is used to remove the process gas from the load chamber and the wafer. A purge gas removed from the load chamber is condensed on the wafer for pumping, so that the residual gas on the wafer is The purge gas caused by the equipment is nitrogen gas. A preferred embodiment of the process is that the temperature of nitrogen gas is preferably in the range of 75 t to 85 ° C. In addition, the preferred flow rate of nitrogen. ’The application of the present invention has the following HBr concentrations in the low load chamber, so the safety of the equipment maintenance staff of the standard maintenance machine that transports wafers into the load chamber’ is reduced.

594876 V. Description of the invention (5) The temperature and sound of the reaction chamber and the load chamber are accelerated and cooled on the surface of the wafer. Degree gradient to avoid HBr due to temperature. Due to the inventors of the present invention; ^ The heated purge gas is passed into the load chamber, and the load chamber must wait for the wafer in the normal flocculation ^ ^ β Where the method of the present invention is implemented, it is not Φ i # Therefore a / / pow. The door requires extra processing time or process space, because the circle yield rate is at the same time, it will not be able to. And the invention The installation of the pigeons ^ ^ J ^ and the soil are available from the > method. "Using traditional devices and process channels and gas" early does not need to make too much change on the process machine, ρ Can effectively solve the problems caused by the conventional HBr. The embodiment !, the invention provides a method for smashing a single crystal by plasma, using a flowing hot mash to evaporate HBr condensed on the wafer, to prevent HBr from contacting with water and gas. HB r / 〇2 plasma ㈣ single crystal unavoidable problems. "The present invention is to solve the problem of acid generation when HBr comes into contact with water vapor. In the embodiment of the present invention, the body-path is added to the load chamber 112 ::: reai-time hot bake (hot back) on the muscle of the load chamber 112. HBr can evaporate and leave the wafer surface, and it can be pulled by two. Second, > Draw out the load chamber 112 'to thoroughly contact the wafer with the inside of the load chamber 112, to avoid fine damage to the product and equipment. Refer to Figure 2', which will show the diagram of the present invention. This embodiment is the cluster in Figure 1.

An improved device of a preferred embodiment of the hardware configuration audio tool 100 is set here.

Page 9 594876 V. Description of the invention (6) ~-Taking the load chamber 11 2 as an example, the present invention can also be applied to the load chamber i i 4 and other reaction chambers with the same purpose. The load chamber 112 has a purge port 206 for introducing an inert gas into the load chamber 112 to remove other gases or particles in the chamber. In the present invention, a gas temperature control device 202 is installed between the nitrogen pipeline connected to the purge port 206 and the service end to heat the introduced nitrogen gas. The present invention also uses an exhaust pump 204 connected to the exhaust port 208 to extract hot nitrogen through the "exhaust port 20 8" and leave the load chamber 2. In this way, the condensed HBr on the wafer is evaporated using a passive gas, and the HBr is taken out of the load chamber 112. The above-mentioned inert gas may be, for example, nitrogen or compressed dry air, and nitrogen is preferably selected. The reason for selecting nitrogen is that nitrogen is a stable gas, and it is not easy to affect the process. In addition, nitrogen is an easily available and low-cost gas in semiconductor wafers and does not cause much additional cost burden. In the compressed dry air, there will still be a little water vapor residue, which may react with the Η B r on the wafer / spinning to generate a small amount of acid, which is less in line with the requirements of the present invention. It needs to be controlled by gas temperature control device 200 in the temperature range of 70 ° C to 100 ° C. The preferred temperature range is between 7 5 ° C and 8 5 ° C. The reason is about 80 ° C. From the measurement results, it is known that the I inn · degree of the wafer in the reaction chamber of the plasma etching process is about 80 ° C. Therefore, the wafer can withstand at least about 8 °. In addition, if the temperature gradient of the wafer between the plasma etching process reaction chamber 丨 〇6 and the load chamber Π2 is close to zero, HBr can be prevented from accelerating to cool and condense on the wafer surface due to temperature reduction. For the above two reasons, this embodiment sets the control temperature of the gas temperature control device 202 to 80 ° C.

Page 10 594876 V. Description of the invention (7) According to a preferred embodiment of the present invention, it further includes a gas flow control device 21 to adjust the flow rate of the gas sent into the load chamber. The gas flow control device 210 is connected between the gas temperature control device 202 and the purge port 206, or-between the gas temperature control device 202 and the plant service side. In a preferred embodiment, the gas flow rate sent to the load chamber via the gas flow control device 2 10 is generally determined by the specifications of the load chamber 112, the clear port 206 and the suction port 208 in the load chamber 1_1. The placement position in 2 'and the number of wafers loaded in the load chamber 2 are determined. In this embodiment, its preferred flow rate is between 15 0 s c c m and 2 0 0 s c c m. A wafer that has been plasma-etched using an old, unimproved device when taken out of the load chamber 丨 2 'The HBr concentration on the wafer is much larger than the range that the instrument can measure (> 9 ppm)' and is still exposed to the atmosphere It takes 丨 seconds for the residual concentration to drop to 1 ppm. However, when a wafer 'plasma etched using the improved device of the present invention is taken out from the load chamber 112, the residual HBr concentration on the wafer is only 3 ppm' and after 30 seconds of exposure to the atmosphere, the residual HBr concentration drops to 0.5 ppm. This proves that the present invention can indeed remove the condensed HBr on the wafer, prevent HBr from causing corrosion of products and equipment, and reduce the pollution of the surrounding environment caused by the diffusion of HBr into the atmosphere after the wafer is removed from the load chamber 112. As can be seen from the above-mentioned preferred embodiments of the present invention, the application of the present invention has the following advantages. Since the present invention can effectively reduce the HBr concentration in the load chamber, it can prolong the wet cleaning cycle of the load chamber and reduce the time required for each wet cleaning. This can extend the load chamber and its internal parts and transport the wafer into the load. The service life of the standard robot arm of the room. The invention can not only reduce the equipment and personnel costs required for equipment maintenance, but also

Page 11 594876 Description of the Five 'Invention (8) The pollution caused by the surrounding environment is also reduced, which can improve the safety of equipment personnel who maintain the machine. As can be seen from the above-mentioned preferred embodiments of the present invention, the application of the present invention also has the following advantages. As the HBr concentration in the load chamber is reduced, the pollution caused by corrosion of equipment or wafers in the load chamber is also reduced, which can improve the yield of the process. The temperature gradient between the wafer reaction chamber and the load chamber in the plasma etching process is not too large, which can prevent HBr from accelerating cooling on the wafer surface due to the temperature decrease. And because the first wafer is heated by this hot air for the longest time, not only the conventional first wafer event can be avoided. According to the result of this embodiment, the first wafer is actually condensed on the wafer HBr is the least and its quality is the best. It can be known from the foregoing preferred embodiments of the present invention that the application of the present invention has the following advantages. Since the present invention is arranged in a load chamber, the load chamber is a place where the wafer must stay and wait during the hanging process. The method of the present invention does not need to spend extra process time or process space, so At the same time, it will not delay the efficiency of wafer production. In addition, the method is simple, and the channels and gases are installed in the traditional device and process method, and the problem caused by the book is effectively solved without the need to do too much rolling on the process machine. If the change is too big, the present invention has been disclosed as above with a preferred embodiment. 铗 = It is clear that anyone who is familiar with this skill will not leave: Invention = Limit within the limits, when various changes and retouching can be made. Therefore, the spirit and scope of = are subject to the definition of the scope of patent application attached. The protection range of 594876 is briefly explained in order to make the above and other objects, features, and advantages of the present invention more comprehensible. The following describes a preferred embodiment in conjunction with the accompanying drawings for detailed description as follows: FIG. 1 is a configuration diagram of a conventional cluster tool for plasma etching. . FIG. 2 is a device configuration diagram according to a preferred embodiment of the present invention. Symbol description 100 cluster tool 102 conveying reaction chamber 104 robot arm 106 plasma etching process reaction chamber 112 ′ 114:: load chamber 112 a: vacuum valve 202 gas temperature control device 204 pumping pump 206 cleaning port 208 pumping Port 210: gas flow control device

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Claims (1)

594876 VI. Application Patent Scope 1. A method for removing condensing process gas in a load chamber, and evaporating and sending a process gas condensed on a wafer to leave the wafer surface, the method includes at least the following steps: control The temperature of a purge gas is within a temperature range; the purge gas is passed into a load chamber; and the purge gas is extracted from the load chamber by a suction device to prevent the process gas from condensing on the wafer and This load chamber causes contamination. 2. The method for removing a condensing process gas in a load chamber as described in item 1 of the scope of the patent application, wherein the purge gas is nitrogen. 3. The method for removing a condensing process gas in a load chamber as described in item 1 of the scope of the patent application, wherein when the process gas is hydrogen bromide, the temperature range is 70 ° C to 100 ° C. 4. The method for removing a condensed process gas in a load chamber as described in item 1 of the scope of the patent application, wherein when the process gas is hydrogen bromide, the temperature range is 75 ° C to 85 ° C. 5. The method for removing the condensing process # gas in the load chamber as described in item 1 of the scope of the patent application, wherein when the process gas is hydrogen bromide, the temperature range is 800 ° C. 6. Remove the condensation process in the load chamber as described in item 1 of the scope of patent application Page 14 594876 VI. Method for applying patent gas The method of passing the purge gas into the load chamber includes a step of controlling the flow rate of the purge gas. 7. The method for removing the condensing process gas in the load chamber as described in item 1 of the scope of the patent application, wherein the flow rate of the purge gas is between 150 seem and 200 seem ° 8—a kind of removing the condensing process gas in the load chamber A method for evaporating a process gas condensed on a wafer to leave the surface of the wafer. The method includes at least the following steps: controlling the temperature of a nitrogen gas between 7 5 ° C and 8 5 ° C; Injecting the nitrogen gas into a load chamber, and making the flow rate of the nitrogen gas between 150 seem and 200 seem; and using a suction device to extract the nitrogen gas from the load chamber to prevent the process gas from condensing in the load chamber Contamination on the wafer and in the load chamber. 9. A device for removing condensed process gas in a load chamber to evaporate a process gas condensed on a wafer to leave the wafer surface, the device at least includes: a load chamber, including a clear port and a pump A gas port, so that a purge gas flows into the load chamber through the purge port, and then flows out through the pumping port; a gas temperature control device, the gas temperature control device is connected to the purge port to control the temperature of the purge gas to After it is within a temperature range, it is sent into the load chamber through the clear port. The gas temperature control device includes a Page 15 594876 VI. Scope of patent application The air inlet end and an air outlet end; and an air extraction device connected to the air exhaust port for extracting the purge gas from the load chamber. 10. The device for removing condensing process gases in a load chamber as described in item 9 of the scope of the patent application, further comprising a gas flow control device connected to the air inlet. 11. The device for removing the condensing process gas in the load chamber as described in item 9 of the scope of the patent application, further comprising a gas flow control device connected between the gas outlet and the gas outlet and the purge port, respectively. 12. A method for removing a knot on a wafer includes at least: a load chamber containing the purge gas and a gas temperature control connection for controlling the gas inlet and a gas flow control terminal sent from the purge gas. An air extraction device is provided at the gas outlet end, and a device for condensing the process gas in the load chamber is used to evaporate the condensed process gas from the surface of the wafer. The device includes a purge port and an exhaust port to allow a purge gas to pass through the device. The load chamber flows out of the load chamber through the suction port; a control device, the gas temperature control device and the purge port connect the temperature of the purge gas to a temperature range, and then enter the load chamber and the gas temperature The control device includes an air terminal; a control device is interposed between the air outlet and the clear port and is connected to the clear port; and the air extraction device is connected to the air exhaust port for self-loading Page 16 594876 VI. Scope of patent application The purge gas is extracted from the chamber. 13. A device for removing condensed process gas in a load chamber to evaporate a process gas condensed on a wafer to leave the wafer surface, the device at least comprises: a load chamber, including a clearing port and a pump A gas port, so that a purge gas flows into the load chamber through the purge port, and then flows out of the load chamber through the pumping port; a gas temperature control device, the gas temperature control device is connected to the purge port to control the purge gas After the temperature reaches a temperature range, and then sent into the load chamber through the clear port, the gas temperature control device includes an inlet end and an outlet end; a gas flow control device connected to the outlet end; and An air extraction device, which is connected to the air extraction port and is used to extract the purge gas from the load chamber. Page 17