CN102211096A - Supercritical water jet cleaning equipment - Google Patents

Abstract

The invention discloses supercritical water jet cleaning equipment which is used for cleaning a silicon wafer in a nondestructive way. The equipment comprises a supercritical water jet generating device, a cleaning chamber and a cleaning product recovery and treatment device. The supercritical water reaches the silicon wafer in a jet flow mode, a supercritical water constant-temperature constant-pressure microenvironment is formed on the surface of the silicon wafer, and the surface of the silicon wafer is cleaned in a nondestructive mode by utilizing the physical and chemical properties of the supercritical water. The invention can effectively clean the fine structure on the surface of the silicon chip and simultaneously avoid the use of a high-pressure cleaning cavity.

Description

A supercritical water jet cleaning equipment

technical field

The invention relates to the technical field of silicon chip cleaning in semiconductor manufacturing technology, in particular to a supercritical water jet cleaning device, which utilizes the physical and chemical properties of supercritical water to effectively clean semiconductor silicon chips.

Background technique

As semiconductor technology continues to expand to smaller technology nodes, silicon wafer cleaning technology is constantly being challenged. Cleaning accounts for more than one-third of the entire semiconductor manufacturing process. Traditional cleaning technology not only consumes a lot of pure water and chemical reagents, but also the cleaning power is increasingly unable to meet the requirements of new technologies.

The supercritical cleaning process represented by supercritical carbon dioxide and supercritical water has shown excellent application prospects in the semiconductor industry in terms of degumming, metal stripping, and particle removal. However, the application of supercritical fluid technology is often accompanied by high-pressure equipment, and the hidden dangers in safety cannot be ignored.

By creating a local supercritical environment on the surface of the silicon wafer, the excellent physical and chemical properties of the supercritical fluid can be utilized while avoiding the safety problems caused by high-pressure equipment.

Contents of the invention

(1) Technical problems to be solved

In view of this, the main purpose of the present invention is to provide a supercritical water jet cleaning equipment to overcome the difficulties of traditional cleaning and solve the hidden safety problems caused by large high-pressure chambers in conventional supercritical cleaning equipment.

(2) Technical solution

In order to achieve the above object, the present invention provides a supercritical water jet cleaning equipment, which comprises a supercritical water jet generation device 1, a cleaning chamber 2 and a cleaning product recovery treatment device 3, wherein, in the supercritical water jet generation device 1 The supercritical water reaches the silicon wafer in the cleaning chamber 2 in the form of a jet, and forms a supercritical water constant temperature and constant pressure microenvironment on the surface of the silicon wafer. Using the physical and chemical properties of supercritical water, the surface of the silicon wafer is non-destructively cleaned. The liquid discharged from the cleaning chamber is collected by the cleaning product recovery treatment device 3, and the liquid is subjected to impurity removal and purification treatment.

In the above scheme, the supercritical water jet generating device includes a constant flow constant speed pump 101, a heating pipeline 102, a heater 103, a heating controller 104, a temperature sensor probe 105 and a nozzle 106, wherein:

The constant-flow constant-speed pump 101 compresses the deionized water above the critical pressure, and keeps a constant flow rate to inject into the heating pipeline 102;

The heating pipe 102 is rotated and coiled outside the high-power heater 103, and a heat-conducting insulating material is embedded between the heating pipe and the heater;

The heater 103 heats the critical pressure deionized water coiled in its external heating pipe 102, and its power is regulated by the heating controller 104;

The heating controller 104 adjusts the heating power of the heater 103 by sampling the feedback signal of the temperature sensor probe 105;

The temperature sensor probe 105 is used to measure the temperature of the supercritical micro-environment between the nozzle 106 and the surface of the silicon wafer, and feed back the signal to the heating controller 104 .

In the above solution, the interior of the heating pipe 102 and the nozzle 106 is made of high temperature and oxidation resistant materials.

In the above solution, the high-temperature oxidation-resistant material is a modified oxidation-resistant titanium alloy.

In the above scheme, the cleaning room includes a cleaning room isolation cover 201, a cleaning room window 202, a vacuum chuck 203, a cleaning room exhaust pipe 204, a cleaning room liquid collection tank 205, a cleaning room drain pipe 206, a rotating motor 207, a Rod 208 and vacuum pump 209, wherein:

There is a window 202 on the isolation cover 201 of the cleaning room, which is convenient for observing the cleaning situation;

The vacuum chuck 203 is driven by the rotating rod 208 and can rotate under the drive of the rotating motor 207, and the vacuum pipeline of the vacuum chuck 203 is connected with the vacuum pump 209;

The cleaning chamber exhaust pipe 204 is used to discharge the gaseous products produced in the cleaning process;

The cleaning chamber sump 205 is located at the bottom of the cleaning chamber 2, and is used to collect liquid products produced during the cleaning process;

The cleaning chamber drain pipe 206 is used to discharge the liquid product enriched in the liquid sump of the cleaning chamber.

In the above solution, the cleaning product recovery treatment device 3 includes a cleaning liquid recovery tank for collecting the liquid discharged from the cleaning chamber 2, and performing impurity removal and purification treatment on the liquid.

(3) Beneficial effects

As can be seen from the above technical solutions, the present invention has the following beneficial effects

1. The supercritical water jet cleaning equipment provided by the present invention adopts the method of spraying supercritical water on the silicon wafer to implement cleaning, and utilizes the strong oxidizing property and good solubility and mass transfer characteristics of supercritical water to reduce the surface of the silicon wafer. Photoresist, metal, particles have good cleaning effect.

2. In the supercritical water jet cleaning equipment provided by the present invention, the high-pressure water flow enters the deep supercritical state instantaneously in the heating pipe, then sprays out from the nozzle, reaches the silicon wafer in the form of a jet, and forms a local supercritical environment on the surface of the silicon wafer , avoiding the use of large high-pressure chambers, and has higher safety performance.

3. In the supercritical water jet cleaning equipment provided by the present invention, the silicon wafer is rotated on the vacuum chuck, which can effectively improve the uniformity of cleaning the wafer.

4. The supercritical water jet cleaning equipment provided by the present invention makes the local supercritical environment on the surface of the silicon wafer relatively stable through temperature and flow control, and improves cleaning repeatability and inter-wafer uniformity.

Description of drawings

Fig. 1 is the structural representation of the supercritical water jet cleaning equipment provided by the present invention;

In the figure, a supercritical water jet generating device 1, a cleaning chamber 2, a cleaning product recovery processing device 3, a constant flow constant speed pump 101, a heating pipeline 102, a heater 103, a heating controller 104, a temperature sensor probe 105, a nozzle 106, Cleaning room isolation cover 201, cleaning room window 202, vacuum suction cup 203, cleaning room exhaust pipe 204, cleaning room sump 205, cleaning room drain pipe 206, rotating motor 207, rotating rod 208, vacuum pump 209, silicon wafer 210 .

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the following takes the removal of photoresist on the surface of a silicon wafer as a specific example, and refers to the accompanying drawings to further describe the present invention in detail.

As shown in Figure 1, Figure 1 is a schematic structural diagram of a supercritical water jet cleaning device provided by the present invention, which includes a supercritical water jet generation device 1, a cleaning chamber 2 and a cleaning product recovery treatment device 3, wherein the supercritical water jet The supercritical water in the generation device 1 reaches the silicon wafer in the cleaning chamber 2 in the form of a jet, and forms a supercritical water constant temperature and constant pressure microenvironment on the surface of the silicon wafer. Using the physical and chemical properties of the supercritical water, the surface of the silicon wafer is treated. Non-destructive cleaning, the liquid discharged from the cleaning chamber is collected by the cleaning product recovery treatment device 3, and the liquid is subjected to impurity removal and purification treatment.

The supercritical jet generation system 1 includes a constant-flow constant-speed pump 101 , a heating pipeline 102 , a heater 103 , a heating controller 104 , a temperature sensor probe 105 and a nozzle 106 . Among them: the constant flow and constant speed pump 101 compresses the deionized water above the critical pressure, and maintains a constant flow rate to inject into the heating pipe 102; Thermally conductive insulating material; the heater 103 heats the deionized water in the critical pressure state rotating and coiled in its external heating pipeline 102, and its power is regulated by the heating controller 104; the heating controller 104 passes the feedback signal of the sampling temperature sensor probe 105 Adjust the heating power of the heater 103; the temperature sensor probe 105 is used to measure the temperature of the supercritical micro-environment between the nozzle 106 and the surface of the silicon wafer, and feed back the signal to the heating controller 104. The interior of the heating pipe 102 and the nozzle 106 is made of high temperature oxidation resistant material (such as modified oxidation resistant titanium alloy, etc.).

Cleaning room 2 comprises cleaning room isolation cover 201, cleaning room window 202, vacuum suction cup 203, cleaning room exhaust pipe 204, cleaning room sump 205, cleaning room drain pipe 206, rotating motor 207, rotating rod 208 and vacuum pump 209 . Wherein: a window 202 is arranged on the cleaning room isolation cover 201, which is convenient to observe the cleaning situation; the vacuum suction cup 203 is driven by the rotating rod 208 and can rotate under the rotation of the rotating motor 207, and the vacuum pipeline of the vacuum suction cup 203 is connected with the vacuum pump 209; The chamber exhaust pipe 204 is used to discharge the gaseous product produced in the cleaning process; the cleaning chamber sump 205 is located at the bottom of the cleaning chamber 2 and is used to collect the liquid product produced in the cleaning process; the cleaning chamber drain pipe 206 is used to discharge the cleaning Liquid product enriched in chamber sump.

The cleaning product recovery treatment device 3 includes a cleaning liquid recovery tank for collecting the liquid discharged from the cleaning chamber 2 and performing impurity removal and purification treatment on the liquid.

After the deionized water (DIW) is pressurized by a constant-current constant-speed pump 101 , it is pumped into a heating pipe 102 , and the pipe is rotatably coiled outside a high-power heater 103 . The high-pressure water heats up rapidly in the pipeline 102 and enters a deep critical state, and reaches the surface of the rubber-coated silicon wafer 210 in the form of a jet through the nozzle 106, forming a local supercritical environment on the surface of the silicon wafer. , the heating controller 104 samples the jet temperature detected by the temperature sensor probe 105, and adjusts the heating power of the heater 103, so that the temperature of the supercritical jet is relatively stable.

The vacuum chuck 203 in the cleaning chamber is used to hold the silicon wafer 210 to be processed. The silicon wafer is tightly attached to the suction cup and rotates under the drive of the motor. The rotating silicon wafer shakes the liquid product generated by the reaction away from the silicon wafer in time, so as to facilitate the continuous degumming and effectively improve the uniformity of cleaning.

The photoresist on the surface of the silicon wafer 210 is rapidly oxidized in a supercritical water environment to generate simple gaseous compounds such as CO2, NO2, and H2O. The gaseous products generated in the cleaning chamber 2 are discharged through the cleaning chamber exhaust pipe 204 , while the liquid products are enriched in the liquid collection tank 205 at the bottom of the cleaning chamber and discharged through the liquid discharge pipe 206 . The liquid products generated in the cleaning chamber are discharged from the equipment after being harmlessly treated by the recycling system 3.

The supercritical water in this equipment is very corrosive to ordinary materials, so the heating pipe 102 and nozzle 106 are made of modified corrosion-resistant titanium alloy or corrosion-resistant nickel-based alloy to improve the service life of the pipe and nozzle.

The specific implementation examples described above have further described in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are only specific implementation examples of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (6)

1. A supercritical water jet cleaning device, characterized in that the equipment comprises a supercritical water jet generating device (1), a cleaning chamber (2) and a cleaning product recovery treatment device (3), wherein the supercritical water jet generates The supercritical water in the device (1) reaches the silicon chip in the cleaning chamber (2) in the form of a jet, and forms a supercritical water constant temperature and constant pressure microenvironment on the surface of the silicon chip. Using the physical and chemical properties of supercritical water, the silicon Non-destructive cleaning is performed on the sheet surface, and the liquid discharged from the cleaning chamber is collected by the cleaning product recovery treatment device (3), and the liquid is subjected to impurity removal and purification treatment. 2. supercritical water jet cleaning equipment according to claim 1, is characterized in that, described supercritical water jet generation device comprises constant flow constant speed pump (101), heating pipeline (102), heater (103), Heating controller (104), temperature sensor probe (105) and nozzle (106), wherein: The constant flow and constant speed pump (101) compresses the deionized water above the critical pressure, and maintains a constant flow rate to inject the heating pipe (102); The heating pipe (102) is rotated and coiled outside the high-power heater (103), and a heat-conducting insulating material is embedded between the heating pipe and the heater; The heater (103) heats the deionized water in the critical pressure state rotating and coiled in its external heating pipe (102), and its power is regulated by the heating controller (104); The heating controller (104) regulates the heating power of the heater (103) by sampling the feedback signal of the temperature sensor probe (105); The temperature sensor probe (105) is used to measure the temperature of the supercritical microenvironment between the nozzle (106) and the surface of the silicon wafer, and feeds back the signal to the heating controller (104). 3. The supercritical water jet cleaning device according to claim 2, characterized in that, the interior of the heating pipe (102) and the nozzle (106) is made of high-temperature oxidation-resistant materials. 4. The supercritical water jet cleaning device according to claim 3, characterized in that, the high-temperature oxidation-resistant material is a modified oxidation-resistant titanium alloy. 5. supercritical water jet cleaning equipment according to claim 1, is characterized in that, described cleaning chamber comprises cleaning chamber isolation cover (201), cleaning chamber window (202), vacuum suction cup (203), cleaning chamber exhaust Pipe (204), cleaning chamber sump (205), cleaning chamber drain pipe (206), rotating motor (207), rotating rod (208) and vacuum pump (209), wherein: There is a window (202) on the cleaning room isolation cover (201), which is convenient for observing the cleaning situation; The vacuum suction cup (203) is driven by the rotary rod (208) to rotate under the drive of the rotary motor (207), and the vacuum pipeline of the vacuum suction cup (203) is connected with the vacuum pump (209); The cleaning chamber exhaust pipe (204) is used to discharge the gaseous products produced in the cleaning process; The cleaning chamber liquid sump (205) is located at the bottom of the cleaning chamber (2), and is used to collect liquid products produced during the cleaning process; The cleaning chamber drain pipe (206) is used to discharge the liquid product enriched in the liquid sump of the cleaning chamber. 6. supercritical water jet cleaning equipment according to claim 1, is characterized in that, described cleaning product recovery treatment device (3) comprises cleaning liquid recovery tank, is used to collect the liquid that discharges from cleaning chamber (2), and The impurity removal and purification treatment is performed on the liquid.

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