JP2005064443A - Substrate treatment method and substrate treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely and completely remove resists of a wafer or the like while also eliminating contamination, and to suppress metal contamination, particle generation and watermarking. <P>SOLUTION: By using the substrate treatment apparatus or the like comprising: a support substrate 101 for holding a wafer W; a heater part 102 for controlling heating to the support substrate; and an ashing treatment part composed of a mechanism for sprinkling ozone gases 106 and ozone water 107 over the surface of the wafer W from a sprinkler part 103 connected through piping 104 and 105, and a discharge 109 discharged by passing the gases and the water supplied from the sprinkler part 103 through piping 108, an ozone water treatment is applied to a resist film formed on the wafer or the like sequentially after an ozone gas treatment, thereby safely and completely removing the resists while also eliminating contamination, and suppressing the metal contamination, particle generation and watermarking. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a substrate processing method and a substrate processing apparatus. More specifically, for example, a substrate to be processed such as a semiconductor wafer or a glass substrate for LCD is accommodated in a processing container, and a processing gas is formed on the surface of the substrate to be processed. Substrate processing method for sequentially supplying resist removal processing, removal processing of contaminants, impurities, etc., and drying processing, etc. by sequentially supplying ozone gas, ozone water, etching solution, cleaning water, drying gas, etc. And a substrate processing apparatus.

In general, in a semiconductor device manufacturing process, a resist is applied to a semiconductor wafer or an LCD substrate (hereinafter referred to as a wafer) as a substrate to be processed, and a circuit pattern is reduced and transferred to the resist using a photolithography technique. This is developed, and then subjected to wafer process such as etching and impurity introduction, and then the resist is removed from the wafer, followed by removal of contaminants and impurities, followed by cleaning and drying. A series of processes such as performing In particular, the resist removal process in which polymerization has progressed by performing dry etching or ion implantation is an important process from the viewpoint of yield.

An example of the above processing will be described with reference to FIG. 9 in the case where the substrate to be processed is, for example, a silicon wafer. First, an oxide film OX is formed on the surface of a silicon wafer W (hereinafter referred to as wafer W) {see FIG. 9A}. Next, a resist is applied to the surface of the oxide film OX to form a resist pattern RP {see FIG. 9B}. Next, an unnecessary oxide film is etched using a chemical solution called DHF (HF / H ₂ O), BHF, and then an ion implantation layer II is formed by ion implantation treatment {see FIG. 9C. }. Thereafter, an unnecessary resist is removed using a chemical solution (sulfuric acid / hydrogen peroxide solution) called SPM (mixed solution of H ₂ SO ₄ / H ₂ O ₂ ) {see FIG. 9D}.

In the conventional apparatus used as a means for removing the resist, it is generally filled with a chemical solution such as SPM (mixed solution of H ₂ SO ₄ / H ₂ O ₂ ) (sulfuric acid / hydrogen peroxide) and heated to 80 ° C. to 130 ° C. The wafer is immersed in the washed tank, and the resist, particularly the resist that has been polymerized by dry treatment such as ion implantation or plasma etching, is also stripped.

However, if a heated chemical solution such as sulfuric acid / hydrogen peroxide is used in the resist removal step, sulfate ions remain on the surface of the wafer W after the resist is removed, and the remaining sulfate ions cause generation of particles and contamination. There is a risk of inviting. Furthermore, the use of heated hot sulfuric acid has a problem of high work and management risks.

On the other hand, in recent years, it has been demanded to remove the resist using ozone (O ₃ ), which can be easily treated and managed from the viewpoint of environmental protection and safety. In this case, by exposing the wafer or the like to ozone gas or an ozone-dissolved solution, the resist or the like is oxidized by oxygen atom radicals or the like to be decomposed into carbon dioxide or water.

However, there has been a problem that resist film removal by conventional ozone gas or ozone-dissolved solution, that is, so-called ashing treatment, has not achieved sufficient removal of the resist film. In particular, there has been a serious problem that the removal of the resist film that has undergone polymerization by ion implantation or plasma treatment has not been sufficiently achieved.

Further, when ozone treatment is performed, there is a risk of causing metal contamination or unnecessary growth of a chemical oxide film on the surface of a wafer or the like.

The present invention has been made in view of the above circumstances, and it is possible to completely remove even a resist, particularly a polymerized resist, by suppressing metal contamination of a wafer or the like, generation of particles, and growth of an oxide film. An object of the present invention is to provide a method and a substrate processing apparatus.

In order to solve the above-mentioned problems and achieve the above-mentioned object, the invention according to claim 1 supplies high-concentration ozone gas while heat-treating a substrate to be processed housed in a processing container in a nitrogen gas-based processing apparatus. It has the 1st process and the 2nd process of controlling temperature, supplying high concentration ozone water continuously.

The invention described in claim 2 is characterized in that a resist film is formed on the substrate shown in claim 1, and the substrate processing is removal processing of the resist film, so-called ashing processing.

The invention according to claim 3 is the first step heat treatment shown in claim 1, which is a gradient temperature raising process for supplying high-concentration ozone gas while raising the temperature from room temperature to about 250 ° C. in about 20 seconds. Yes, the temperature control in the second process is a temperature control process that performs gradient cooling from about 250 ° C. to about 80 ° C. in about 10 seconds while supplying high-concentration ozone water after the gradient temperature processing in the first step. It is characterized by being.

The invention according to claim 4 is characterized in that the ozone concentration in the high-concentration ozone gas shown in claim 1 is 15% to 100%, and the ozone concentration in the high-concentration ozone water is 30 ppm or more. .

According to a fifth aspect of the present invention, the substrate to be processed that has undergone the substrate processing according to any one of the first to fourth aspects is transferred to another processing vessel, and the oxide formed on the substrate to be processed is removed by etching. A rinsing step of supplying a rinsing liquid to the substrate to be processed to clean the surface of the substrate to be processed; and a drying step of supplying a dry gas to the substrate to be processed to remove moisture adhering to the surface of the substrate to be processed. It is characterized by having.

According to a sixth aspect of the present invention, a substrate to be processed that has undergone substrate processing in the sealed container according to any one of the first to fourth aspects is formed on the substrate to be processed through a transfer process to another processing container or the like. A step of etching and removing oxide and the like; a rinsing step of supplying a rinse liquid to the substrate to be processed to clean the surface of the substrate to be processed; and supplying a dry gas to the substrate to be processed to provide a surface of the substrate to be processed. And a drying step for removing adhering moisture.

As described above, according to the present invention, since it is configured as described above, the following effects can be obtained.

According to the first to fourth aspects of the present invention, there is an effect that even a resist that has been polymerized by ion implantation treatment or plasma treatment can be completely removed without contamination or danger by a chemical solution.

According to the fifth aspect of the present invention, in addition to the effect of completely removing the resist, there are effects of removing metal contamination and particles and suppressing the generation of watermarks.

According to the sixth aspect of the invention, in addition to the effect of completely removing the resist, there is an effect that it is possible to provide a highly productive apparatus having an effect of removing metal contamination and particles and an effect of suppressing the generation of watermarks.

Hereinafter, a substrate processing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of an essential part showing an example of a substrate processing apparatus according to the present invention.

The substrate processing apparatus includes a support substrate 101 that holds a wafer W, a heater unit 102 that controls heating of the support substrate, and a spray unit 103 in which ozone gas 106 and ozone water 107 are connected to the surface of the wafer W through pipes 104 and 105. The ashing processing unit is configured to include a mechanism for spraying from a gas and water and a discharge 109 that discharges gas and water supplied from the spraying unit 103 through a pipe 108.

FIG. 2 is a cross-sectional view of the main part showing another example of the substrate processing apparatus according to the present invention.

The substrate processing apparatus includes a support substrate 201 that holds the wafer W, a mechanism that applies rotation 202 to the support substrate, an etching solution such as dilute hydrofluoric acid (DHF: HF / H ₂ O), and a super A mechanism for spraying pure water (H ₂ O ₂ ) 206, nitrogen gas, or hot nitrogen gas 207 from a spray unit 203 connected through pipes 206 and 207, and a gas, water, and the like supplied from the spray unit 203 are connected to a pipe 208. An etching process, a cleaning process, and a drying process unit, which are constituted by the discharged matter 209 discharged through the.

FIG. 3 is a schematic plan view showing the main arrangement of an example of the substrate processing apparatus according to the present invention.

The substrate processing apparatus includes a main body 301, an ozonizer system 318 that generates ozone gas and ozone water. The main body 301 includes a processing system 302, a clean unit system 313, an exhaust system 314, a chemical system 315, an ozone system 316, and a control. A system 317 is arranged.

In the main body 301 of the substrate processing apparatus, an ashing unit 303 and a cleaning / drying unit 306 are arranged as a processing system 302, and a substrate cassette 309 includes a substrate cassette input unit 310, a substrate cassette output unit 311 and a transfer robot. A transfer unit 312 is arranged.

The ashing unit 303 is provided with a substrate support unit 305 for holding a substrate to be processed in a heating support base 304 having a built-in heater unit, and constitutes a reaction chamber for performing an ashing process.

The cleaning / drying unit 306 includes a support base 307 and a substrate support unit 305 that holds a substrate to be processed, and constitutes a cleaning processing chamber that performs etching and cleaning processing and a drying chamber that performs drying processing. Note that it is possible to configure the cleaning processing chamber and the drying processing chamber as a single unit, and it is also possible to configure two or more processing chambers including the cleaning processing chamber and the drying processing chamber as a single unit.

Below, the Example about the ashing process which concerns on the substrate processing method of this invention is described in detail.

FIG. 4 is a flowchart relating to a resist ashing process on a wafer on which a resist film is formed according to an example of the present invention. That is,
1. 1. Transfer wafer to reaction chamber 2. Reduce the pressure in the reaction chamber to 10 Torr. Ozone gas spray (almost simultaneously with the start of heating in 4)
・ Ozone concentration: 15% to 100% (100% ozone gas is due to evaporation from liquid ozone)
・ Processing time: About 20 seconds (gradient heating reaction)
-Reaction chamber pressure: controlled to about 800 Torr Start of heating (almost simultaneously with ozone gas spraying in 3 above)
・ Temperature rise time: Approximately 20 seconds (tilt heating)
・ Heating temperature: Controlled to about 250 ℃ ・ Spraying with ozone water (almost simultaneously with heating temperature change in 6 below)
・ Ozone concentration: 30ppm or more ・ Processing time: Approximately 10 seconds (gradient cooling reaction)
・ Flow rate of ozone water: 0.1 l / min ・ Pressure in reaction chamber: Normal pressure Heating temperature change (almost simultaneously with ozone water spraying in 5 above)
・ Heating temperature: Control at about 80 ℃ ・ Processing time: About 10 seconds ・ Cooling time: Within about 10 seconds (Inclined cooling by spraying ozone water at room temperature)

FIG. 5 shows the time transition of the substrate temperature, ozone gas spraying, ozone water spraying, and process chamber pressure in the sequence according to the flowchart showing one embodiment of the ashing process of the present invention shown in FIG. It is.

Below, the Example about the washing | cleaning process which concerns on the substrate processing method of this invention is described in detail.

FIG. 6 is a flowchart relating to the wafer cleaning process performed after the resist film is removed, showing an example of the present invention. That is,
6). 6. Transfer wafer to reaction chamber 7. Seal the reaction chamber. Dilute hydrofluoric acid treatment (oxide film etching treatment)
・ Hydrofluoric acid concentration: 0.1% to 0.3%
・ Flow rate: About 0.5 liters / minute ・ Time: Spraying for 10 to 20 seconds ・ Wafer rotation: 30 to 50 rpm
10. Ultrapure water treatment ・ Flow rate: about 2 liters / minute ・ Time: 30-50 seconds ・ Wafer rotation: 30-50 rpm
11. Clean nitrogen (N2) gas spray ・ Flow rate: About 0.5 liter / min ・ Time: 15-20 seconds ・ Wafer rotation: 30-50 rpm
・

Below, the Example about the drying process which concerns on the substrate processing method of this invention is described in detail.

FIG. 7 is a flowchart relating to the drying process performed after the wafer cleaning process performed after the resist film is removed, showing an example of the present invention. That is,
12 Drying treatment ・ Clean hot nitrogen (N2) gas spray ・ Nitrogen (N2) gas temperature: 160 ° C. (wafer temperature rise)
Wafer rotation / time: 2,000 rpm, 2-3 seconds Pressure-reduced purge drying ・ Pressurized pressure / time: 1.5 kg / cm 2 · 7 to 9 seconds • Depressurized force / time: 0.5 kg / cm 2 · 7 to 9 seconds • Room temperature N 2 purge: 1 cycle treatment Remove from processing chamber

FIG. 8 is a time transition of the pressurizing / depressurizing force of the nitrogen gas treatment showing an example of the pressurizing / depressurizing purge drying sequence in accordance with the flowchart showing one embodiment of the drying process of the present invention shown in FIG. That is, the supply of nitrogen (N2) gas through the pipe and the pressure reduction by the vacuum pump are repeated, and the pressure in the nitrogen (N2) atmosphere treatment chamber at normal pressure (about 1 kg / cm2) is increased to 1.5 kg / cm2. The pressure was increased to 5 to 6 seconds and held in the pressurized state for 2 to 3 seconds, and then the pressure was reduced to 0.5 kg / cm 2 in 5 to 6 seconds and held in the reduced pressure state for 2 to 3 seconds. After that, pressurization under reduced pressure purge drying is performed in which the pressure is raised in 5 to 6 seconds to return to the normal pressure state as one cycle.

Hereinafter, other embodiments according to the substrate processing method of the present invention will be described in detail.

In the ashing process of the first embodiment, a rotation of, for example, about 20 to 30 rpm or more may be applied to the processing substrate.

In the cleaning process of the second embodiment, a dilute hydrofluoric acid process was used for the etching process, but other etching and cleaning liquids such as ozone-added dilute hydrofluoric acid, ozone-added aqueous ammonia, and ozone-added dilute hydrochloric acid were used as the etchant. Also good.

The cleaning process of the second embodiment and the drying process of the third embodiment may be collectively performed in the same processing container, or each process may be divided in each processing container.

In the drying process of Example 3 described above, rotation may be applied to the substrate during the pressurizing / depressurizing purge drying process, and other drying methods such as Marangoni drying using isopropyl alcohol (IPA) other than the pressurizing / depressurizing purge drying are used. May be.

It is a schematic sectional drawing of the principal part which shows an example of the substrate processing apparatus which concerns on this invention. It is sectional drawing of the principal part which shows the other example of the substrate processing apparatus which concerns on this invention. It is a schematic plan view which shows the principal part arrangement | positioning of an example of the substrate processing apparatus concerning this invention. FIG. 4 is a flowchart relating to a resist ashing process on a wafer on which a resist film is formed according to an example of the present invention. The time transition of a substrate temperature, ozone gas spraying, ozone water spraying, and a process chamber pressure in the sequence according to the flowchart which showed one Example of the ashing process of this invention is shown. 6 is a flowchart relating to a wafer cleaning process performed after the resist film is removed according to an example of the present invention. It is a flowchart which concerns on the drying process performed after the wafer cleaning process performed after removing the resist film which shows an example of this invention. It is time transition of the pressurization force of the nitrogen gas process which shows an example of the sequence of the pressurization / decompression purge drying according to the flowchart which showed one Example of the drying process of this invention. It is a schematic sectional drawing explaining an example of the processing process of a wafer.

Explanation of symbols

W Semiconductor wafer (substrate to be processed)
101, 201, support substrate 102 heater unit 103, 203 spraying unit 104, 105, 108, 206, 207, 208 piping 106 ozone gas 107 ozone water 109, 209 discharge 202 rotation 206 etching solution, ultrapure water 207 nitrogen gas, hot Nitrogen gas 301: Main body 302: Processing system 303: Ashing unit 304: Heating support table 305: Substrate support unit 306: Cleaning / drying unit 307: Support table 308: Substrate support unit 309: Substrate transport unit 310: Substrate cassette input unit 311 : Substrate cassette output unit 312: substrate transfer unit 313: clean unit system 314: exhaust system 315: chemical system 316: ozone system 317: control system 318: ozonizer system (ozone gas, ozone water)

Claims (6)

  It has a first step of supplying high-concentration ozone gas while heat-treating a substrate to be processed contained in a processing container, and a second step of controlling temperature while supplying high-concentration ozone water. A substrate processing method.   2. A substrate processing method, wherein a resist film is formed on the substrate shown in claim 1, and the substrate processing is removal processing of the resist film, so-called ashing processing.   The heat treatment in the first step shown in claim 1 is a gradient temperature raising treatment for supplying high-concentration ozone gas while raising the temperature from room temperature to about 250 ° C. in about 20 seconds, and the temperature in the second step. The control is substrate processing characterized in that, after supplying the gradient ozone treatment in the first step, the substrate is characterized in that it is inclined and cooled from about 250 ° C. to about 80 ° C. in about 10 seconds while supplying high-concentration ozone water. Method.   2. The substrate processing method according to claim 1, wherein the ozone concentration in the high-concentration ozone gas is from 15% to 100%, and the ozone concentration in the high-concentration ozone water is 30 ppm or more.   A substrate to be processed that has undergone the substrate processing according to any one of claims 1 to 4 is transferred to another processing container, and a step of etching and removing oxides and the like formed on the substrate to be processed, and rinsing the substrate to be processed A substrate comprising: a rinsing step of supplying a liquid to clean a surface of a substrate to be processed; and a drying step of supplying a dry gas to the substrate to be processed to remove moisture adhering to the surface of the substrate to be processed. Processing method.   The substrate to be processed that has undergone the substrate processing in the sealed container according to any one of claims 1 to 4 is subjected to an etching removal process on the oxide or the like formed on the substrate to be processed through a transfer process to another processing container or the like. A rinsing step of supplying a rinsing liquid to the substrate to be processed to clean the surface of the substrate to be processed; and a drying step of supplying a dry gas to the substrate to be processed to remove moisture adhering to the surface of the substrate to be processed. And a substrate processing apparatus.

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