CN1850361A

CN1850361A - Washing method for removing polymer film adhered on quartz pant surface

Info

Publication number: CN1850361A
Application number: CN 200510126270
Authority: CN
Inventors: 陶林
Original assignee: Beijing North Microelectronics Co Ltd
Current assignee: Beijing North Microelectronics Co Ltd
Priority date: 2005-12-02
Filing date: 2005-12-02
Publication date: 2006-10-25
Anticipated expiration: 2025-12-02
Also published as: CN100509186C

Abstract

The present invention provides a washing method for removing polymer film adhered on quartz part surface. It includes the following steps: soaking in chemical solution, coarse washing and fine washing.

Description

A kind of removal is attached to the cleaning method of quartz parts surface thin polymer film

Technical field

The present invention relates to polycrystalline silicon etching process, relate to the cleaning method that a kind of removal is attached to the quartz parts surface thin polymer film particularly.

Background technology

In traditional semiconductor polycrystal silicon gate dry etch process, the carrying out along with reaction can produce a lot of accessory substances.A series of division polymerisation, the polymer of generating structure complexity can take place in these accessory substances under the process environments of reative cell.The part of these polymer can be discharged reative cell by molecular pump and dried pump with the air-flow of reative cell, and another part can be attached on the reaction chamber wall.Can constantly accumulate along with the continuation of technology attached to the polymer film on the inwall, this layer film stability is not strong, may split away off and pollutes silicon chip from inwall at any time, so need the part that be exposed in the reative cell in the process environments regularly be cleaned.

The main etching agent that uses in the general polycrystalline silicon etching process comprises Cl ₂, HBr, O ₂With some fluoro-gas, through with the reaction of Si after, the main component of the thin polymer film of generation is the mixture that contains elements such as Cl, Si, O, Br, complex structure.Common cleaning means are to use H earlier ₂SO ₄Soak, clean with HF solution and deionized water then.Because the characteristic of quartzy part itself is different with other metal parts, this method can be damaged quartzy sheet material to a certain extent when removing polymer, and undesirable for the polymer cleaning performance, consuming time longer.

Summary of the invention

(1) technical problem that will solve

The purpose of this invention is to provide the cleaning method that a kind of effective removal is attached to the quartz parts surface thin polymer film.

(2) technical scheme

Cleaning method of the present invention comprises that chemical liquids is soaked, ultra-pure water is slightly washed and three steps of deionized water fine purifiation.During cleaning, quartzy part is separately cleaned with other metal parts.

After quartzy part taken off from etching apparatus, with the clear water flushing, use isopropyl alcohol (IPA) flushing then earlier, with the clear water flushing, remove grease with the acetone wiping at last again.

Then, with hydrogen peroxide/ammoniacal liquor mixed solution (NH ₄OH: H ₂O ₂: H ₂O=1: 1: 2～4) soak, use hydrochloric acid (HCl: H again ₂O=1: 5～10) soak, use nitric acid/hydrofluoric acid mixed solution (HNO at last ₃: HF: H ₂O=5: 1: 40～50) soak.

After immersion is finished, part is put into the 25kHz ultrasonic tank slightly wash, cleaning fluid is a ultra-pure water.

Then, part is put into the 40kHz ultrasonic tank carry out fine purifiation, cleaning fluid is a deionized water.

If still have residue, available solution (HNO ₃: HF: H ₂O=1: 1: 10～30) wiping, every wiping is once flushing of circle water and wiping.The wiping number of times is too much unsuitable, in order to avoid the infringement coating.

Water flushing and wiping again, N ₂Dry up.

At last, part is placed 110～120 ℃ of baking ovens dried by the fire 1.5～2.5 hours.

(3) beneficial effect

Cleaning method of the present invention is simple to operate, and is consuming time few, and the cleaning performance ideal is little to the quartz damage.

The specific embodiment

Following examples are used to illustrate the present invention, but are not used for limiting the scope of the invention.

Embodiment 1

After quartzy part taken off from etching apparatus, water flushing immediately 20 minutes, wiping does not have color until non-dust cloth.Then, there is not color until non-dust cloth with IPA wiping 10 minutes repeatedly.There is not color with the acetone wiping until non-dust cloth again.Water washes and N then ₂Dry up.

Quartzy part is put into solution (NH ₄OH: H ₂O ₂: H ₂O=1: 1: 2) soaked 20 minutes in, constantly stir solution, water flushing and N ₂Dry up; Again quartzy part is put into solution (HCl: H ₂O=1: soaked 20 minutes water flushing and wiping 5); At last quartzy part is put into solution (HNO ₃: HF: H ₂O=5: 1: 40) soaked 20 minutes water flushing and wiping in.

After immersion is finished, part is put into the 25kHz ultrasonic tank slightly to be washed, ultrasonic 20 minutes, the ultra-pure water water temperature is 50 ℃, ultrasonic energy density is 20 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

After slightly washing, part is put into the 40kHz ultrasonic tank carry out fine purifiation, ultrasonic 20 minutes, 18,000,000 deionized water water temperatures are 50 ℃, ultrasonic energy density is 20 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

If still have residue, available solution (HNO ₃: HF: H ₂O=1: 1: 10) wiping, every wiping is once flushing of circle water and wiping.

Water flushing and wiping again, N ₂Dry up.

At last, part is placed 115 ℃ of baking oven bakings 2 hours.

After the cleaning, quartz parts surface recovers cleaning.Use the surface particles detector to detect, piece surface particle situation conforms to quality requirements; The use surfagauge is tested, and changes not quite before and after Part Surface Roughness is cleaned, and shows that the cleaning damage is less.Whole cleaning process saves time than conventional method.

Embodiment 2

After quartzy part taken off from etching apparatus, water flushing immediately 30 minutes, wiping does not have color until non-dust cloth.Then, there is not color until non-dust cloth with IPA wiping 5 minutes repeatedly.There is not color with the acetone wiping until non-dust cloth again.Water washes and N then ₂Dry up.

Quartzy part is put into solution (NH ₄OH: H ₂O ₂: H ₂O=1: 1: 4) soaked 30 minutes in, constantly stir solution, water flushing and N ₂Dry up; Again quartzy part is put into solution (HCl: H ₂O=1: soaked 30 minutes water flushing and wiping 10); At last quartzy part is put into solution (HNO ₃: HF: H ₂O=5: 1: 50) soaked 30 minutes water flushing and wiping in.

After immersion is finished, part is put into the 25kHz ultrasonic tank slightly to be washed, ultrasonic 30 minutes, the ultra-pure water water temperature is 50 ℃, ultrasonic energy density is 15 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

After slightly washing, part is put into the 40kHz ultrasonic tank carry out fine purifiation, ultrasonic 30 minutes, 18,000,000 deionized water water temperatures are 50 ℃, ultrasonic energy density is 15 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

If still have residue, available solution (HNO ₃: HF: H ₂O=1: 1: 30) wiping, every wiping is once flushing of circle water and wiping.。

Water flushing and wiping again, N ₂Dry up.

At last part is placed 120 ℃ of baking oven bakings 1.5 hours.

Embodiment 3

After quartzy part taken off from etching apparatus, water flushing immediately 25 minutes, wiping does not have color until non-dust cloth.Then, there is not color until non-dust cloth with IPA wiping 8 minutes repeatedly.There is not color with the acetone wiping until non-dust cloth again.Water washes and N then ₂Dry up.

Quartzy part is put into solution (NH ₄OH: H ₂O ₂: H ₂O=1: 1: 4) soaked 25 minutes in, constantly stir solution, water flushing and N ₂Dry up; Again quartzy part is put into solution (HCl: H ₂O=1: soaked 25 minutes water flushing and wiping 10); At last quartzy part is put into solution (HNO ₃: HF: H ₂O=5: 1: 50) soaked 30 minutes water flushing and wiping in.

After immersion is finished, part is put into the 25kHz ultrasonic tank slightly to be washed, ultrasonic 25 minutes, the ultra-pure water water temperature is 50 ℃, ultrasonic energy density is 25 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

After slightly washing, part is put into the 40kHz ultrasonic tank carry out fine purifiation, ultrasonic 25 minutes, 18,000,000 deionized water water temperatures are 50 ℃, ultrasonic energy density is 25 watts/gallon, be lined with non-dust cloth between part and the supporting plate to prevent the water seal, quartzy part surface faces up to one of reative cell inside, to guarantee the smooth smooth of surface.

If still have residue, available solution (HNO ₃: HF: H ₂O=1: 1: 20) wiping, every wiping is once flushing of circle water and wiping.

Water flushing and wiping again, N ₂Dry up.

At last part is placed 110 ℃ of baking oven bakings 2.5 hours.

Claims

1, a kind of removal is attached to the cleaning method of quartz parts surface thin polymer film, and it comprises the following steps:

A. chemical liquids is soaked;

B. slightly wash;

C. fine purifiation.

2, cleaning method as claimed in claim 1 is characterized in that the chemical liquids of using in the soaking step is followed successively by: hydrogen peroxide/ammoniacal liquor mixed solution, hydrochloric acid, nitric acid/hydrofluoric acid mixed solution.

3, cleaning method as claimed in claim 1, it is characterized in that slightly washing the used cleaning fluid of step is ultra-pure water, and ultrasonic energy density is 15-25 watt/gallon.

4, cleaning method as claimed in claim 1 it is characterized in that the used cleaning fluid of fine purifiation step is a deionized water, and ultrasonic energy density is 15-25 watt/gallon.