CN102339773A

CN102339773A - Method for judging etching ending point through valve opening

Info

Publication number: CN102339773A
Application number: CN2010102387114A
Authority: CN
Inventors: 林英浩
Original assignee: Piotech Shenyang Co Ltd
Current assignee: Piotech Inc
Priority date: 2010-07-28
Filing date: 2010-07-28
Publication date: 2012-02-01

Abstract

The invention relates to the field of plasma-enhanced chemical vapor deposition (PECVD) equipment etching, in particular to a method for judging an etching ending point through valve opening. The method is used for judging washing finish when a cavity of PECVD equipment is washed through etching. The method is characterized in that the cavity, the etching ending point of which needs to be judged, is communicated with an exhaust duct; the exhaust duct is provided with a valve; the etching ending point is judged through the opening of the valve on the exhaust duct; and during etching, the pressure is constant and the etching ending point is judged through the opening of the valve on the exhaust duct. The method has the following beneficial effects: the method is simple and convenient and has high reliability; and the problems such as higher cost in the prior art are solved by adopting the method.

Description

A kind of method of judging the etching terminating point through valve opening

Technical field

The present invention relates to PECVD equipment etching field, be specially a kind of method through valve opening judgement etching terminating point, it is when PECVD equipment carries out the cleaning of cavity etching, judges the method for accomplishing of cleaning.

Background technology

Lithographic technique (etching technique) is in semiconductor technology, the technology of semiconductor substrate surface or surface coverage film being carried out selective corrosion or peeling off according to mask graph or designing requirement.

The etching of PECVD equipment is cleaned and is referred to: after PECVD equipment carries out deposit film technology, have thin film deposition to the component surface of cavity inner wall and cavity the inside, when film accumulates when too much, can be shed on the wafer, have a strong impact on thin-film technique.So need before film comes off, their methods with etching be washed.

Etching cleaning process: aerating oxygen, C in cavity ₂F ₆, open radio frequency, make to produce plasma in the cavity, thereby chemical reaction takes place, make the film on the parts of cavity inner wall and cavity the inside generate gas, drain.

In the prior art, judge that the method for etching terminating point mainly contains: emission spectrometry, infra-red sepectrometry, RF voltage monitoring method, mass spectrometer method etc., wherein:

(1) shortcoming of emission spectrometry: cavity needs perforate, increases cost and processed complex property; Etching need adopt aura etching in the cavity when cleaning, and the aura etching progressively is eliminated.

(2) shortcoming of infra-red sepectrometry: cost is high, and very strong patent limitation (US6191864, US6228277, US6582618, US 6081334, US 5888337, US 5780315, US 5552016 and US6878214 etc.) is arranged; Transducer is dirty easily, influences accuracy.

(3) shortcoming of RF voltage monitoring method: etching need adopt aura etching in the cavity when cleaning, and the aura etching progressively is eliminated.

(4) shortcoming of mass spectrometer method: cost is high.

Summary of the invention

The object of the present invention is to provide a kind of method through valve opening judgement etching terminating point, the cost that exists in the solution prior art is than problems such as height.

Technical scheme of the present invention is:

A kind of method through valve opening judgement etching terminating point, the cavity that needs to judge the etching terminating point is communicated with discharge duct, and discharge duct is provided with valve, judges the etching terminating point through the aperture of valve on the discharge duct.

Described method through valve opening judgement etching terminating point, during etching, pressure is constant, judges the etching terminating point through the aperture of valve on the discharge duct.

Described method through valve opening judgement etching terminating point, pressure 3torr ± 0.1torr in the cavity; In the etching process, when the aperture of valve when 17% becomes 13%, etching is cleaned and is finished.

The invention has the beneficial effects as follows:

1, cost is low.In PECVD equipment; The valve of band aperture is necessary device, only needs the aperture of monitoring valve just can judge the terminating point that etching is cleaned, and need not increase hardware cost.

2, do not receive patent limitation.

3, reliability is high.Stablizing of pecvd process need be by the valve accuracy and reliable and stable assurance of band aperture.

Principle of the present invention is following:

When carrying out the etching cleaning in the cavity; The film generation chemical reaction of the gas that feeds under plasma state and in the chamber, this reaction are venting reactions, after the reaction end; If guarantee that the pressure in the chamber is constant, need reduce on the discharge duct aperture of valve and accomplish.

Description of drawings

Fig. 1 is the one embodiment of the invention sketch map.

Embodiment

As shown in Figure 1, the present invention need judge that the cavity 1 of etching terminating point is communicated with discharge duct 2, and discharge duct 2 is provided with valve 3.

Embodiment 1

As shown in Figure 1, carry out etching at PECVD equipment and clean in the cavity process, pressure remains unchanged in the cavity 1, through the aperture of valve 3 on the monitoring discharge duct 2, judges the method that the etching cleaning finishes.

In the etching flow process, technological parameter is following:

Oxygen flow: 1600sccm;

C ₂F ₆Flow: 1600sccm;

Pressure in the cavity: 3 holders (torr);

In the etching process, when the aperture of valve when 17% becomes 13%, etching is cleaned and is finished.

In the present embodiment, the controller of employing valve can be monitored the aperture of valve.

After adopting present embodiment to judge that etching stops, test data is following:

Table 1

The aperture of valve	The endovascular thin film situation	The etching progress
			17％	Cavity wall has film (color of wall)	Beginning
16%-14% (changing continuously)	The cavity wall color gradually changes	Etching is carried out
			13％	Color disappears, and becomes the color of chamber wall material	Etching finishes

Claims

1. one kind is passed through the method that valve opening is judged the etching terminating point, it is characterized in that: needs judge that the cavity of etching terminating point is communicated with discharge duct, and discharge duct is provided with valve, judges the etching terminating point through the aperture of valve on the discharge duct.

2. according to the described method through valve opening judgement etching terminating point of claim 1, it is characterized in that: during etching, pressure is constant, judges the etching terminating point through the aperture of valve on the discharge duct.

3. according to the described method of claim 2, it is characterized in that: pressure 3torr ± 0.1torr in the cavity through valve opening judgement etching terminating point; In the etching process, when the aperture of valve when 17% becomes 13%, etching is cleaned and is finished.