CN1570221A

CN1570221A - Method for etching electrolytic mask chromium film

Info

Publication number: CN1570221A
Application number: CN 03141695
Authority: CN
Inventors: 唐光亚
Original assignee: Semiconductor Manufacturing International Shanghai Corp
Current assignee: Semiconductor Manufacturing International Shanghai Corp; Semiconductor Manufacturing International Corp
Priority date: 2003-07-18
Filing date: 2003-07-18
Publication date: 2005-01-26

Abstract

The invention provides an etching method for the electrolytic mask chromium film. The method comprises the following steps: forming a chromium film on the substrate; forming a pattern photoresistive mask on the film and obtaining a device to be etched; placing the device to be etched in an electrolytic solution; connecting the film with the positive electrode of a power supply; connecting the electrolytic solution with the negative electrode of the power supply; carrying out the electrolytic reaction; taking the device to be etched out from the electrolytic solution.

Description

The etch process method of electrolyzing mask chromium film

Technical field

The present invention relates to a kind of etch process method, particularly a kind of in electrolytic mode, the etch process method of enforcement mask chromium film.

Background technology

Form mask (mask) afterwards via lithography (lithography), need carry out optionally etching or ion and implant by etching to film under the photoresistance or substrate.

The etching technique that is widely used in manufacture of semiconductor now mainly contains two kinds: the one, and Wet-type etching (wetetching); Another is dry-etching (dry etching).Before a kind of mainly be to utilize chemical reaction to carry out the etching of film; The latter then utilizes and carries out etching near the effect of physics.

So-called " Wet-type etching " is to utilize diffusional effect (diffusion), and with the reactant in the etching solution, by one deck frictional belt (boundary layer) as thin as a wafer, to arrive the surface of etched film.Produce chemical reaction through the molecule of this reactant and film surface, and generate all cpds, after those resultants via diffusional effect by the frictional belt in solution, then be discharged from solution.This kind carried out removing of film molecule by liquid state or gasiform resultant, therefore do not have fixed directivity, and promptly so-called " isotropic etching " (isotrophic).The selectivity of this Wet-type etching is preferable.So-called " selectivity (selectivity) " is meant in the etch process rate of etch ratio for etched film and other materials (for example photoresistance and substrate).On behalf of etching, the selectivity height mostly carry out on etched material.Because Wet-type etching is to carry out etching with chemical mode, can be by judgement for solution properties, and mostly only adopt the etched solution of etch thin film, therefore, its selectivity is higher.But, " undercutting (undercut) phenomenon " during solution etching excessive concentration, also can take place, so-called " undercut phenomenon " as shown in Figure 1, is under isotropic etching, causes the beneath film partly of photoresistance to be etched.Simultaneously, because isotropic etching, and lower time micron uncertainty that pattern (pattern) is provided with.

So-called " dry-etching " is the technology of carrying out film etching with electricity slurry (plasma).Impose voltage for gas in the container of low-pressure state, making originally, neutral gas molecule is excited or is dissociated into various charged ion (charged ion), atomic group (radicals), molecule and electronics.The composition of these a little examples just is called the electricity slurry.The electricity slurry is the collapse state of gas molecule, and this can transmit electric current as a conductor.To treat the etching body, be arranged at the connection negative electrode, and make the potential difference between electricity slurry and battery lead plate, the accelerated band positive charge ion, and the surface of bombardment battery lead plate splashes (sputtering) phenomenon with formation.This dry etching mode for vertical etch capabilities much larger than the lateral etches ability, so its have splendid anisotropic (anisotrophic) (near 90 the degree), as shown in Figure 2.And,,, therefore higher reliability is arranged because preferable " anisotropic " arranged for the setting of inferior micron pattern.But owing to the surface by charge ion " simultaneously " bombardment battery lead plate, therefore, etched film and other materials (for example photoresistance and substrate) are banged promptly simultaneously, and make selectivity relatively poor.And, relatively poor in the control of flaw.

Summary of the invention

Purpose of the present invention, in the shortcoming that solves above-mentioned known wet etching and dry etching, by the electrolytic technology of employing, and for giving etched manufacturing method thereof with the made mask of chromium material.

The present invention adopts the electrolysis tech of technology maturation, by the molecular melting technology is applied to the mask etch process, and obtain effects such as " enforcement of inferior micron pattern, preferable pattern reliability and preferable important sizes (Critical dimension) " with the same effect of dry etching, in addition, and can have preferable defect control.

Description of drawings

Fig. 1 is the cross-sectional view of the undercut phenomenon that takes place of known wet etching;

Fig. 2 is the cross-sectional view of the anisotropic etching of known dry etching;

Fig. 3 is the first step of the etch process method of electrolyzing mask chromium film of the present invention;

Fig. 4 is second step of the etch process method of electrolyzing mask chromium film of the present invention; And

Fig. 5 is the third step of the etch process method of electrolyzing mask chromium film of the present invention.

Embodiment

The etch process method of electrolyzing mask chromium film provided by the invention comprises following steps:

In substrate, form the film of a chromium membrane material;

On film, form the pattern photo-resistive mask and constitute and treat etching system;

This is treated the heavy electrolytic solution that places of etching system;

The positive pole of this film and a power supply is electrically contacted;

This electrolytic solution is contacted with the negative electricity of this power supply;

Implement electrolytic reaction; And

This is treated that etching system takes out in this electrolytic solution.

In above-mentioned etch process method, the part that this film and positive source electrically contact is for treating the ora terminalis part of etching system at this.

In above-mentioned etch process method, be somebody's turn to do the power cathode that electrically contacts with electrolytic solution, directly do not electrically contact with treating etching system.

Below, with reference to figure 3 to Fig. 5 embodiments of the present invention are described.

As shown in Figure 3, be the formation for the treatment of etching system 1; At first on substrate 2, by physical vapor deposition (physical vapor deposition; PVD) or chemical vapour deposition (Chemical VaporDeposition; CVD), form a chromium film 3; Afterwards, by the suitable pattern transfer (patterntransfer) of lithography, and form photo-resistive mask 4.

In Fig. 4, to treat that etching system 1 places container 7, fill up among the electrolytic solution 6, with connect with the mains 5 positive pole 8 of the edge contact point of chromium film 2 and this is treated that etching system 1 is inserted, the negative pole of power supply 5 then contacts with electrolytic solution, but does not directly contact with treating etching system 1.

In Fig. 5, via electrolytic reaction, and the film that will treat the photo-resistive mask of etching system 1 and not cover photo-resistive mask is partly removed, and only stays film that original photo-resistive mask covers partly.

Claims

1, a kind of etch process method of electrolyzing mask chromium film comprises following steps:

In substrate, form the film of a chromium membrane material;

This is treated the heavy electrolytic solution that places of etching system;

The positive pole of this film and a power supply is electrically contacted;

Implement electrolytic reaction; And

This is treated that etching system takes out in this electrolytic solution.

2, etch process method as claimed in claim 1 is characterized in that, the part that this film and positive source electrically contact is for treating the ora terminalis part of etching system at this.

3, etch process method as claimed in claim 1 is characterized in that, is somebody's turn to do the power cathode that electrically contacts with electrolytic solution, does not directly electrically contact with treating etching system.