Methods for dry etching at low substrate temperatures using...

Details Methods for dry etching at low substrate temperatures using... Methods for dry etching at low substrate temperatures using...

2002-05-16

2004-03-30

Whitehead, Jr., Carl (Department: 2813)

Semiconductor device manufacturing: process

Coating with electrically or thermally conductive material

To form ohmic contact to semiconductive material

C438S715000, C438S723000, C438S738000, C216S067000

Reexamination Certificate

active

06713380

ABSTRACT:

Applicant hereby incorporates by reference Japanese Application No. 2001-146393 (P), filed May 16, 2001, in its entirety.
TECHNICAL FIELD
The present invention relates to etching methods, apparatus and methods for fabricating a semiconductor device. More particularly, the present invention includes certain embodiments relating to etching methods, apparatus and methods for fabricating a semiconductor device, which improve an etching selection ratio of a film to be etched against metal silicide, Si, and photoresist.
RELATED ART
In conventional dry-etching methods, a plasma of halogen gas is generated in a processing chamber, and the action of ions, radicals and electrons in the plasma are used to conduct an etching. These methods are known as plasma etching methods.
Many proposals have been made to increase the etching speed while improving the etching selectivity in such etching methods. For example, as one of the etching methods to increase the etching speed at the time of etching silicon and silicon oxide while decreasing the etching speed for photoresist, a method has been proposed in which fluorocarbon etching gas such as CHF
3
and the like is used, and the substrate temperature is controlled to be below zero degrees Centigrade when the etching is conducted. This method is advantageous when etching of a Si film or a Si substrate and etching of a SiO
2
film are to be conducted at the same time.
Also, in another proposed method to increase the etching speed for Si and to slow down the etching speed for SiO
2
and photoresist, SF
6
is used as etching gas, and the substrate temperature is controlled to be −100 to 130° C. when the etching is conducted (see Monthly Semiconductor World 1998, 1, p58). This method is advantageous when a SiO
2
film is not etched, but only a Si film or a Si substrate is to be etched.
SUMMARY
Certain embodiments relate to an etching method including supplying etching gas onto a member to be processed, and forming a plasma in at least part of the etching gas for etching the member to be processed by the plasma. The etching method includes maintaining the member to be processed at temperatures of 30° C. or lower when etching is conducted, and using gas including a fluorocarbon gas and at least one of O
2
gas and O
3
gas as the etching gas.
Embodiments also relate to an etching apparatus for etching a member to be processed by plasma, including a maintaining system that cools and maintains the member to be processed at temperatures of 30° C. or lower when etching is conducted, a supply system that supplies etching gas onto the member to be processed, and a plasma system that forms a plasma in at least part of the etching gas supplied by the supply system. A gas including a fluorocarbon gas and at least one of O
2
gas and O
3
gas is used as the etching gas.
Embodiments also relate to a method for fabricating a semiconductor device, the method including forming a dielectric film on a base comprising at least one material selected from the group of a metal silicide and Si. The method also includes dry-etching the dielectric film to form in the dielectric film first and second contact holes that expose surfaces of the base. The amount of etching in forming the first contact hole is less than the amount of etching in forming the second contact hole. The etching gas used for the dry-etching is gas includes a fluorocarbon gas and at least one of O
2
gas and O
3
gas. The temperature of the base is 30° C. or lower when the dry-etching is conducted.
Embodiments also relate to a method for fabricating a semiconductor device, the method including forming a gate electrode on a semiconductor substrate, forming diffusion layers in source/drain regions of the semiconductor substrate, and forming a metal silicide film on the gate electrode and the diffusion layers of source/drain regions. The method also includes forming a silicon oxide film on the metal silicide film. The method also includes dry-etching the silicon oxide film to form in the silicon oxide film a first contact hole located over the gate electrode, and second contact holes located over the diffusing layers in the source/drain regions. The etching gas used for the dry-etching is gas including a fluorocarbon gas and at least one of O
2
gas and O
3
gas, and the temperature of the semiconductor substrate is 30° C. or lower when the dry-etching is conducted.


REFERENCES:
patent: 4207137 (1980-06-01), Tretola
patent: 4751191 (1988-06-01), Gonsiorawski et al.
patent: 5411624 (1995-05-01), Hirano et al.
patent: 5660671 (1997-08-01), Harada et al.
patent: 5785877 (1998-07-01), Sato et al.
patent: 5865938 (1999-02-01), Peeters et al.
patent: 5906948 (1999-05-01), Liu et al.
patent: 5922622 (1999-07-01), Lee et al.
patent: 6046478 (2000-04-01), Klein
patent: 6254683 (2001-07-01), Matsuda et al.
patent: 6340632 (2002-01-01), Fukada et al.
patent: 6355518 (2002-03-01), Wu et al.
patent: 6451708 (2002-09-01), Ha
patent: 2002/0158339 (2002-10-01), Yamamoto
patent: 2002/0182880 (2002-12-01), Zhu et al.
patent: 2000-349150 (2000-12-01), None
“Etching of Si at Low Temperature by Hitachi—Improved Anisotropy and Selectivity, and Satisfactory Speed,” Semiconductor World, vol. 7, No. 1, pp. 58-59 (1988).*
article in Monthly Semiconductor World 1998, vol. 1, pp. 58-63 (1998).

Affiliated with

Also associated with

Rating

Methods for dry etching at low substrate temperatures using... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Methods for dry etching at low substrate temperatures using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for dry etching at low substrate temperatures using... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3194336