Mass production of silicon dioxide film by liquid phase...

Details Mass production of silicon dioxide film by liquid phase... Mass production of silicon dioxide film by liquid phase...

1999-04-29

2001-03-06

Chaudhuri, Olik (Department: 2814)

Single-crystal, oriented-crystal, and epitaxy growth processes;

Processes of growth from liquid or supercritical state

Liquid phase epitaxial growth

C117S054000, C117S020000, C414S936000, C438S787000

Reexamination Certificate

active

06197110

ABSTRACT:

FIELD OF THE INVENTION
The present invention demonstrates a method of mass production technology of liquid phase deposition for the growth of silicon dioxide film (LPD-SiO
2
). Said invention comprising a deposition system for mass production, which is “two wafers held vertically in a slotted Teflon (a polytetrafluroethylene polymer such as polymers and copolymers of tetrafluroethylene) boat” with a “proper and short distance between wafers”.
BACKGROUND OF THE INVENTION
The application of silicon dioxide is widespread in integrated circuit (IC) fabrications;
(1) Silicon dioxide can be the gate oxide of metal-oxide semiconductor (MOS) devices;
(2) Silicon dioxide can be the field oxide to isolate itself from the other devices;
(3) Silicon dioxide can be the trench isolation;
(4) Silicon dioxide can be the masking for diffusion and ion implantation;
(5) Silicon dioxide can be the capping film to prevent losing impurity or composite atoms after annealing;
(6) Silicon dioxide can be the passivation film to protect the devices from the contamination of particles, dust and scratching, etc.
With the advancing development of technology, so far there are many ways of growing silicon dioxide film, such as: thermal oxidation or chemical vapor deposition (CVD). Gate oxide and field oxide are fabricated by thermal oxidation since thermal oxidation is the only way to produce high quality oxide film with low interface densities. However, these two technologies, thermal oxidation and CVD, have fabrication limitations in industrial applications including: the use of high temperatures (700° C.~1200° C.) during thermal oxidation that can easily result in the deformation of wafers and the damage to the device structure (due to the redistribution of dopants); and, in CVD, the drawbacks are its high equipment cost and growth temperature and need for more accurate control of the process conditions in mass production.
There are many ways of depositing silicon dioxide film at low temperature, such as: Plasma enhanced chemical vapor deposition (PECVD), Electron cyclotron resonance chemical vapor deposition (ECRCVD), etc. These depositions also need expensive system equipment and a growth temperature greater than 300° C. Therefore it's impossible to shorten the process flow by using photoresist as a mask. Such factors limit the flexibility of IC process design. According to the reports by H. Nagayama, et al. in
J. Electrochem. Soc.
, Vol. 135, pp. 2013 (1988) and A. Hishinuma, et al. in
Applied Surface Sci.
, Vol. 48/49, pp. 405 (1991), Liquid phase deposition (LPD-SiO
2
) is a recently developed method of growing a silicon dioxide film. Unlike the traditional technology of growing silicon dioxide film which needs high growth temperature and expensive system equipment, the growth temperature of this technology is very low (about 40° C.), and thus preferred for modem deep-submicron IC processes. However, so far there is no technology and method proposed for the mass production process of liquid phase deposition for the growth of silicon dioxide film (LPD-SiO
2
).
DESCRIPTION OF THE RELATED ART
Liquid phase deposition (LPD-SiO
2
) is the recently developed method of growing silicon dioxide films. The basic method includes adding boric acid into an aqueous solution of Hydrofluosilicic Acid (H
2
SiF
6
) such that the solution is supersaturated with silicon dioxide, and then immersing a semiconductor wafer in the aqueous solution so that silicon dioxide deposition can occur on the wafers having individual chip devices(abbreviated LPD-SiO
2
).
SUMMARY OF THE INVENTION
Unlike the traditional technology of depositing silicon dioxide film which needs high growth temperature and expensive system equipment, the growth temperature of the present invention is very low (about 40° C.), and also LPD-SiO
2
film has very good selectivity to the growth substrate. The advantages of LPD-SiO
2
can be summarized as follows:
(1) LPD-SiO
2
can deposit a uniform and high density silicon dioxide film.
(2) The growth temperature of the present invention is very low, thus the effect of high temperature to the wafers in the process can be eliminated.
(3) System equipment is cheap and simple.
(4) LPD-SiO
2
is selective to the photoresist, thereby IC processes can be simplified.
Since LPD-SiO
2
is suitable for IC fabrication, the key point of whether LPD-SiO
2
can be applied in IC processes depends on whether this technology can be used in mass production. However, so far there has been no in depth research or concrete methods proposed for a mass production process using liquid phase deposition for the growth of a silicon dioxide film (LPD-SiO
2
).
The present invention proposes an effective method of applying LPD-SiO
2
technology in mass production. The present invention comprises a method of LPD-SiO
2
deposition which includes “two wafers held vertically in a slotted Teflon boat” with a “proper and short distance between wafers” such that LPD-SiO
2
technology can be applied even more widely.
The present invention enables LPD-SiO
2
technology mass production. The present invention comprises one method: “two wafers held vertically in a slotted Teflon boat” with a “proper and short distance between wafers” and “symmetry” for the mass production of wafer growth.


REFERENCES:
patent: 5314107 (1994-05-01), d'Aragona et al.
patent: 5920780 (1999-07-01), Wu
Hirotsugu Nagayama, Hisao Honda and Hideo Kawahara; “A New Process for Silica Coating”; Nippon Sheet Glass Company, Limited, Central Research Laboratory, Itami 664, Japan; Aug. 1988.
Akihiro Hishinuma, Takuji Goda, Masaki Kitaoka, Shigeo Hayashi and Hideo Kawahara; “Formation of silicon dioxide films in acidic solutions”; Central Rsearch Laboratory, Nippon Sheet Glass Co., Ltd., Konoike, Itami, Hyogo, Japan; 1991—Elsevier Science Publishers B.V. (North-Holland); Aug. 1990.

Affiliated with

Also associated with

Rating

Mass production of silicon dioxide film by liquid phase... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Mass production of silicon dioxide film by liquid phase..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mass production of silicon dioxide film by liquid phase... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2515248