Semiconductor device manufacturing: process – Making device or circuit responsive to nonelectrical signal – Responsive to electromagnetic radiation
Reexamination Certificate
1996-09-27
2002-08-06
Mulpuri, Savitri (Department: 2812)
Semiconductor device manufacturing: process
Making device or circuit responsive to nonelectrical signal
Responsive to electromagnetic radiation
C438S075000
Reexamination Certificate
active
06429038
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a solid-state imaging (image pick-up) device and a method of manufacturing the same, and more particularly to a solid-state imaging device of the structure comprising color filter and a dyeing layer process in a color filter production process suitable when applied thereto.
The configuration of a conventional solid-state imaging device will now be described with reference to
FIGS. 3-5
. As shown in
FIG. 3
, this solid-state imaging device comprises: groups of pixels
51
to
53
two-dimensionally arranged on a semiconductor substrate; vertical CCD shift registers
54
to
56
respectively disposed between these groups of pixels
51
to
53
, and adapted for transferring, in a vertical direction, signal charges produced in the pixels after undergone photoelectric conversion and stored therein; a horizontal CCD register
57
adjacently disposed at the lower end portion of the vertical CCD shift registers
54
to
56
, and adapted for reading out, in a horizontal direction, signal charges of the vertical CCD shift registers
54
to
56
, and an output circuit
58
disposed at the terminating end of the horizontal CCD shift register
57
.
This solid-state imaging device is manufactured as follows. Initially, an insulating film
62
is formed on a semiconductor substrate
61
so as to include transfer electrodes
63
,
64
(see
FIG. 4C
) of the vertical CCD shift registers
54
to
56
to form light shielding films
65
on the insulating film
62
so that they are positioned immediately above the transfer electrodes
63
,
64
thereafter to form a protective film
66
so as to cover the light shielding films
65
. Then, a first color filter pattern
67
is formed on the protective film
66
. In this case, the first color filter pattern
67
is formed by coating resist for color filter onto the protective film
66
to carry out mask pattern transfer at a predetermined position with respect to the light shielding films
65
to implement the development processing thereto (FIG.
4
A).
Thereafter, similar process is carried out for a second time to respectively form a second color filter pattern
68
(
FIG. 4B
) and a third color filter pattern
69
(FIG.
4
C).
However, with the such conventional manufacturing method, the problem that the color picture characteristic is degraded took place.
Namely, there were instances where, as shown in
FIG. 5A
, e.g., the first color filter pattern
67
is positionally shifted to the left side with respect to the light shielding film
65
so that gap takes place between the first color filter pattern
67
and the light shielding film
65
of the right side. In such a case, any shift (difference from the ideal characteristic) takes place in the spectral characteristic by the dyeing (coloring) pattern of the first color filter pattern
67
. For this reason, unsatisfactory color reproducibility takes place, thus degrading the color picture characteristic to much degree.
Moreover, in a state as described above, as shown in
FIG. 5B
, there are instances where the third color filter pattern
69
takes a form riding onto the first color filter pattern
67
as indicated by color filter pattern
69
′ although it is not admitted into the adjacent pixel region. As a result, thick portions locally take place. Thus, any shift would similarly takes place in the spectral characteristic of the first color filter pattern
67
.
Further, with miniaturization of the device, the width of the light shielding film
65
between pixels becomes smaller. As a result, with the prior art, the problem that process margin cannot be taken place.
SUMMARY OF THE INVENTION
This invention has been made in view of the problems with the prior art, and its object is to provide a solid-state imaging device of the structure comprising color filter, and a color filter formation process suitable when applied thereto, in which the pattern end portion position of the color filter pattern is determined by the self-alignment with respect to the light shielding film so that the process margin with respect to the color reproducibility is increased.
A solid-state imaging device of this invention comprises: a semiconductor substrate, light shielding films formed so as to define light opening portions by a material of light shielding characteristic above the semiconductor substrate; and color filter layers formed above the light shielding films, and such that they are caused to correspond to the light opening portions and respective end portions thereof are positioned within regions corresponding to regions where the light shielding films are respectively formed.
Transfer electrodes are preferably respectively provided below the light shielding films in a more practical sense.
One of the color filter layers is preferably formed on a certain region where the light shielding film is formed in the state where a gap is held between the end portion thereof and that of the other color filter layer adjacent thereto.
Moreover, a method of manufacturing a solid-state imaging device of this invention comprises the steps of: forming a first insulating film on a semiconductor substrate; allowing a material of light shielding characteristic to selectively remain within regions where light shielding films are to be respectively formed on the fist insulating film to form the light shielding films; forming a second insulating film in this state; selectively forming a color filter layer on the second insulating film so as to cover an opening portion surrounded by the light shielding films and to allow respective end portions thereof to he positioned on the regions where the light shielding films are respectively formed.
Formation of the color filter layer is repeatedly carried out with respect to plural colors.
It is desirable to set light irradiation quantity so that the remaining film ratio (percentage) of the portion positioned on the light shielding film of resist constituting the color filter layer is lower than the remaining film ratio (percentage) of the portion positioned on the light opening portion.
REFERENCES:
patent: 5266501 (1993-11-01), Imai
patent: 5286605 (1994-02-01), Nishioka et al.
patent: 5466612 (1995-11-01), Fuse et al.
patent: 5514888 (1996-05-01), Sano et al.
patent: 5631753 (1997-05-01), Hamaguchi et al.
patent: 5708264 (1998-01-01), Hawkins et al.
patent: 5877040 (1999-03-01), Park et al.
patent: 5889277 (1999-03-01), Hawkins et al.
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kabushiki Kaisha Toshiba
LandOfFree
Solid-state imaging device and method of manufacturing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solid-state imaging device and method of manufacturing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solid-state imaging device and method of manufacturing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2974058