Stabilized multi-layered structure of color filters on a silicon chip and a method for making

• US 5,871,871 A
• Filed: 09/20/1996
• Issued: 02/16/1999
• Est. Priority Date: 09/20/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hogan, Dennis Pfleegor, Leidy, Robert Kenneth, Linde, Harold George
• Primary Examiner(s): McPherson, John A.
• Application Number:
  US08/717,340
• Time in Patent Office: 879 Days
• Field of Search: 430/7, 430/321, 349/106, 257/440, 348/273
• US Class Current: 430/7
• CPC Class Codes: G02B 5/23 Photochromic filters

Abstract

There is provided, a stabilized multi-layered colored filter structure useful in a digital color camera and method for making same. The method involves effecting reaction between a polyfunctional organosilicon material, such as a hexaorganosilazane with at least one phenolic resist containing an organic dye color forming filter, in a multi-layered structure of color filters on a silicon chip.

Claims

1. A photo chromatic filtering system comprising:

an electroactive substrate; and

a multi-layered structure of contiguous light filters respectively positioned on at least a portion of the electroactive substrate, wherein each light filter includes a phenolic resin and can respectively filter light having a first predetermined wavelength, a second predetermined wavelength, and a third predetermined wavelength, and wherein at least one of the contiguous light filters has been patterned, reacted with a polyfunctional organosilicon material, and hard baked such that the reacted light filter is of itself a transparent cross-linked stabilizing layer.

2. A photo chromatic filtering system in accordance with claim 1, wherein the polyfunctional organosilicon material is a hexaorganocyclosilazane.

3. A digital color camera using the photochromatic filtering system of claim 1 as an image sensor.

4. A photo chromatic filtering system comprising:

an electroactive substrate;

a first stable transparent resin permanently formed on a portion of said substrate to filter light having a first predetermined wavelength;

a second stable transparent resin permanently formed on a portion of said substrate and a portion of said first stable transparent resin to filter light having a second predetermined wavelength; and

a third stable transparent resin permanently formed on a portion of said substrate and a portion of said first stable transparent resin and a portion of said second transparent resin to filter light having a third predetermined wavelength, wherein at least one of the transparent resins was patterned, reacted with a polyfunctional organosilicon material, and hard baked such that the reacted resin is of itself a cross-linked stabilizing layer to render each transparent resin a stable transparent resin.

5. A digital color camera having a charge-coupled device and a color filter exhibiting improved stability, which color filter comprises an electroactive silicon chip having solvent coated multi-contiguous color resist layers, wherein at least one of the solvent coated color resist layers had been patterned, reacted with a polyfunctional organosilicon material, and hard baked such that the reacted color resist layer is of itself a transparent stabilizing layer.

6. A method for making a stabilized multi-layered structure of color filters on a silicon substrate comprising the steps of:

(1) (a) initially exposing a surface of the silicon substrate with an organodisilazane to render it hydrophobic,

(b) applying a phenolic resist having a first color filter onto the surface of the silicon substrate and thereafter patterning and baking the applied phenolic resist;

(2) (c) exposing the surface of the treated silicon substrate with an organodisilazane to render it hydrophobic;

(d) applying a resist having a second color filter onto the treated silicon substrate, exposing the applied resist to pattern it, and thereafter developing the patterned resist,

(e) treating the surface of the patterned resist with a hexaorganocyclotrisilazane, and

(f) thereafter rinsing the treated silicon substrate with an organic resist solvent followed by baking,

(3) (g) applying a resist having a third color filter onto the resulting treated silicon substrate,

(h) and thereafter, exposing, developing and baking the applied resist.

7. A method of making a stabilized multi-layered structure of colored filters on a silicon substrate in accordance with claim 6, wherein the first color filter is a red color filter.

8. A method for making a stabilized multi-layered structure of colored filters on a silicon substrate in accordance with claim 6, wherein the second color filter is a blue color filter.

9. A method for making a stabilized multi-layered structure for colored filters on a silicon substrate in accordance with claim 6, wherein the third color filter is a green color filter.

10. A method in accordance with claim 6, wherein the phenolic resist is a novolac.

11. A method in accordance with claim 6, wherein the organodisilazane is hexamethyldisilazane.

12. A method in accordance with claim 6, wherein the hexaorganocyclotrisilazane is hexamethylcyclotrisilazane.

13. A method in accordance with claim 6, wherein propylene glycol monomethyl ether acetate is used as the resist solvent.

14. A method in accordance with claim 6, wherein only the second color filter is of itself a cross-linked stabilizing layer.

15. A method in accordance with claim 6, wherein the multi-layered structure of color filters on a silicon substrate is useful in a color digital camera as an image sensor when rendered electroactive, the method is practiced in an environmentally safe manner as a result of the substantial exclusion during processing of environmentally unsafe organic solvents, and the color filters result from the application and processing of phenolic resists each containing an organic dye respectively corresponding to a color filter.

16. A method in accordance with claim 6, wherein the baking occurs at a temperature of approximately 145°

C. for approximately 2 to 5 hours.

17. A method in accordance with claim 6, wherein only the second color filter and one of either the first or third color filter are of themselves a cross-linked stabilizing layer.