DEVICE HAVING THIN BLACK MASK AND METHOD OF FABRICATING THE SAME

• US 20090257105A1
• Filed: 04/10/2008
• Published: 10/15/2009
• Est. Priority Date: 04/10/2008
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Xu, Gang, Wang, Chun-Ming, Zhong, Fan, Luo, Qi
• Granted Patent: US 7,969,638 B2
• Time in Patent Office: Days
• US Class Current: 359/242
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 5/003 Light absorbing elements
• CPC Class Codes: G02B 5/201 in the form of arrays

Abstract

A thin black mask is created using a single mask process. A dielectric layer is deposited over a substrate. An absorber layer is deposited over the dielectric layer and a reflector layer is deposited over the absorber layer. The absorber layer and the reflector layer are patterned using a single mask process.

Claims

1. A method of making a black mask, the method comprising:

depositing a dielectric layer on a substrate;

depositing an absorber layer on the dielectric layer;

depositing a reflector layer on the absorber layer; and

patterning the absorber layer and the reflector layer in a single mask process.

2. The method of claim 1, wherein a step size resulting from patterning the absorber layer and reflector layer in the single mask process is less then 600 angstroms in height.

3. The method of claim 1, wherein patterning the absorber layer and the reflector layer comprises etching the absorber layer and the reflector layer but not the dielectric layer.

4. The method of claim 1, wherein the dielectric layer has an extinction coefficient in a range from 0 to 0.1 and a refractive index in a range of 1 to 3.

5. The method of claim 1, wherein the absorber layer has an extinction coefficient in a range from 1 to 4 and a refractive index in a range of 1 to 5.

6. The method of claim 1, wherein the reflector layer has an extinction coefficient in a range from 1 to 5 and a refractive index in a range of 0.1 to 5.

7. The method of claim 1, wherein the reflector layer comprises metallic material.

8. A device comprising:

a black mask wherein a step size resulting from a patterning of the black mask is less than 600 angstroms, and

the reflectance of the black mask is less than one percent of incoming light.

9. The device of claim 8, wherein the black mask comprises a stack of interference films.

10. A device comprising:

a black mask comprising a first, second, and a third layer in succession;

the first layer with a first k/n ratio over a wavelength range;

the second layer with a second k/n ratio over the wavelength range;

the third layer with a third k/n ratio over the wavelength range;

wherein the first k/n ratio is less than the second k/n ratio and the second k/n ratio is less than the third k/n ratio.

11. The device of claim 10, wherein the black mask comprises a stack of interference films.

12. The electronic device of claim 10, wherein the stacked layers comprise:

a dielectric layer deposited over the substrate,

an absorber layer deposited over the dielectric layer, and

a reflector layer deposited over the absorber layer.

13. The device of claim 12, wherein the dielectric layer has an extinction coefficient in a range from 0 to 0.1 and a refractive index in a range of 1 to 3.

14. The device of claim 12, wherein the absorber layer has an extinction coefficient in a range from 1 to 4 and a refractive index in a range of 1 to 5.

15. The device of claim 12, wherein the reflector layer has an extinction coefficient in a range from 1 to 5 and a refractive index in a range of 0.1 to 5.

16. The device of claim 12, wherein the dielectric layer comprises at least two layers of material.

17. The device of claim 12, wherein the absorber layer comprises at least two layers of material.

18. The device of claim 12, wherein the reflector layer comprises at least two layers of material.

19. A device comprising a black mask having a dielectric layer, an absorber layer, and a reflector layer wherein:

the dielectric layer comprises at least one of;

SiO2, SiNx, MgF2, ITO, Al2O3, Yi2O3, and ZnO,

the absorber layer comprises at least one of;

a-Si, a-Ge, silicon alloys, and germanium alloys, and

the reflector layer comprises at least one of;

Mo, Cr, Ni, Al, and Ag.

20. A device, comprising:

a substrate; and

a black mask deposited over the substrate, the black masking comprising

a dielectric layer deposited over a substrate,

an absorber layer deposited over the dielectric layer, and

a reflector layer deposited over the absorber layer.

21. The device of claim 20, wherein the absorber layer and the reflector layer are patterned to correspond with display elements formed above the black mask with respect to the substrate.

22. The device of claim 20, wherein a step size resulting from patterning the absorber layer and the reflector layer is less then 600 angstroms.

23. The device of claim 20, wherein a step size resulting from patterning the absorber layer and the reflector layer in a single mask step is less then 600 angstroms.

24. A device, comprising:

a substrate; and

means for absorbing light comprising;

means for insulating deposited over the substrate;

means for absorbing light deposited over the insulating means; and

means for reflecting deposited over the light absorbing means.

25. The device of claim 24, wherein the insulating means comprises at least one of SiO2, SiNx, MgF2, ITO, Al2O3, Yi2O3, and ZnO, the light absorbing means comprises at least one of a-Si, a-Ge, silicon alloys, and germanium alloys, and the reflecting means comprises at least one of Mo, Cr, Ni, Al, and Ag.

26. The device of claim 24, wherein the light absorbing means and the reflecting means are patterned to correspond with display elements formed above the light absorbing means with respect to the supporting means.