Antireflective coating layer

• US 6,614,085 B2
• Filed: 10/31/2001
• Issued: 09/02/2003
• Est. Priority Date: 08/21/1997
• Status: Expired due to Term

• Current Assignee: Nanya Technology Corporation
• Original Assignee: Micron Technology, Inc.
• Inventors: Hu, Yongjun
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): LOUIE, WAI SING
• Application Number:
  US10/003,522
• Publication Number:
  US 20020105043A1
• Time in Patent Office: 671 Days
• Field of Search: 257/437, 438/48, 438/72, 438/636
• US Class Current: 257/437
• CPC Class Codes: G03F 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/318 composed of nitrides
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 31/02161 for devices characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: Y10S 430/151 Matting or other surface reflectivity altering material

Abstract

Antireflective structures according to the present invention comprise a metal silicon nitride composition in a layer that is superposed upon a layer to be patterned that would other wise cause destructive reflectivity during photoresist patterning. The antireflective structure has the ability to absorb light used during photoresist patterning. The antireflective structure also has the ability to scatter unabsorbed light into patterns and intensities that are ineffective to photoresist material exposed to the patterns and intensities. Preferred antireflective structures of the present invention comprise a semiconductor substrate having thereon at least one layer of a silicon-containing metal or silicon-containing metal nitride. The semiconductor substrate will preferably have thereon a feature size with width dimension less than about 0.5 microns, and more preferably less than about 0.25 microns. One preferred material for the inventive antireflective layer includes metal silicon nitride ternary compounds of the general formula M_xSi_yN_z wherein M is at least one transition metal, x is less than y, and z is in a range from about 0 to about 5y. Preferably, the Si will exceed M by about a factor of two. Addition of N is controlled by the ratio in the sputtering gas such as Ar/N. Tungsten is a preferred transition metal in the fabrication of the inventive antireflective coating. A preferred tungsten silicide target will have a composition of silicon between 1 and 4 in stoichiometric ratio to tungsten. Composite antireflective layers made of metal silicide binary compounds or metal silicon nitride ternary compounds may be fashioned according to the present invention depending upon a specific application.

Claims

1. An antireflective coating comprising:

a material substantially composed of M_xSi_yN_z, wherein;

M includes at least two transition metals of the configuration M1_rM2_1-r,

wherein r is in a range from 0 to 1;

y is greater than x; and

z is in a range from about 0 to about 5y.

2. The antireflective coating of claim 1, wherein M1 is tungsten and r is 1.

3. The antireflective coating of claim 1, wherein M1 is tungsten, M2 is titanium, and r is about 0.5.

4. The antireflective coating of claim 1, wherein said antireflective coating has a thickness range from about 25 Angstroms to about 1,000 Angstroms.

5. The antireflective coating of claim 1, wherein said antireflective coating has a thickness range from about 50 Angstroms to about 400 Angstroms.

6. The antireflective coating of claim 1, wherein said antireflective coating has a thickness range from about 85 Angstroms to about 200 Angstroms.

7. The antireflective coating of claim 1, wherein y equals about 2x.

8. The antireflective coating of claim 1, wherein y equals about 2.55x.

9. The antireflective coating of claim 1, wherein y equals about 2.7x.

10. The antireflective coating of claim 1, wherein M1 and M2 are selected from the group consisting of Sc, Ti, Zr, Nb, Ta, Mo, W, Co, and Ni, and wherein M1 is not M2.

11. The antireflective coating of claim 1, wherein z is in a range from about 1y to about 2y.

12. The antireflective coating of claim 1, further comprising hemispherical grained polysilicon.

13. An antireflective coating comprising:

a metal silicon nitride ternary compound comprising at least one metal selected from the group consisting of Sc, Co, Al, and Ni;

wherein the antireflective coating is configured to minimize reflectivity of deep ultraviolet light.

15. The antireflective coating of claim 13, further comprising hemispherical grained polysilicon.

14. An antireflective coating comprising a metal silicon nitride compound selected from the group consisting of titanium tungsten silicon nitride, tungsten aluminum silicon nitride, and titanium aluminum silicon nitride.

16. An antireflective coating comprising:

a metal silicide binary compound comprising at least one metal selected from the group consisting of Sc, Ti, Zr, Nb, Ta, Mo, W, Co, Al, and Ni;

wherein the antireflective coating is configured to minimize reflectivity of deep ultraviolet light.

17. An antireflective coating comprising:

a metal silicide binary compound comprising at least one metal selected from the group consisting of Sc, Ti, Zr, Nb, Ta, Mo, W, Co, Al, and Ni;

the metal silicide binary compound is M1_rM2_1-rSi_s;

M1 and M2 are both metal and are selected from said group;

M1 is not M2;

r is in a range from 0 to 1; and

s is greater than zero.