Semiconductor device in which an anti-reflective layer is formed by varying the composition thereof

• US 5,831,321 A
• Filed: 09/11/1996
• Issued: 11/03/1998
• Est. Priority Date: 04/05/1994
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nagayama, Tetsuji
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US08/712,256
• Time in Patent Office: 783 Days
• Field of Search: 257/412, 257/413, 257/437, 257/456, 257/639, 257/640, 257/646, 257/649
• US Class Current: 257/412
• 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 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: Y10S 430/151 Matting or other surface reflectivity altering material
• CPC Class Codes: Y10S 438/952 Utilizing antireflective layer

Abstract

A semiconductor device in which dry etching properties are rendered compatible with satisfactory anti-reflection characteristics in far-infrared lithography the semiconductor device has a semiconductor substrate and an electrode and wire pattern on the substrate. The semiconductor device also has an anti-reflective layer on the substrate which presents a variation in the composition of a constituent element along the film thickness over the semiconductor substrate. The anti-reflective layer is selected from the group consisting of SiO_x, SiN_x and Si_x O_y N_z.

Claims

1. A semiconductor device comprising:

a semiconductor substrate; and

an anti-reflective layer on said substrate said anti-reflective layer being a single layer of a material having a composition with one of its constituent elements varied in quantity along the thickness of the layer over the semiconductor substrate, the anti-reflective layer being selected from the group consisting of SiO_x, SiN_x and Si_x O_y N_z.

2. The semiconductor device as claimed in claim 1, wherein the anti-reflective layer has a composition selected such that an upper layer portion thereof has a refractive index higher than that of a lower layer portion.

3. The semiconductor device as claimed in claim 2, wherein the anti-reflective layer is a film formed of a silicon compound and having a composition with a variable silicon ratio.

4. The semiconductor device as claimed in claim 2, wherein the anti-reflective layer has a silicon-rich upper layer portion.

5. The semiconductor device as claimed in claim 2, wherein the anti-reflective layer is a film formed of a silicon compound and having a silicon ratio in the composition thereof increased from its lower layer portion towards its upper layer portion.

6. The semiconductor device as claimed in claim 2, further comprising a photoresist film formed over the anti-reflective layer, wherein the anti-reflective layer is film having a lower refractive index area and a high refractive index area formed on the low refractive index area, said higher refractive index area having a refractive index higher than that of the photoresist film.

7. The semiconductor device as claimed in claim 1, wherein the anti-reflective layer is a film formed of a silicon compound having a variable silicon ratio.

8. The semiconductor device as claimed in claim 1, wherein the anti-reflective layer has a silicon-rich upper layer portion.

9. The semiconductor device as claimed in claim 1, wherein the anti-reflective layer is film formed of a silicon compound having a silicon ratio which increases proceeding from a lower layer portion thereof toward an upper layer portion thereof.