Process for forming a semiconductor device

• US 6,043,146 A
• Filed: 07/27/1998
• Issued: 03/28/2000
• Est. Priority Date: 05/21/1997
• Status: Expired due to Term

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Watanabe, Joy Kimi, Stankus, John Joseph
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): MAI, ANH D
• Application Number:
  US09/122,709
• Time in Patent Office: 610 Days
• Field of Search: 438/238, 438/239, 438/396, 438/397, 438/597, 438/598, 438/618, 438/620, 438/622, 438/623, 438/624, 438/626, 438/628, 438/690, 438/691, 438/692, 438/631, 438/633, 438/634
• US Class Current: 438/623
• CPC Class Codes: H01L 21/76819 Smoothing of the dielectric planarisation of insulating materials per se H01L21/31051
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/53295 Stacked insulating layers
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A buffer film (154, 164) is formed over an underlying film (153, 162) to protect that underlying film (153, 162) from damage during a removal sequence, such as polishing. Scratches, gouging, smearing that can occur to the underlying layer (153, 162) are less likely to occur because of the presence of the buffer film (154, 164). In some embodiments, an insulating film (162) is to be protected. The buffer film (164) is formed over the insulating film (162), and the insulating and buffer films (162 and 164) are patterned. During a subsequent conductive layer polishing operation in an embodiment, most of the buffer film (164) is removed. In still another embodiment, a buffer film (154) is formed over a conductive layer (153) to protect it during "gap fill" process sequence. Although residual portions of the buffer film (154, 164) are usually removed, in some instances, those residual portions can remain if there are no significant adverse affects.

Claims

1. A process for forming a semiconductor device comprising:

forming an insulating film over a substrate and a conductive region;

forming a first buffer film over the insulating film;

patterning the first buffer film and the insulating film to form an opening, wherein a portion of the opening exposes a portion of the conductive region;

forming a first conductive layer over the first buffer film and within the opening, wherein the first conductive layer contacts the conductive region; and

removing a portion of the first conductive layer overlying the insulating film and most of the first buffer film that overlies the insulating film.

2. The process of claim 1, wherein:

most of the first buffer film is removed during removing the portion of the first conductive layer, wherein a remaining portion of the first buffer film is formed; and

the process further comprises removing the remaining portion of the first buffer film.

3. The process of claim 1, wherein the insulating film includes a porous material.

4. The process of claim 1, wherein the insulating film includes an organic material.

5. The process of claim 1, wherein removing the first buffer film comprises a method selected from a group consisting of decomposing the first buffer film, dissolving the first buffer film, evaporating the first buffer film, and exposing the first buffer film to an oxygen-containing plasma.

6. The process of claim 1, wherein the first buffer film comprises a material selected from a group consisting of benzo-cyclobutene, polyvinylacetate, polyvinylalcohol, polyethylene, polypropylene, and polymethylmethacrylate.

7. The process of claim 1, wherein the first buffer film has a thickness of at least approximately 100 nanometers.

8. The process of claim 1, further comprising forming a hard mask film over the first buffer film before patterning.

9. The process of claim 1, further comprising forming a passivation layer after removing the portion of the first conductive layer.

10. The process of claim 9, wherein the first conductive layer includes a barrier film, wherein the barrier film includes a refractory metal material.

11. The process of claim 9, further comprising forming a hard mask film over the first buffer film before patterning.

12. The process of claim 1, further comprising:

forming a second buffer film over the first conductive layer;

polishing the second buffer film before removing the first conductive layer; and

removing the second buffer film after removing the first conductive layer.

13. The process of claim 12, further comprising:

forming a dielectric film over the first conductive layer;

forming a second conductive layer over the dielectric film;

patterning the second conductive layer to form a capacitor; and

forming an interconnect film over the second conductive layer and the insulating film.

14. A process for forming a semiconductor device comprising:

forming a first film over a substrate;

forming a second film over the first film;

patterning the first and second films to form an opening, wherein the opening extends through all the second film and at least partially through the first film;

forming a third film over the second film and within the opening;

removing a portion of the third film that overlies the second film and most of the second film that overlies the first film.

15. The process of claim 14, wherein:

the first and third films are insulative films; and

a refractive index of the third film is higher than a refractive index of the first film.

16. The process of claim 14, further comprising:

forming a fourth film after patterning and before forming the third film;

forming a fifth film along exposed portions of the third film after removing the portion of the third film; and

forming a sixth film over the fifth film and the first film,

wherein the first, third, and sixth films are conductive films, and wherein the fourth and fifth films are insulative films.

17. The process of claim 16, further comprising removing all remaining portions of the second film before forming the sixth film.

18. The process of claim 14, further comprising forming a passivation layer of the substrate after removing the portion of the third film.