Multilevel interconnection structure having an air gap between interconnects

Claim 2

A semiconductor device comprising a semiconductor substrate, a first dielectric film overlying said semiconductor substrate, first metal interconnects having a top portion and a bottom portion, wherein said top portion is disposed on a top surface of said first dielectric film and said bottom portion extends through said first dielectric film to contact said semiconductor substrate, a first air gap occupying substantially all of a space between said first dielectric film and a second dielectric film formed on said top portion of said first metal interconnects, except in a space occupied by said first metal interconnects, second metal interconnects having a top portion and a bottom portion, wherein said top portion is disposed on a top surface of said second dielectric film and said bottom portion of said second metal interconnects extends through said second dielectric film to contact said top portion of said first metal interconnects, said first air gap communicating with a second air gap, said second air gap occupying substantially all of a space between said second dielectric film and a third dielectric film formed on said top portion of said second metal interconnects, except in a space occupied by said second metal interconnects, between said second dielectric film and a third dielectric film formed on said top portion of said second metal interconnects, said semiconductor device further comprising a side-wall film covering side surfaces of each of said top portion of at least one of said first metal interconnects and said second metal interconnects.

Claim 3

A semiconductor device as defined in claim 1, further comprising at least a fourth dielectric film layer formed on a top portion of third metal interconnects, said third metal interconnects having said top portion and a bottom portion, wherein said top portion is disposed on a top surface of said third dielectric film and said bottom portion extends through said third dielectric film to contact said top portion of said second metal elements, and a third air gap occupying substantially all of a space, except in the locations of said third metal interconnects, between said third dielectric film and said fourth dielectric film.

Claim 4

A semiconductor device as defined in claim 1, wherein each of said dielectric films comprises a SiOF compound.

Claim 5

A semiconductor device as defined in claim 1, wherein each of said dielectric films comprises silicon dioxide.

Claim 6

A semiconductor device comprising: a semiconductor substrate; a first dielectric film overlying said semiconductor substrate, said first dielectric film having an upper surface and a lower surface, wherein said lower surface of said first dielectric film contacts said semiconductor substrate; a plurality of openings in said first dielectric film; a first plurality of conductive elements occupying said plurality of openings in said first dielectric film, said first plurality of conductive elements contacting said semiconductor substrate and extending through said upper surface of said first dielectric film, at least some of said first plurality of conductive elements having a portion that extends above said upper surface of said first dielectric film; a second dielectric film, said second dielectric film having an upper surface and a lower surface, wherein said lower surface of said second dielectric film contacts said portion that extends above said upper surface of said first dielectric film; a first space occupying substantially all of a space between said portion that extends above said upper surface of said first dielectric film, said upper surface of said first dielectric film, and said lower surface of said second dielectric film; a plurality of openings in said second dielectric film; a second plurality of conductive elements occupying said plurality of openings in said second dielectric film, said second plurality of conductive elements contacting at least some of said first plurality of conductive elements and extending through said upper surface of said second dielectric film, at least some of said second plurality of conductive elements having a portion that extends above said upper surface of said second dielectric film; a third dielectric film, said third dielectric film having an upper surface and a lower surface, wherein said lower surface of said third dielectric film contacts said portion that extends above said upper surface of said second dielectric film; and a second space occupying substantially all of a space between said portion that extends above said upper surface of said second dielectric film, said upper surface of said second dielectric film, and said lower surface of said third dielectric film, wherein said first space is in communication with said second space, said semiconductor device further comprises a side-wall film covering a side surface of one of said first conductive elements and said second conductive elements.

Claim 7

A semiconductor device comprising: a semiconductor substrate; a first dielectric film overlying said semiconductor substrate, said first dielectric film having an upper surface and a lower surface, wherein said lower surface of said first dielectric film contacts said semiconductor substrate; a plurality of openings in said first dielectric film; a first plurality of conductive elements occupying said plurality of openings in said first dielectric film, said first plurality of conductive elements contacting said semiconductor substrate and extending through said upper surface of said first dielectric film, at least some of said first plurality of conductive elements having a portion that extends above said upper surface of said first dielectric film; a second dielectric film, said second dielectric film having an upper surface and a lower surface, wherein said lower surface of said second dielectric film contacts said portion that extends above said upper surface of said first dielectric film; a first space occupying substantially all of a space between said portion that extends above said upper surface of said first dielectric film, said upper surface of said first dielectric film, and said lower surface of said second dielectric film; a plurality of openings in said second dielectric film; a second plurality of conductive elements occupying said plurality of openings in said second dielectric film, said second plurality of conductive elements contacting at least some of said first plurality of conductive elements and extending through said upper surface of said second dielectric film, at least some of said second plurality of conductive elements having a portion that extends above said upper surface of said second dielectric film; a third dielectric film, said third dielectric film having an upper surface and a lower surface, wherein said lower surface of said third dielectric film contacts said portion that extends above said upper surface of said second dielectric film; and a second space occupying substantially all of a space between said portion that extends above said upper surface of said second dielectric film, said upper surface of said second dielectric film, and said lower surface of said third dielectric film, wherein said first space is in communication with said second space, said semiconductor device further comprises a side-wall film covering a side surface of one of said first conductive elements and said second conductive elements.

Claim 8

A semiconductor device as defined in claim 5, further comprising: a plurality of openings in said third dielectric film; a third plurality of conductive elements occupying said plurality of openings in said third dielectric film, said third plurality of conductive elements contacting at least some of said second plurality of conductive elements and extending through said upper surface of said third dielectric film, at least some of said third plurality of conductive elements having a portion that extends above said upper surface of said third dielectric film; a fourth dielectric film, said fourth dielectric film having an upper surface and a lower surface, wherein said lower surface of said fourth dielectric film contacts said portion that extends above said upper surface of said third dielectric film; and a third space occupying substantially all of a space between said third plurality of conductive elements, said upper surface of said third dielectric film, and said lower surface of said fourth dielectric film.

Claim 9

A semiconductor device as defined claim 6, wherein said third space is occupied by air.

Claim 10

A semiconductor device as defined claim 6, wherein said fourth dielectric film is covered by a protective layer.

Claim 11

A semiconductor device as defined claim 8, wherein said protective layer is a SiN film.

Claim 12

A semiconductor device as defined in claim 6, wherein each of said dielectric films comprises a SiOF compound.

Claim 13

A semiconductor device as defined in claim 6, wherein each of said dielectric films comprises a silicon oxide compound.

Claim 14

A semiconductor device as defined claim 5, wherein said first space and said second space are occupied by air.

Claim 15

A semiconductor device as defined claim 5, wherein said third dielectric film is covered by a protective layer.

Claim 16

A semiconductor device as defined claim 13, wherein said protective layer is a SiN film.

Claim 17

A semiconductor device as defined in claim 5, wherein each of said dielectric films comprises a SiOF compound.

Claim 18

A semiconductor device as defined in claim 5 wherein each of said dielectric films comprises a silicon oxide compound.