Ultra-thin resist and oxide/nitride hard mask for metal etch
First Claim
1. A method of forming a metal line, comprising:
- providing a semiconductor substrate comprising a metal layer, a silicon nitride layer over the metal layer, and an oxide layer over the silicon nitride layer;
depositing an ultra-thin photoresist over the oxide layer, the ultra-thin photoresist having a thickness less than about 2,000 Å
;
irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 250 nm or less;
developing the ultra-thin photoresist exposing a portion of the oxide layer;
etching the exposed portion of the an oxide layer exposing a portion of the silicon nitride layer with a first etch chemistry being oxide;
photoresist selective;
etching the exposed portion of the silicon nitride layer exposing a portion of the metal layer with a second etch chemistry being both silicon nitride;
oxide selective and silicon nitride;
metal selective; and
etching the exposed portion of the metal layer with a third etch chemistry being metal;
silicon nitride selective thereby forming the metal line.
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Accused Products
Abstract
In one embodiment, the present invention relates to a method of forming a metal line, involving the steps of providing a semiconductor substrate comprising a metal layer, a silicon nitride layer over the metal layer, and an oxide layer over the silicon nitride layer; depositing an ultra-thin photoresist over the oxide layer, the ultra-thin photoresist having a thickness less than about 2,000 Å; irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 250 nm or less; developing the ultra-thin photoresist exposing a portion of the oxide layer; etching the exposed portion of the oxide layer exposing a portion of the silicon nitride layer; etching the exposed portion of the silicon nitride layer exposing a portion of the metal layer; and etching the exposed portion of the metal layer thereby forming the metal line.
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Citations
26 Claims
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1. A method of forming a metal line, comprising:
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providing a semiconductor substrate comprising a metal layer, a silicon nitride layer over the metal layer, and an oxide layer over the silicon nitride layer;
depositing an ultra-thin photoresist over the oxide layer, the ultra-thin photoresist having a thickness less than about 2,000 Å
;
irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 250 nm or less;
developing the ultra-thin photoresist exposing a portion of the oxide layer;
etching the exposed portion of the an oxide layer exposing a portion of the silicon nitride layer with a first etch chemistry being oxide;
photoresist selective;
etching the exposed portion of the silicon nitride layer exposing a portion of the metal layer with a second etch chemistry being both silicon nitride;
oxide selective and silicon nitride;
metal selective; and
etching the exposed portion of the metal layer with a third etch chemistry being metal;
silicon nitride selective thereby forming the metal line.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of etching metal to form metal lines, comprising:
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providing a semiconductor substrate comprising a metal layer, a silicon nitride layer over the metal layer, and an oxide layer over the silicon nitride layer;
depositing an ultra-thin photoresist over the oxide layer, the ultra-thin photoresist having a thickness from about 500 Å
to about 2,000 Å
;
irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 200 nm or less;
developing the ultra-thin photoresist exposing a portion of the oxide layer, wherein the exposed portion of the oxide layer has a width of about 0.1 μ
m or less;
etching the exposed portion of the oxide layer exposing a portion of the silicon nitride layer with a first etch chemistry being oxide;
photoresist selective;
etching the exposed portion of the silicon nitride layer exposing a portion of the metal layer with a second etch chemistry being both silicon nitride;
oxide selective and silicon nitride;
metal selective; and
etching the exposed portion of the metal layer with a third etch chemistry being metal;
silicon nitride selective thereby forming metal lines.- View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of processing a semiconductor substrate, comprising:
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providing a semiconductor substrate comprising a metal layer, a silicon nitride layer over the metal layer, and an oxide layer over the silicon nitride layer, wherein the metal layer comprises aluminum;
depositing an ultra-thin photoresist over the oxide layer, the ultra-thin photoresist having a thickness from about 500 Å
to about 2,000 Å
;
irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 200 nm or less;
developing the ultra-thin photoresist exposing a portion of the oxide layer;
etching the exposed portion of the oxide layer exposing a portion of the silicon nitride layer with a first etch chemistry being oxide;
photoresist selective;
etching the exposed portion of the silicon nitride layer exposing a portion of the metal layer with a second etch chemistry being both silicon nitride;
oxide selective and silicon nitride;
metal selective; and
etching the exposed portion of the metal layer with a third etch chemistry being metal;
silicon nitride selective thereby forming the metal line having a width of about 0.1 μ
m or less.- View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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Specification