Method for forming a semiconductor device
First Claim
1. A method for forming a semiconductor device, comprising:
- forming via-level dielectric film overlying a semiconductor device substrate;
forming a trench-level dielectric film directly on and in contact with the via-level dielectric film;
etching a via opening in the trench-level dielectric film with a first etch chemistry, wherein the first etch chemistry has a higher etch selectivity to the trench-level dielectric film than to the via-level dielectric film;
providing a photoresist layer overlying the trench-level dielectric film, the photoresist layer having a photoresist opening overlying the via opening in the trench-level dielectric film;
etching the via-level dielectric film with a second etch chemistry to extend the via opening into the via-level dielectric film; and
etching into the trench-level dielectric film through the photoresist opening to form a trench opening.
19 Assignments
0 Petitions
Accused Products
Abstract
In accordance with embodiments of the present invention a trench-level dielectric film (26) and a via-level dielectric film (24) are formed overlying a semiconductor device substrate (10). A via opening (42) is etched in the trench-level dielectric film with a first etch chemistry that has a higher etch selectivity to the trench-level dielectric film (26) than to the via-level dielectric film (24). A trench opening (54) is patterned in a photoresist layer (52) overlying the trench-level dielectric film (26). The via-level dielectric film (24) is etched with a second etch chemistry to extend the via opening (42) into the via-level dielectric film (24). The trench-level dielectric film (26) is etched to form a trench opening.
59 Citations
20 Claims
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1. A method for forming a semiconductor device, comprising:
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forming via-level dielectric film overlying a semiconductor device substrate; forming a trench-level dielectric film directly on and in contact with the via-level dielectric film; etching a via opening in the trench-level dielectric film with a first etch chemistry, wherein the first etch chemistry has a higher etch selectivity to the trench-level dielectric film than to the via-level dielectric film; providing a photoresist layer overlying the trench-level dielectric film, the photoresist layer having a photoresist opening overlying the via opening in the trench-level dielectric film; etching the via-level dielectric film with a second etch chemistry to extend the via opening into the via-level dielectric film; and etching into the trench-level dielectric film through the photoresist opening to form a trench opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for forming a semiconductor device, comprising the sequential steps of:
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forming via-level dielectric film overlying a semiconductor device substrate, said via-level dielectric film comprising an oxide of silicon; forming a trench-level dielectric film directly on and in contact with the via-level dielectric film, said trench-level dielectric film comprising a low k dielectric material, said low k dielectric material having a dielectric constant not greater than 3.5; etching a via opening in the trench-level dielectric film with a first etch chemistry, wherein the first etch chemistry has a higher selectivity to the trench-level dielectric film than to the via-level dielectric film; providing a photoresist layer overlying the trench-level dielectric film, the photoresist layer having a photoresist opening over the via opening in the trench-level dielectric film; etching the via-level dielectric film with a second etch chemistry to extend the via opening into the via-level dielectric film; and etching into the trench-level dielectric film through the photoresist opening to form a trench opening. - View Dependent Claims (20)
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Specification