Method of low-selective etching of dissimilar materials having interfaces at non-perpendicular angles to the etch propagation direction
First Claim
1. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
- subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, a second gas which dominates an etching of said second material, and a third gas which reduces the etching rate of said first material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate.
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Abstract
A method of etching dissimilar materials having interfaces at non-perpendicular angles to the direction of the etch propagation that results in a low selectivity etch in order to achieve an improved planarized etched surface. The method includes the step of subjecting the dissimilar materials to a process gas mixture that includes a first gas that dominates the etching of a first material and a second gas that dominates the etching of a second material. The flow rates for the first and second materials are selected, along with other parameters of the plasma etch apparatus, to substantially equalize the etching rates for the two materials. This method is particularly useful to achieve a low-selective etching of materials having interfaces that are at a non-perpendicular angle with respect to the etch propagation.
19 Citations
14 Claims
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1. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, a second gas which dominates an etching of said second material, and a third gas which reduces the etching rate of said first material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, and a second gas which dominates an etching of said second material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate, wherein said first material comprises a mono- or poly-crystalline silicon and said first gas comprises chlorine (CL2).
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12. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, and a second gas which dominates an etching of said second material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate, wherein said first material comprises a mono- or poly-crystalline silicon and said third gas comprises di-fluoro methane (CH2F2).
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13. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, and a second gas which dominates an etching of said second material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate, wherein said second material comprises an oxide or a nitride and said second gas comprises CF4.
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14. In a plasma etching apparatus, a method of etching first and second materials having interfaces at non-perpendicular angles to the direction of an etch propagation, comprising:
subjecting said first and second materials to a plasma gas mixture comprising a first gas which dominates an etching of said first material, and a second gas which dominates an etching of said second material, wherein said plasma gas mixture etches said first and second materials at substantially the same rate, wherein said first material comprises mono- or poly-crystalline silicon and said first gas comprises hydrogen bromide (HBr) or chlorine (CL2);
wherein said second material comprises an oxide or a nitride and said second gas comprises CF4, and further including selecting secondary parameters of said plasma etching apparatus so that said first and second materials are etched at substantially the same rate.
Specification