Selective SiN lateral recess
First Claim
1. An etching method comprising:
- flowing a fluorine-containing precursor and an oxygen-containing precursor into a processing region of the semiconductor processing chamber, wherein a substrate is positioned within the processing region, and wherein the substrate comprises a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide; and
laterally etching the layers of silicon nitride from sidewalls of the trench while substantially maintaining the layers of silicon oxide, wherein the layers of silicon nitride are laterally etched less than 10 nm from the sidewalls of the trench, and wherein a temperature within the processing region is maintained below about −
20°
C.
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Accused Products
Abstract
Exemplary methods for laterally etching silicon nitride may include flowing a fluorine-containing precursor and an oxygen-containing precursor into a remote plasma region of a semiconductor processing chamber. The methods may include forming a plasma within the remote plasma region to generate plasma effluents of the fluorine-containing precursor and the oxygen-containing precursor. The methods may also include flowing the plasma effluents into a processing region of the semiconductor processing chamber. A substrate may be positioned within the processing region, and the substrate may include a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide. The methods may also include laterally etching the layers of silicon nitride from sidewalls of the trench while substantially maintaining the layers of silicon oxide. The layers of silicon nitride may be laterally etched less than 10 nm from the sidewalls of the trench.
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Citations
17 Claims
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1. An etching method comprising:
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flowing a fluorine-containing precursor and an oxygen-containing precursor into a processing region of the semiconductor processing chamber, wherein a substrate is positioned within the processing region, and wherein the substrate comprises a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide; and laterally etching the layers of silicon nitride from sidewalls of the trench while substantially maintaining the layers of silicon oxide, wherein the layers of silicon nitride are laterally etched less than 10 nm from the sidewalls of the trench, and wherein a temperature within the processing region is maintained below about −
20°
C. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An etching method comprising:
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flowing a fluorine-containing precursor and an oxygen-containing precursor into a remote plasma region of a semiconductor processing chamber; forming a plasma within the remote plasma region to generate primary plasma effluents of the fluorine-containing and oxygen-containing precursors; flowing the primary plasma effluents into a processing region of the semiconductor processing chamber, wherein a substrate is positioned within the processing region, and wherein the substrate comprises a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide; oxidizing a portion of the silicon nitride from sidewalls of the trench to produce a fluorinated oxide region in each layer of silicon nitride; flowing a fluorine-containing precursor into the remote plasma region of the semiconductor processing chamber while generating a plasma to produce secondary plasma effluents; flowing the secondary plasma effluents into the processing region of the semiconductor processing chamber; and laterally etching the fluorinated oxide region from each layer of silicon nitride, wherein a temperature within the semiconductor processing chamber during the etching method is less than or about −
20°
C. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification