NF3/H2 REMOTE PLASMA PROCESS WITH HIGH ETCH SELECTIVITY OF PSG/BPSG OVER THERMAL OXIDE AND LOW DENSITY SURFACE DEFECTS
First Claim
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1. A method for treating a semiconductor substrate having doped regions and undoped regions, comprising:
- disposing the semiconductor substrate in a processing chamber;
providing a reactive gas mixture comprising hydrogen radicals and fluorine radicals to the processing chamber;
exposing the semiconductor substrate to the reactive gas mixture; and
etching the doped regions of the semiconductor substrate faster than the undoped regions in a carbon-free dry etch process.
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Abstract
A method and apparatus for selectively etching doped semiconductor oxides faster than undoped oxides. The method comprises applying dissociative energy to a mixture of nitrogen trifluoride and hydrogen gas remotely, flowing the activated gas toward a processing chamber to allow time for charged species to be extinguished, and applying the activated gas to the substrate. Reducing the ratio of hydrogen to nitrogen trifluoride increases etch selectivity. A similar process may be used to smooth surface defects in a silicon surface.
297 Citations
24 Claims
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1. A method for treating a semiconductor substrate having doped regions and undoped regions, comprising:
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disposing the semiconductor substrate in a processing chamber; providing a reactive gas mixture comprising hydrogen radicals and fluorine radicals to the processing chamber; exposing the semiconductor substrate to the reactive gas mixture; and etching the doped regions of the semiconductor substrate faster than the undoped regions in a carbon-free dry etch process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of processing a substrate, comprising:
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disposing the substrate in a processing chamber; depositing a doped silicate glass layer on the substrate; depositing an undoped silicate glass layer on the substrate; and etching the deposited layers using a carbon-free dry etch process having an etch selectivity of the doped silicate glass layer over the undoped silicate glass layer of at least 1.2. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of treating a semiconductor substrate, comprising:
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disposing the substrate in a substrate processing chamber; forming a reactive gas mixture comprising neutral hydrogen radicals and fluorine radicals in a remote activation chamber; flowing the reactive gas mixture toward a substrate processing chamber for a time interval sufficient to extinguish charged species; exposing a surface of the substrate to the reactive gas mixture; and smoothing defects in the surface of the substrate by reacting the reactive gas mixture with oxides and dopants in the surface of the substrate. - View Dependent Claims (24)
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Specification