Transistor manufacture
First Claim
1. A method of forming an oxide layer on material defining and surrounding an emitter window, comprising:
- depositing a non-conformal oxide layer on said material defining and surrounding said emitter window and in said emitter window, whereby the thickness of at least a portion of the oxide layer in the emitter window is smaller than the thickness of the oxide layer on said material defining and surrounding said emitter window; and
removing at least a portion of said oxide layer in said emitter window so as to reveal at least a portion of the bottom of said emitter window whilst permitting at least a portion of said oxide layer to remain on said material defining and surrounding said emitter window.
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Accused Products
Abstract
A method in which an oxide layer is formed on material defining and surrounding an emitter window. The technique comprises depositing a non-conformal oxide layer on the surrounding material and in the emitter window, whereby the thickness of at least a portion of the oxide layer in the emitter window is smaller than the thickness of the oxide layer on the surrounding material outside the emitter window; and removing at least a portion of the oxide layer in the emitter window so as to reveal at least a portion of the bottom of the emitter window whilst permitting at least a portion of the oxide layer to remain on the surrounding material. The technique can be used in the manufacture of a self-aligned epitaxial base BJT (bipolar junction transistor) or SiGe HBT (hetero junction bipolar transistor).
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Citations
17 Claims
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1. A method of forming an oxide layer on material defining and surrounding an emitter window, comprising:
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depositing a non-conformal oxide layer on said material defining and surrounding said emitter window and in said emitter window, whereby the thickness of at least a portion of the oxide layer in the emitter window is smaller than the thickness of the oxide layer on said material defining and surrounding said emitter window; and removing at least a portion of said oxide layer in said emitter window so as to reveal at least a portion of the bottom of said emitter window whilst permitting at least a portion of said oxide layer to remain on said material defining and surrounding said emitter window. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17)
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15. A semiconductor processing apparatus for forming an oxide layer on material defining and surrounding an emitter window, comprising:
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a depositor configured to deposit a non-conformal oxide layer on said material defining and surrounding said emitter window and in said emitter window, whereby the thickness of at least a portion of the oxide layer in the emitter window is smaller than the thickness of the oxide layer on said material defining and surrounding said emitter window; and a remover configured to remove at least a portion of said oxide layer in said emitter window so as to reveal at least a portion of the bottom of said emitter window whilst permitting at least a portion of said oxide layer to remain on said material defining and surrounding said emitter window.
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Specification