Hydrogen iodide etch of tin oxide
AssigneeTexas Instruments Incorporated
InventorJaroslav Hynecek
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Abstract
Disclosed is a method for etching a tin oxide layer (18). The tin oxide layer (18) is masked by selectively forming an etchant-resistant material (20) on it. This material is itself patterned and etched, and then the exposed tin oxide (26) is isotropically etched such that substantially all of the exposed tin oxide (26) is removed. The preferred etchant of the invention comprises a major portion of inert nitrogen gas with a minor portion of hydrogen iodide. A vertical wall reactor (48) is provided for use with the invention in order to achieve a uniform flow and etch rate. In an alternate embodiment, a plasma reactor can be used to perform the etching.
Claims26
A method for etching a tin oxide layer deposited on a surface, comprising the steps of:
- masking the tin oxide layer by selectively forming an etchant-resistant material thereon;
- and
- isotropically etching the tin oxide layer with a gas etchant, such that substantially all of the exposed tin oxide is removed.
A method for forming a tin oxide structure on a surface of a semiconductor chip, comprising the steps of:
- depositing a tin oxide layer on the surface;
- depositing a hydrogen iodide-resistant layer on the tin oxide layer;
- patterning and etching the hydrogen iodide-resistant layer to form a mask for the tin oxide layer;
- and
- etching the tin oxide layer with a gas etchant having an active component comprising hydrogen iodide.
A composition for etching tin oxide, comprising:
- a minor proportion of hydrogen iodide gas;
- and
- a major proportion of an inert gas.
Apparatus for selectively etching a tin oxide layer on a semiconductor wafer, comprising:
- a vessel having an interior for holding at least one semiconductor wafer to be etched;
- a source of hydrogen iodide gas;
- a source of an inert gas;
- a mixer for mixing said hydrogen iodide gas and said inert gas to form a gas etchant;
- means for flowing the gas etchant from the mixer into the interior;
- and
- a temperature controller for regulating the temperature of the interior to between about 144.degree. C. and about 450.degree. C., such that the tin oxide layer is isotropically etched.
Dependencies are inferred from the claim text.