Field effect transistor with improved isolation structures
AssigneeTexas Instruments Incorporated
InventorsLily X. Springer, Binghua Hu, Chin-Yu Tsai, Jozef C. Mitros
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Abstract
An electronic device architecture is described comprising a field effect device in an active region 22 of a substrate 10. Channel stop implant regions 28a and 28b are used as isolation structures and are spaced apart from the active region 22 by extension zones 27a and 27b. The spacing is established by using an inner mask layer 20 and an outer mask layer 26 to define the isolation structures.
Claims13
A method of forming an electronic device in a semiconductor layer, comprising:
- forming an inner mask layer defining an active region on the outer surface of the semiconductor layer;
- implanting a first channel stop region into the semiconductor layer on the periphery of the inner mask layer;
- forming an outer mask layer covering the inner mask layer and portions of the outer surface of the semiconductor layer around the periphery of the inner mask layer, the portions of the semiconductor layer covered by the outer mask layer and not by the inner mask layer defining an extension zone;
- implanting a second channel stop region in the semiconductor layer around the periphery of the outer mask layer;
- removing the inner and outer mask layers;
- and
- forming an electronic device in the active region, the electronic device comprising implanted regions at the periphery of the active region, the implanted regions of the electronic device separated from the second channel stop region by at least the extension zone.
A method of forming an electronic device in a semiconductor layer, comprising:
- forming an inner mask layer defining an active region on the outer surface of the semiconductor layer;
- implanting a first channel stop region into the semiconductor layer on the periphery of the inner mask layer;
- forming an outer mask layer covering the inner mask layer and portions of the outer surface of the semiconductor layer around the periphery of the inner mask layer, the portions of the semiconductor layer covered by the outer mask layer and not by the inner mask layer defining an extension zone;
- implanting a second channel stop region in the semiconductor layer around the periphery of the outer mask layer;
- removing the inner and outer mask layers;
- forming an electronic device in the active region, the electronic device comprising implanted regions at the periphery of the active region, the implanted regions of the electronic device separated from the second channel stop region by at least the extension zone;
- and
- forming a field oxide layer proximate the first and the second channel stop regions prior to removing the inner mask layer but after removing the outer mask layer.
An electronic system formed in a semiconductor layer, comprising:
- a field effect transistor disposed in an active region of the outer surface of the semiconductor layer, the transistor comprising implanted regions proximate the periphery of the active region;
- a field oxide layer on the outer surface of the semiconductor layer abutting the periphery of at least a portion of the active region;
- and
- a channel stop implant region disposed in the semiconductor layer inwardly from portions of the field oxide layer and spaced apart from the periphery of the active region by an extension zone, the extension zone operable to inhibit the electrical interaction of the peripheral implanted regions of the transistor and the channel stop implant region.
Dependencies are inferred from the claim text.