Method of manufacturing a semiconductor device comprising an insulated gate field effect device
First Claim
1. A method of manufacturing a semiconductor device comprising an insulated gate field effect device, which method comprises providing a semiconductor body having first and second major surfaces with a first region of one conductivity type separated from the first major surface by a second region of the opposite conductivity type, providing on the one major surface a mask defining at least one window, etching the semiconductor body through the window to define a groove extending through the second region into the first region, providing a layer of gate insulator on the surface of the groove, providing a gate conductive region of an oxidizable conductive material within the groove to define with the gate insulator layer an insulated gate structure bounded by a conduction channel-defining area of the second region, causing the insulated gate structure to extend beyond the surrounding semiconductor surface to define at least one step in the surface structure by oxidizing the exposed conductive material to define an insulating capping region over the exposed surface of the gate conductive region and then providing a layer over the surface structure, etching the layer anisotropically to leave portions of the layer on the sidewall of the steps defined by the insulated gate structure and to define beneath the portions third regions of the one conductivity type within the second region, and depositing an electrically conductive layer to contact both the second and the third regions.
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Accused Products
Abstract
A mask (4) defining at least one window (4a) is provided on one major surface (1a) of a semiconductor body (1). The semiconductor body (1) is etched to define a groove (5) into a first region (2) of one conductivity type through a second region (3) of the opposite conductivity type. A relatively thin layer of gate insulator (6) is provided on the surface (5a) of the groove (5). A gate conductive region (7) of an oxidizable conductive material is provided within the groove (5) to define with the gate insulator layer an insulated gate structure (8) bounded by a conduction channel-defining area (30) of the second region (3). A step (15) in the surface structure is then defined by causing the insulated gate structure (8) to extend beyond the surrounding surface by oxidizing the exposed (7a) gate conductive material to define an insulating capping region (9) on the gate conductive region (3). A layer (10) is formed over the surface structure and etched anisotropically to leave portions (10a) of the layer on the side wall (8'"'"'a) of the step (15) defined by the insulated gate structure (8) and to define beneath the portions (10a) third regions (11) of the one conductivity type within the second region (3). An electrically conductive layer (12) is deposited to contact both the second and the third regions (3 and 11).
123 Citations
17 Claims
- 1. A method of manufacturing a semiconductor device comprising an insulated gate field effect device, which method comprises providing a semiconductor body having first and second major surfaces with a first region of one conductivity type separated from the first major surface by a second region of the opposite conductivity type, providing on the one major surface a mask defining at least one window, etching the semiconductor body through the window to define a groove extending through the second region into the first region, providing a layer of gate insulator on the surface of the groove, providing a gate conductive region of an oxidizable conductive material within the groove to define with the gate insulator layer an insulated gate structure bounded by a conduction channel-defining area of the second region, causing the insulated gate structure to extend beyond the surrounding semiconductor surface to define at least one step in the surface structure by oxidizing the exposed conductive material to define an insulating capping region over the exposed surface of the gate conductive region and then providing a layer over the surface structure, etching the layer anisotropically to leave portions of the layer on the sidewall of the steps defined by the insulated gate structure and to define beneath the portions third regions of the one conductivity type within the second region, and depositing an electrically conductive layer to contact both the second and the third regions.
Specification