Trench Schottky diode and method for manufacturing the same
First Claim
1. A method for manufacturing a trench Schottky diode, comprising steps of:
- providing a semiconductor substrate having a first surface;
forming a first mask layer on the first surface, wherein the first mask layer includes a first plurality of openings and a second plurality of opening;
forming a first plurality of trenches and a second plurality of trenches in the semiconductor substrate according to the first mask layer;
forming a first plurality of gate oxide layers correspondingly formed on surfaces of the first plurality of trenches and a second plurality of gate oxide layers correspondingly formed on surfaces of the second plurality of trenches, wherein the first plurality of gate oxide layers and the second plurality of gate oxide layers protrude above the first surface of the semiconductor substrate;
filling a first plurality of polysilicon structures in the first plurality of trenches and a second plurality of polysilicon structures in the second plurality of trenches, wherein the first plurality of polysilicon structures and the second plurality of polysilicon structures protrude above the first surface of the semiconductor substrate;
forming a second mask layer covering mask layer, the first plurality of polysilicon structures and the second plurality of polysilicon structures;
removing a portion of the first mask layer and a portion of the second mask layer, wherein a remained portion of the first mask layer is on a portion of the first surface among the first plurality of trenches and covers the first surface among the first plurality of trenches and the first plurality of gate oxide layers, and wherein a remained portion of the second mask layer is on the remained portion of the first mask layer and the first plurality of polysilicon structures, and completely covers the remained portion of the first mask layer; and
forming an electrode on the other portion of the first surface, the remained portion of the second mask layer, the second plurality of the protruding polysilicon structures and the second plurality of the protruding gate oxide layers.
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Accused Products
Abstract
A trench Schottky diode and its manufacturing method are provided. The trench Schottky diode includes a semiconductor substrate having therein a plurality of trenches, a gate oxide layer, a polysilicon structure, a guard ring and an electrode. At first, the trenches are formed in the semiconductor substrate by an etching step. Then, the gate oxide layer and the polysilicon structure are formed in the trenches and protrude above a surface of the semiconductor substrate. The guard ring is formed to cover a portion of the resultant structure. At last, the electrode is formed above the guard ring and the other portion not covered by the guard ring. The protruding gate oxide layer and the protruding polysilicon structure can avoid cracks occurring in the trench structure.
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Citations
12 Claims
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1. A method for manufacturing a trench Schottky diode, comprising steps of:
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providing a semiconductor substrate having a first surface; forming a first mask layer on the first surface, wherein the first mask layer includes a first plurality of openings and a second plurality of opening; forming a first plurality of trenches and a second plurality of trenches in the semiconductor substrate according to the first mask layer; forming a first plurality of gate oxide layers correspondingly formed on surfaces of the first plurality of trenches and a second plurality of gate oxide layers correspondingly formed on surfaces of the second plurality of trenches, wherein the first plurality of gate oxide layers and the second plurality of gate oxide layers protrude above the first surface of the semiconductor substrate; filling a first plurality of polysilicon structures in the first plurality of trenches and a second plurality of polysilicon structures in the second plurality of trenches, wherein the first plurality of polysilicon structures and the second plurality of polysilicon structures protrude above the first surface of the semiconductor substrate; forming a second mask layer covering mask layer, the first plurality of polysilicon structures and the second plurality of polysilicon structures; removing a portion of the first mask layer and a portion of the second mask layer, wherein a remained portion of the first mask layer is on a portion of the first surface among the first plurality of trenches and covers the first surface among the first plurality of trenches and the first plurality of gate oxide layers, and wherein a remained portion of the second mask layer is on the remained portion of the first mask layer and the first plurality of polysilicon structures, and completely covers the remained portion of the first mask layer; and forming an electrode on the other portion of the first surface, the remained portion of the second mask layer, the second plurality of the protruding polysilicon structures and the second plurality of the protruding gate oxide layers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification