Phase-change memory cell having a compact structure
First Claim
1. A memory cell comprising:
- a semiconductor substrate;
a first insulating layer covering a surface of the semiconductor substrate;
an active layer of semiconductor material covering the first insulating layer;
a control gate of a selection transistor, the control gate being formed on the active layer and having a lateral flank;
a trench formed through the active layer, the trench being defined on one side by a lateral flank of the active layer and defined on a bottom side by a top side of the first insulating layer;
a second insulating layer covering the lateral flank of the control gate; and
a variable-resistance element electrically coupled to a first conduction terminal of the selection transistor,wherein the variable-resistance element is at least partially in the trench and contacting the lateral flank of the active layer in the trench.
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Accused Products
Abstract
A memory cell includes a selection transistor having a control gate and a first conduction terminal connected to a variable-resistance element. The memory cell is formed in a wafer comprising a semiconductor substrate covered with a first insulating layer, the insulating layer being covered with an active layer made of a semiconductor. The gate is formed on the active layer and has a lateral flank covered with a second insulating layer. The variable-resistance element includes a first layer covering a lateral flank of the active layer in a trench formed through the active layer along the lateral flank of the gate and reaching the first insulating layer, and a second layer made of a variable-resistance material.
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Citations
21 Claims
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1. A memory cell comprising:
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a semiconductor substrate; a first insulating layer covering a surface of the semiconductor substrate; an active layer of semiconductor material covering the first insulating layer; a control gate of a selection transistor, the control gate being formed on the active layer and having a lateral flank; a trench formed through the active layer, the trench being defined on one side by a lateral flank of the active layer and defined on a bottom side by a top side of the first insulating layer; a second insulating layer covering the lateral flank of the control gate; and a variable-resistance element electrically coupled to a first conduction terminal of the selection transistor, wherein the variable-resistance element is at least partially in the trench and contacting the lateral flank of the active layer in the trench. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A memory comprising:
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a plurality of wordlines; a plurality of bit lines; a plurality of source lines; a semiconductor substrate; a first insulating layer covering a surface of the semiconductor substrate; a semiconductor active layer covering the first insulating layer; and at least two memory cells, each of the memory cells including; a selection transistor that includes a control gate and a first conduction terminal, the control gate being formed on the active layer, having a lateral flank, and being electrically coupled to one of the word lines; a trench formed through the active layer, the trench being defined on one side by a lateral flank of the active layer and defined on a bottom side by a top side of the first insulating layer; a second insulating layer covering the lateral flank of the control gate; and a variable-resistance element electrically coupled to the first conduction terminal of the selection transistor, wherein the variable-resistance element is at least partially in the trench and contacting the lateral flank of the active layer in the trench, the conduction terminal of the selection transistor being electrically coupled to one of the bit lines through the variable-resistance element. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A memory comprising:
a first memory cell that includes; a selection transistor having a control gate formed on a semiconductor layer and a first conduction terminal formed in the semiconductor layer, the control gate having a lateral flank; a first insulating layer covering the lateral flank of the control gate; and a variable-resistance element electrically coupled to and in contact with the first conduction terminal of the selection transistor at a lateral flank of the semiconductor layer, the variable-resistance element extending through the semiconductor layer and covering a lateral flank of the first insulating layer, the first insulating layer extending between the control gate and the variable-resistance element and electrically insulating the control gate from the variable-resistance element. - View Dependent Claims (16, 17, 18, 19, 20, 21)
Specification