FinFET with oxidation-induced stress
AssigneeInternational Business Machines Corporation
InventorsKangguo Cheng, Bruce B. Doris, Ali Khakifirooz, Kern Rim
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Abstract
A method for inducing stress within the channel of a semiconductor fin structure includes forming a semiconductor fin on a substrate; forming a fin hard mask layer, multiple isolation regions, and multiple spacers, on the semiconductor fin; forming a gate structure on the semiconductor fin; and oxidizing multiple outer regions of the semiconductor fin to create oxidized stressors that induce compressive stress within the channel of the semiconductor fin. A method for inducing tensile stress within the channel of a semiconductor fin by oxidizing a central region of the semiconductor fin is also provided. Structures corresponding to the methods are also provided.
Claims12
A method for constructing a semiconductor fin structure having a compressive stressed channel, the method comprising:
- forming a semiconductor fin on a substrate;
- forming a fin hard mask layer on a top surface of the semiconductor fin;
- forming a first isolation region on a lower portion of a first side wall of the semiconductor fin;
- forming a second isolation region on a lower portion of a second side wall of the semiconductor fin;
- forming a first fin spacer on an upper portion of the first side wall of the semiconductor fin;
- forming a second fin spacer on an upper portion of the second side wall of the semiconductor fin;
- forming a gate structure on a center portion of the semiconductor fin;
- oxidizing a first lower outer region of the semiconductor fin through the width of the fin to create a first oxide stressor that is separated from the top surface of the semiconductor fin by an upper portion of the semiconductor fin;
- and
- oxidizing a second lower outer region of the semiconductor fin through the width of the semiconductor fin to create a second oxide stressor that is separated from the top surface of the semiconductor fin by an upper portion of the fin, and separated from the first stressor by the center portion of the semiconductor fin;
- wherein oxidizing the first lower outer region causes the first lower outer region to expand thereby forming the first oxide stressor, which exerts vertical pressure on the upper portion of the semiconductor fin directly above the first stressor;
- wherein oxidizing the second lower outer region causes the second lower outer region to expand thereby forming the second oxide stressor, which exerts vertical pressure on the upper portion of the semiconductor fin directly above the second stressor;
- and
- wherein the first oxide stressor and the second oxide stressor collectively induce compressive stress within a channel of the semiconductor fin.
A semiconductor fin structure having a compressive stressed channel, the semiconductor fin structure comprising:
- a semiconductor fin having a channel;
- a first oxide stressor formed through the width of the semiconductor fin, separated from a top surface of the semiconductor fin by an upper portion of the semiconductor fin;
- and
- a second oxide stressor formed through the width of the semiconductor fin, separated from a top surface of the semiconductor fin by an upper portion of the semiconductor fin, and separated from the first stressor by a center portion of the semiconductor fin;
- wherein the first oxide stressor exerts vertical pressure on the upper portion of the semiconductor fin directly above the first oxide stressor, and the second oxide stressor exerts vertical pressure on the upper portion of the semiconductor fin directly above the second oxide stressor, such that the first oxide stressor and the second oxide stressor collectively induce compressive stress within the channel of the semiconductor fin.
Dependencies are inferred from the claim text.