Taiwan Semiconductor Manufacturing Comp. Ltd.

Jie Bai

Anthony J Lochtefeld

Ji-Soo Park

James Fiorenza

Jizhong Li

Jennifer M Hydrick

Zhiyuan Cheng

Zhinyuan Cheng

Cheng Zhiyuan

Methods and structures are provided for formation of devices, e.g., solar cells, on substrates including, e.g., lattice-mismatched materials, by the use of aspect ratio trapping and epitaxial layer overgrowth. A method includes forming an opening in a masking layer disposed over a substrate that includes a first semiconductor material. A first layer, which includes a second semiconductor material lattice-mismatched to the first semiconductor material, is formed within the opening. The first layer has a thickness sufficient to extend above a top surface of the masking layer. A second layer, which includes the second semiconductor material, is formed on the first layer and over at least a portion of the masking layer. A vertical growth rate of the first layer is greater than a lateral growth rate of the first layer and a lateral growth rate of the second layer is greater than a vertical growth rate of the second layer.

Formation of devices by epitaxial layer overgrowth

Lattice-mismatched epitaxial films formed proximate non-crystalline sidewalls. Embodiments of the invention include formation of facets that direct dislocations in the films to the sidewalls.

Defect reduction using aspect ratio trapping

Methods and structures are provided for formation of devices on substrates including, e.g., lattice-mismatched materials, by the use of aspect ratio trapping and epitaxial layer overgrowth. A method includes forming an opening in a masking layer disposed over a substrate that includes a first semiconductor material. A first layer, which includes a second semiconductor material lattice-mismatched to the first semiconductor material, is formed within the opening. The first layer has a thickness sufficient to extend above a top surface of the masking layer. A second layer, which includes the second semiconductor material, is formed on the first layer and over at least a portion of the masking layer. A vertical growth rate of the first layer is greater than a lateral growth rate of the first layer and a lateral growth rate of the second layer is greater than a vertical growth rate of the second layer.

Methods and structures are provided for formation of devices, e.g., solar cells, on substrates including, e.g., lattice-mismatched materials, by the use of aspect ratio trapping (ART) and epitaxial layer overgrowth (ELO). In general, in a first aspect, embodiments of the invention may include a method of forming a structure. The method includes forming a first opening in a masking layer disposed over a substrate that includes a first semiconductor material. A first layer, which includes a second semi-conductor material lattice-mismatched to the first semiconductor material, is formed within the first opening. The first layer has a thickness sufficient to extend above a top surface of the masking layer. A second layer, which includes the second semiconductor material, is formed on the first layer and over at least a portion of the masking layer. A vertical growth rate of the first layer is greater than a lateral growth rate of the first layer and a lateral growth rate of the second layer is greater than a vertical growth rate of the second layer.

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Bedford, NH, United States of America

Jie Bai