James Fiorenza - Wilmington MA, US Anthony Lochtefeld - Ipswich MA, US Jie Bai - Bedford MA, US Ji-Soo Park - Methuen MA, US Jennifer Hydrick - Kingston NH, US Jizhong Li - Bordentown NJ, US Zhiyuan Cheng - Lincoln MA, US
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.
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.
Formation Of Devices By Epitaxial Layer Overgrowth
Zhiyuan Cheng - Lincoln MA, US James Fiorenza - Wilmington MA, US Jennifer M. Hydrick - Kingston NH, US Anthony J. Lochtefeld - Ipswich MA, US Ji-Soo Park - Methuen MA, US Jie Bai - Bedford MA, US Jizhong Li - Bordentown NJ, US
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.
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.