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US 8,173,551 B2Granted
Defect reduction using aspect ratio trapping
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJie Bai, Ji-Soo Park, Anthony J. Lochtefeld
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Abstract
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.
Claims22
A method for forming a structure, the method comprising the steps of:
- providing a crystalline semiconductor substrate comprising a first semiconductor material and having a top surface;
- defining an opening having a non-crystalline sidewall proximate the top surface of the crystalline semiconductor substrate;
- and
- forming an epitaxial film in the opening, the epitaxial film comprising a second semiconductor material and including a growth front, the growth front including a surface comprising a facet not parallel to the substrate top surface, the second semiconductor material being lattice-mismatched to the first semiconductor material, wherein a dislocation in the epitaxial film propagates in a first direction within 10° of normal to the facet, the dislocation intersecting the non-crystalline sidewall in the first direction.
1 more element
A method for forming a structure, the method comprising the steps of:
- defining an opening in a dielectric material disposed over a crystalline semiconductor substrate comprising a first semiconductor material;
- and
- forming an epitaxial film in the opening, the epitaxial film (i) comprising a second semiconductor material lattice-mismatched to the first semiconductor material, and (ii) including a growth front having a surface, a dislocation in the epitaxial film propagating in a direction within 10° of perpendicular to the growth front surface, the dislocation terminating at a sidewall of the opening and with a termination angle defined in part by the direction within 10° of perpendicular to the growth front surface, wherein the growth front surface defines an acute angle α with a top surface of the substrate such that the epitaxial film growth front surface is substantially non-parallel to a top surface of the substrate, and an aspect ratio H of a height h of the opening to a width w of the opening is greater than or equal to (tan α+1/tan α)/2, wherein the height h is in a direction normal to the top surface of the substrate, and the width w is in a direction parallel to the top surface of the substrate.
A method for forming a structure;
- the method comprising the steps of:
- defining a trench having a longitudinal axis and a dielectric sidewall disposed adjacent a substrate comprising a first semiconductor material;
- and
- epitaxially growing a second semiconductor material in the trench, the second semiconductor material being lattice mismatched to the first semiconductor material,
- wherein defects arising from the lattice mismatch between the first and second semiconductor materials propagate away from the longitudinal axis of the trench in a direction substantially perpendicular to a growth front of the second material and are trapped by a sidewall of the trench, wherein the defects intersect the sidewall in the direction substantially perpendicular to the growth front.
2 more elements
A method for forming a structure, the method comprising the steps of:
- performing a selective etch to expose a crystal plane of a crystalline substrate including a first semiconductor material;
- forming a dielectric layer over the substrate;
- defining an opening in the dielectric layer to reveal the exposed crystal plane;
- and
- forming a second semiconductor material in the opening, wherein dislocations propagate away from a center of the opening in a plane approximately normal to a growth surface of the second semiconductor material, the dislocations terminating at a sidewall of the opening, the dislocations terminating at an angle defined by the plane approximately normal to the growth surface and the sidewall of the opening.
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Dependencies are inferred from the claim text.