Reducing Stress in Semiconductor Layers with Alternating Growth
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Summary
Problems
Heteroepitaxy of group III-nitride semiconductor films over foreign substrates results in high dislocation density and stress, which hinders the efficiency of light emitting devices like LEDs, particularly deep ultraviolet LEDs, as existing methods fail to achieve uniform composition and effective stress management.
Innovation solutions
A method involving epitaxial growth periods where alternating semiconductor layers with tensile and compressive stresses are grown, incorporating specific dopants to manage stress, resulting in a semiconductor structure with reduced residual stress, cracks, and dislocations.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If heteroepitaxy of group III-nitride semiconductor films is grown over foreign substrates, then the semiconductor layers can be formed, but high dislocation density and stress are generated
Why choose this principle:
The patent divides the semiconductor structure into alternating layers of first and second semiconductor materials with different lattice constants. This segmentation creates a superlattice structure where each layer compensates for stress in the other, effectively reducing overall dislocation density and stress accumulation in the epitaxial layers grown on foreign substrates.
Principle concept:
If heteroepitaxy of group III-nitride semiconductor films is grown over foreign substrates, then the semiconductor layers can be formed, but high dislocation density and stress are generated
Why choose this principle:
The patent changes the lattice constant parameter by alternating between two different semiconductor materials with distinct lattice constants. This parameter variation enables stress compensation mechanisms where the expansion in one layer compensates for compression in the other, reducing net stress and dislocation density in the structure.
Application Domain
Data Source
AI summary:
A method involving epitaxial growth periods where alternating semiconductor layers with tensile and compressive stresses are grown, incorporating specific dopants to manage stress, resulting in a semiconductor structure with reduced residual stress, cracks, and dislocations.
Abstract
A solution for fabricating a semiconductor structure and the corresponding semiconductor structure are provided. The semiconductor structure includes a plurality of semiconductor layers grown over a substrate using a set of epitaxial growth periods. During each epitaxial growth period, a first semiconductor layer having one of: a tensile stress or a compressive stress is grown followed by growth of a second semiconductor layer having the other of: the tensile stress or the compressive stress directly on the first semiconductor layer.