PATENT CLAIM ANALYSIS

Application Number: 16069927
Application Type: Utility
Filing Date: 2018-07
Publication Date: 2019-01
Patent Classification: ["257", "077000"]

Abstract:
A method for manufacturing a compound semiconductor device includes: providing a semiconductor substrate that includes a foundation layer; forming a deep trench in the foundation layer; and filling the deep trench with a deep layer having a second conductive type and a limiting layer having the first conductive type. In the filling the deep trench, growth of the deep layer from a bottom of the deep trench toward an opening inlet of the deep trench and growth of the limiting layer from a side face of the deep trench are achieved by: dominant epitaxial growth of a second conductive type layer over a first conductive type layer on the bottom of the deep trench; and dominant epitaxial growth of the first conductive type layer over the second conductive type layer on the side face of the deep trench, based on plane orientation dependency of the compound semiconductor during epitaxial growth.

Claim (Index 10):
A compound semiconductor device comprising a vertical MOSFET that includes:\n a semiconductor substrate that is formed of a compound semiconductor, and includes a rear face layer disposed on a rear face side of the semiconductor substrate and a drift layer having a first conductive type and disposed on a front face side of the semiconductor substrate, the rear face layer having a higher impurity concentration and the drift layer having an impurity concentration lower than the rear face layer; a current diffusion layer that has the first conductive type, is disposed on the drift layer, and is formed of a compound semiconductor having an impurity concentration higher than the drift layer; a base area that is disposed on the drift layer and is formed of a compound semiconductor; a source area that is disposed above the base area and is formed of a compound semiconductor having the first conductive type and an impurity concentration higher than the drift layer; a trench gate structure that is disposed in a trench extending from a front face of the source area to a position deeper than the base area, and includes a gate insulation film disposed on an inner wall surface of the trench and a gate electrode disposed on the gate insulation film; a source electrode that is electrically connected to the source area; and a drain electrode that is electrically connected to the rear face layer disposed on the rear face side of the semiconductor substrate, wherein the compound semiconductor device further comprises:\n a deep trench that penetrates the source area, the base area, and the current diffusion layer, and reaches the drift layer; \n a deep layer that has a second conductive type and is located below the base area in the deep trench; \n a limiting layer that has the first conductive type, limits a depletion layer extending from a side face of the deep layer to the drift layer, and is disposed on a side face of the deep trench; and \n a contact layer that has the second conductive type, is located above the deep layer and the limiting layer in the deep trench, and is in contact with the base area and the source electrode.

Metadata:
- Claim Count in Document: 11.0
- Percentile: 95.0
- Lexical Diversity: 2.89091
- Patent Class: 257.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['16069914', '16069622', '16070061', '14894668', '15570841']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.9272393183019532
- 35 USC 102 Novelty (BERT): 0.549076259198659
- Combined Prediction Score: 0.8894230123916238
- Mean Citation Score: 328.5816660000001
- Max Citation Score: 415.10687
- Similarity Product: 352.8100204941964

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test