Silicon-on-insulator (SOI) structure configured for reduced harmonics and method of forming the structure
First Claim
1. A semiconductor structure comprise:
- a semiconductor substrate having a first surface and a second surface opposite said first surface, said semiconductor substrate comprising;
a first portion adjacent to said first surface and comprising, in a first concentration, a dopant having a given conductivity type such that said first portion has said given conductivity type; and
a second portion extending from said first portion to said second surface, said second portion comprising;
a plurality of microcavities; and
,in a second concentration greater than said first concentration, any of the following such that said second portion has said given conductivity type;
a same dopant as in said first portion,a different dopant than in said first portion, said different dopant having said given conductivity type, anda combination of said same dopant as in said first portion and said different dopant than in said first portion; and
an insulator layer on said semiconductor substrate immediately adjacent to said second surface.
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Accused Products
Abstract
Disclosed is semiconductor structure with an insulator layer on a semiconductor substrate and a device layer is on the insulator layer. The substrate is doped with a relatively low dose of a dopant having a given conductivity type such that it has a relatively high resistivity. Additionally, a portion of the semiconductor substrate immediately adjacent to the insulator layer can be doped with a slightly higher dose of the same dopant, a different dopant having the same conductivity type or a combination thereof. Optionally, micro-cavities are created within this same portion so as to balance out any increase in conductivity due to increased doping with a corresponding increase in resistivity. Increasing the dopant concentration at the semiconductor substrate-insulator layer interface raises the threshold voltage (Vt) of any resulting parasitic capacitors and, thereby reduces harmonic behavior. Also disclosed herein are embodiments of a method for forming such a semiconductor structure.
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Citations
8 Claims
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1. A semiconductor structure comprise:
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a semiconductor substrate having a first surface and a second surface opposite said first surface, said semiconductor substrate comprising; a first portion adjacent to said first surface and comprising, in a first concentration, a dopant having a given conductivity type such that said first portion has said given conductivity type; and a second portion extending from said first portion to said second surface, said second portion comprising; a plurality of microcavities; and
,in a second concentration greater than said first concentration, any of the following such that said second portion has said given conductivity type; a same dopant as in said first portion, a different dopant than in said first portion, said different dopant having said given conductivity type, and a combination of said same dopant as in said first portion and said different dopant than in said first portion; and an insulator layer on said semiconductor substrate immediately adjacent to said second surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification