Semiconductor substrate for solid-state image sensing device as well as solid-state image sensing device and method for producing the same
AssigneeSumco Corporation
InventorKazunari Kurita
Life of this patent
Estimating the term…
Abstract
There is provided a semiconductor substrate for solid-state image sensing device in which the production cost is lower than that of a gettering method through a carbon ion implantation and problems such as occurrence of particles at a device production step and the like are solved. Silicon substrate contains solid-soluted carbon having a concentration of 1×1016-1×1017 atoms/cm3 and solid-soluted oxygen having a concentration of 1.4×1018-1.6×1018 atoms/cm3.
Claims5
A semiconductor substrate for a solid-state image sensor, comprising:
- an epitaxial layer of silicon, existent on a silicon substrate;
- and an oxide film existent on the epitaxial layer;
- wherein the silicon substrate contains solid-soluted carbon having a concentration of 3×1016-8×1016 atoms/cm3 and solid-soluted oxygen having a concentration of 1.4×1018-1.6×1018 atoms/cm3;
- wherein carbon-oxygen based precipitates having a size in the range of 75 nm to 180 nm (inclusive of 75 nm and 180 nm) are existent in the silicon substrate at a density of 1×107-1×108 precipitates/cm2.
A method for producing a semiconductor substrate for solid-state image sensing device, comprising:
- growing an epitaxial layer of silicon on a silicon substrate produced from a single silicon crystal containing solid-soluted carbon at a concentration of 3×1016-8×1016 atoms/cm3 and solid-soluted oxygen at a concentration of 1.4×1018-1.6×1018 atoms/cm3;
- growing an oxide film on the epitaxial layer;
- subjecting the resulting silicon substrate to a low temperature heat treatment of 600° C. to 700° C. such that carbon-oxygen based precipitates having a size in the range of 75 nm to 180 nm (inclusive of 75 nm and 180 nm) are existent in the silicon substrate at a density of 1×107-1×108 precipitates/cm2.
A solid-state image sensing device comprising:
- a silicon substrate;
- and
- a buried-type photodiode formed thereon;
- wherein carbon-oxygen based precipitates having a size in the range of 75 nm to 180 nm (inclusive of 75 nm and 180 nm) are existent in the silicon substrate at a density of 1×107-1×108 precipitates/cm2.
Dependencies are inferred from the claim text.