Method of forming nondefective zone in silicon single crystal wafer by two stage-heat treatment
AssigneeVLSI Technology Research Association
InventorsKazuhiko Yamamoto, Yoshiaki Matsushita, Masaru Kanamori, Kazutoshi Nagasawa, Naotsugu Yoshihiro, Seigo Kishino
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Abstract
A silicon single crystal wafer is subjected to two-stage heat treatment. In the first-stage it is heated at a temperature within the range of between 500.degree. C. and 1,000.degree. C. Subsequently the thus heated wafer is heated at a temperature higher than that at the first stage. Thus, a nondefective zone is formed in the surface region of the wafer, and the interior zone of the wafer becomes rich in micro defects capable of gettering impurities such as heavy metals.
Claims13
A method of forming a nondefective zone in a silicon single crystal wafer comprising:
- a first-stage heat treatment of heating the wafer for ten (10) to one hundred (100) hours at a temperature within the range of between 500.degree. C. and 1000.degree. C. to form a number of defect-causing nuclei within the wafer;
- and
- a second-stage heat treatment of heating the thus treated wafer at a temperature higher than that used in the first-stage, thereby converting the surface region of the wafer into a nondefective zone and forming a micro defect-rich zone at the interior center region of the wafer, the defect-causing nuclei being mainly involved in the formation of the micro defects in the second-stage heat treatment.
A method of forming a nondefective zone in a silicon single crystal wafer comprising:
- a first-stage heat treatment of heating the wafer for ten (10) to one hundred (100) hours at a temperature within the range of between 500.degree. C. and 800.degree. C. to form a number of defect causing nuclei within the wafer;
- and
- a second-stage heat treatment of heating the thus treated wafer at a temperature higher than that used in the first-stage, thereby converting the surface region of the wafer into a nondefective zone and forming a micro defect-rich zone at the interior center region of the wafer, the defect causing nuclei being mainly involved in the formation of the micro defects in the second-stage heat treatment.
Dependencies are inferred from the claim text.