Method for controlling the oxidation of implanted silicon
AssigneeCypress Semiconductor Corporation
InventorsKrishnaswamy Ramkumar, Hanna Bamnolker
Life of this patent
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Abstract
Two different regions of a semiconductor substrate are implanted with dopants/ions. The implantation may occur though a sacrificial oxide layer disposed over the substrate. Following implantation in one or both regions, the substrate may be annealed and the sacrificial oxide layer removed. An oxide layer is then grown over the implanted regions of the substrate. For some embodiments, the substrate may be implanted with arsenic and/or with phosphorus. Further, the anneal may be performed for approximately 30 to 120 minutes at a temperature between approximately 900° C. and 950° C.
Claims18
A method, comprising:
- implanting with from 5×1013 to 1019 atoms/cm3 of a first dopant of a first conductivity into a first active region of a semiconductor die;
- implanting with from 5×1013 to 1019 atoms/cm3 of a second different dopant of said first conductivity into a second, separate active region of said semiconductor die;
- annealing said semiconductor die sufficiently to reduce a difference in oxidation rates of said first and second active regions;
- and
- simultaneously growing a gate oxide layer over said first and second active regions of said semiconductor die, to different thicknesses.
A method, comprising:
- implanting a first active region of a semiconductor die with from 5×1013 to 1019 atoms/cm3 of a first dopant of a first conductivity type;
- followed by
- implanting a second separate active region of said semiconductor die with from 5×1013 to 1019 atoms/cm3 of a second different dopant of said first conductivity type;
- followed by
- annealing said semiconductor die at a temperature of at least 700° C.;
- followed by
- growing a gate oxide layer over said first active region and said second active region, to different thicknesses, at the same time.
A method, comprising:
- implanting with from 5×1013 to 1019 atoms/cm3 of a first dopant of a first conductivity type through a sacrificial oxide layer into a first active region of a semiconductor die;
- implanting with from 5×1013 to 1019 atoms/cm3 of a second different dopant of said first conductivity type through said sacrificial oxide layer into a second, separate active region of said semiconductor die;
- annealing said semiconductor die sufficiently to reduce a difference in oxidation rates of said first and second active regions;
- removing said sacrificial oxide layer from over at least one of said first and second active regions;
- and
- simultaneously growing a gate oxide layer over said first and second active regions of said semiconductor die, to different thicknesses.
Dependencies are inferred from the claim text.