Method of laser annealing of subsurface ion implanted regions
AssigneeInternational Business Machines Corporation
InventorsHoward H. Hansen, Jerome B. Lasky, Ronald R. Silverman
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Abstract
A method for annealing ion implanted regions buried in a semiconductor substrate without the undesirable effects of thermal diffusion which includes the radiation of the substrate by a continuous laser having an emission frequency longer than 600 nanometers which the buried ion implanted regions will absorb strongly but which will be substantially unabsorbed by the unimplanted regions. Superior results can be obtained when the substrate is heated to approximately 300.degree. during this laser annealing.
Claims9
A method of annealing buried ion implanted regions in a semiconductor body comprising;
- ion implanting impurity ions into a crystalline semiconductor body to provide in the body a buried region having a high concentration of said impurity ions at a predetermined depth below the surface, and
- annealing said buried region by exposure of the body to the emission of a continuous wave laser having an emission frequency which is substantially absorbed by the buried region and to which the remainder of the body is substantially transparent to cause electrical activation of the implanted ions in said buried region without substantial thermal diffusion of the implanted species.
A method of annealing buried ion implantated regions in a semiconductor body without undesirable effects of thermal diffusion of said implanted region by a continuous laser having an emission frequency at which said ion implanted regions absorb strongly and at which the unimplanted regions are substantially unabsorbed to cause electrical activation of the implanted ions in said region without substantial thermal diffusion of the implanted ions and heating the body to approximately 300.degree. C. during exposure of the body to said laser to eliminate the effects of any instability in said laser.
A method of forming and annealing deep buried ion implanted regions in a semiconductor body comprising;
- ion implanting impurity ions into a crystalline semiconductor body to provide a buried region having its highest concentration of impurity ions at a predetermined depth of at least 0.35 microns below the surface of the body, and
- annealing the buried region by exposure of said body to the light emitted by a continuous wave laser having an emission frequency greater than 600 nanometers to which the unimplanted body is substantially transparent but which is substantially absorbed by the buried region.
Dependencies are inferred from the claim text.