Ultra-shallow semiconductor junction formation

Claim 1

A method of forming a shallow junction in a semiconductor material comprising the steps of: (a) irradiating a surface of a semiconductor material with a first ion at a first irradiation energy so as to form a damaged region at a first depth; (b) irradiating said surface with a dopant ion at a second irradiation energy so as to form a dopant region at a second depth which is less than the first depth; and (c) heating said semiconducting material by a single annealing step which is a rapid thermal annealing process so as to cause substantial annealing of said dopant ion within said semiconducting material and to prevent substantial diffusion of said dopant ion to a depth greater than said second depth, thereby forming an ultra-shallow junction in said semiconductor material having a depth of about 50 nm or less having a boundary with said semiconductor material that changes by a factor of 10 within a distance of less thin 60 Å, measured at, and perpendicular to, said boundary, said single rapid thermal annealing process comprising (i) heating said semiconductor material from room temperature to a temperature of from about 850° C. to about 1100° C. at a rate of from about 50° C./sec to about 1000° C./sec, (ii) maintaining said temperature for a time period of from about 1 millisecond to about 5 seconds and (iii) cooling said semiconductor material to room temperature at a cooling rate of about 50° C./sec to about 1000° C./sec.

Claim 2

A method of forming a shallow junction in a semiconductor material comprising the steps of: (a) irradiating a surface of a semiconductor material with a first ion at a first irradiation energy so as to form a damaged region at a first depth; (b) irradiating said surface with a dopant ion at a second irradiation energy so as to form a dopant region at a second depth which is less than the first depth; and (c) heating said semiconducting material by a single annealing step which is a rapid thermal annealing process so as to cause substantial annealing of said dopant ion within said semiconducting material and to prevent substantial diffusion of said dopant ion to a depth greater than said second depth, thereby forming an ultra-shallow junction in said semiconductor material having a depth of about 50 nm or less having a boundary with said semiconductor material that changes by a factor of 10 within a distance of less thin 60 Å, measured at, and perpendicular to, said boundary, said single rapid thermal annealing process comprising (i) heating said semiconductor material from room temperature to a temperature of from about 850° C. to about 1100° C. at a rate of from about 50° C./sec to about 1000° C./sec, (ii) maintaining said temperature for a time period of from about 1 millisecond to about 5 seconds and (iii) cooling said semiconductor material to room temperature at a cooling rate of about 50° C./sec to about 1000° C./sec.