Method and program for calculating ion distribution

• US 20030236646A1
• Filed: 03/28/2003
• Published: 12/25/2003
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Suzuki, Kunihiro
• Granted Patent: US 7,149,667 B2
• Time in Patent Office: Days
• US Class Current: 702/179
• CPC Class Codes: G06F 30/23 using finite element methods [FEM] or finite difference methods [FDM]
• CPC Class Codes: H01J 2237/31703 Dosimetry

Abstract

A method and program for calculating ion distribution that reduce an error which will occur in the case of calculating ion distribution created by performing ion implantation on a crystalline member more than one time. An ion distribution specification step specifies existing ion distribution which has been created by performing ion implantation n (n is a natural number) times. An ion distribution assumption step assumes ion distribution which will be created by the (n+1)th ion implantation. A differential calculation step calculates the differential between the ion distribution, which will be created by the (n+1)th ion implantation and which is assumed by the ion distribution assumption step, and the existing ion distribution specified by the ion distribution specification step. An ion distribution calculation step calculates ion distribution created by the (n+1)th ion implantation by calculating the dose of ions implanted by the (n+1)th ion implantation from the differential calculated by the differential calculation step.

Claims

1. A method for calculating ion distribution in a crystalline member in the case of implanting ions in the member more than one time, the method comprising:

an ion distribution specification step for specifying existing ion distribution which has been created by performing ion implantation n (n is a natural number) times;

an ion distribution assumption step for assuming ion distribution which will be created by an (n+1)th ion implantation;

a differential calculation step for calculating differential between the ion distribution, which will be created by the (n+1)th ion implantation and which is assumed by the ion distribution assumption step, and the existing ion distribution specified by the ion distribution specification step; and

an ion distribution calculation step for calculating ion distribution created by the (n+1)th ion implantation by calculating dose of ions implanted by the (n+1)th ion implantation from the differential calculated by the differential calculation step.

2. The method for calculating ion distribution according to claim 1, wherein dose obtained by equally dividing entire dose into Nths (N≧

n) is used each time the ion implantation is performed.

3. The method for calculating ion distribution according to claim 1, wherein dose obtained by arbitrarily dividing entire dose is used each time the ion implantation is performed.

4. The method for calculating ion distribution according to claim 2, wherein more than one kind of ions are implanted in the ion implantation.

5. The method for calculating ion distribution according to claim 3, wherein more than one kind of ions are implanted in the ion implantation.

6. The method for calculating ion distribution according to claim 1, wherein:

the ion distribution specification step specifies existing ion distribution along an implantation path; and

the ion distribution calculation step calculates ion distribution created by the (n+1)th ion implantation along the implantation path.

7. The method for calculating ion distribution according to claim 1, wherein the ion distribution is ion distribution in an amorphous area and ion distribution in a channeling area.

8. The method for calculating ion distribution according to claim 1, wherein the crystalline member is a semiconductor substrate.

9. A computer readable program for making a computer calculate ion distribution in a crystalline member in the case of implanting ions in the member more than one time, the program making the computer function as:

an ion distribution specification step for specifying existing ion distribution which has been created by performing ion implantation n (n is a natural number) times;

an ion distribution assumption step for assuming ion distribution which will be created by an (n+1)th ion implantation;

a differential calculation step for calculating differential between the ion distribution, which will be created by the (n+1)th ion implantation and which is assumed by the ion distribution assumption step, and the existing ion distribution specified by the ion distribution specification step; and

an ion distribution calculation step for calculating ion distribution created by the (n+1)th ion implantation by calculating dose of ions implanted by the (n+1)th ion implantation from the differential calculated by the differential calculation step.