US 6,154,717 A · Computer simulation method of impurity with pileup phenomenon

Abstract

A simulation method is provided, which makes it possible to simulate diffusion of doped impurity in Si and SiO.sub.2 in consideration of the pileup phenomenon of the doped impurity without using any intermediate layer. In the step (a), a mesh having mesh points is configured on a simulated zone including a SiO.sub.2 region and a Si region contracted therewith, thereby partitioning the simulated zone into domains. A first one of the mesh points is located in a SiO.sub.2 region. A second one of the mesh points is located in a Si region. A third one of the mesh points is located at an interface of the SiO.sub.2 and Si regions. The third one of the mesh points serves as a double mesh point having first and second impurity concentrations. The first impurity concentration represents a general impurity concentration of a first one of the domains located in the SiO.sub.2 region and adjacent to the interface of the SiO.sub.2 and Si regions. The second impurity concentration represents a general impurity concentration of a second one of the domains located in the Si region and adjacent to the interface of the SiO.sub.2 and Si regions. In the step (b), diffusion equations are provided at the respective mesh points in such a way that the doped impurity piles up in the first one of the domains located in the SiO.sub.2 region. In the step (c), the diffusion equations are solved.

Claims20

Dependent claims

A simulation method of diffusion of a doped impurity, comprising the steps of:

(a) configuring a mesh having mesh points on a simulated zone including a SiO.sub.2 region and a Si region contacted therewith, thereby partitioning said simulated zone into domains;
a first one of said mesh points being located in a SiO.sub.2 region;
a second one of said mesh points being located in a Si region;
a third one of said mesh points being located at an interface of said SiO.sub.2 and Si regions;
said third one of said mesh points serving as a double mesh point having first and second impurity concentrations;
said first impurity concentration representing a general impurity concentration of a first one of said domains located in said SiO.sub.2 region and adjacent to said interface of said SiO.sub.2 and Si regions;
said second impurity concentration representing a general impurity concentration of a second one of said domains located in said Si region and adjacent to said interface of said SiO.sub.2 and Si regions;
(b) forming diffusion equations at said respective mesh points in such a way that said doped impurity piles up into said first one of said domains located in said SiO.sub.2 region;
and
(c) solving said diffusion equations to derive a distribution of said doped impurity in said simulated zone.

7 more elements

A simulation method of diffusion of a doped impurity, comprising the steps of:

(a) configuring a mesh having mesh points on a simulated zone including a SiO.sub.2 region and a Si region contacted therewith, thereby partitioning said simulated zone into domains;
a first one of said mesh points being located in a SiO.sub.2 region;
a second one of said mesh points being located in a Si region;
a third one of said mesh points being located at an initial interface of said SiO.sub.2 and Si regions;
said third one of said mesh points serving as a double mesh point having first and second impurity concentrations;
said first impurity concentration representing a general impurity concentration of a first one of said domains located in said SiO.sub.2 region and adjacent to said initial interface of said SiO.sub.2 and Si region;
said second impurity concentration representing a general impurity concentration of a second one of said domains located in said Si region and adjacent to said initial interface of said SiO.sub.2 and Si regions;
(b) setting concentrations of said domains of said simulated zone as pre-oxidation values;
(c) calculating a growth of said SiO.sub.2 region in a given oxidizing atmosphere during a specific period, thereby finding a post-oxidation position of said initial interface of said SiO.sub.2 and Si regions and a post-oxidation profile of said SiO.sub.2 region;
said initial interface of said SiO.sub.2 and Si regions located at said post-oxidation position thus found being defined as a post-oxidation interface of said SiO.sub.2 and Si regions;
a part of said Si region sandwiched by said initial interface of said SiO.sub.2 and Si regions and said post-oxidation interface thereof being defined as a transition region;
(d) reconfiguring said mesh points and said domains to define a first post-oxidation mesh point located at said post-oxidation interface of said SiO.sub.2 and Si regions, a first post-oxidation domain located in said transition region and adjacent to said post-oxidation interface of said SiO.sub.2 and Si regions, and a second post-oxidation domain located in said Si region and adjacent to said post-oxidation interface of said SiO.sub.2 and Si regions;
said first post-oxidation mesh point serving as a double mesh point having third and fourth impurity concentrations;
said third impurity concentration representing a general impurity concentration of said first post-oxidation domain;
said fourth impurity concentration representing a general impurity concentration of said second post-oxidation domain;
(e) forming diffusion equations at said respective reconfigured mesh points in such a way that said doped impurity piles up from said first one of said domains located in said SiO.sub.2 region and adjacent to said initial interface of said SiO.sub.2 and Si regions into said first post-oxidation domain located in said transition region and adjacent to said post-oxidation interface of said SiO.sub.2 and Si regions;
(f) solving said diffusion equations to derive a distribution of said doped impurity at said respective reconfigured mesh points in said simulated zone;
and
(g) converting said transition region to SiO.sub.2 after said step (f).

16 more elements

A computer implemented method of simulating diffusion of a doped impurity, comprising the steps of:

(a) configuring in a computer a mesh having mesh points on a simulated zone including a SiO.sub.2 region and a Si region contacted therewith, thereby partitioning said simulated zone into domains;
a first one of said mesh points being located in a SiO.sub.2 region;
a second one of said mesh points being located in a Si region;
a third one of said mesh points being located at an interface of said SiO.sub.2 and Si regions;
said third one of said mesh points serving as a double mesh point having first and second impurity concentrations;
said first impurity concentration representing a general impurity concentration of a first one of said domains located in said SiO.sub.2 region and adjacent to said interface of said SiO.sub.2 and Si regions;
said second impurity concentration representing a general impurity concentration of a second one of said domains located in said Si region and adjacent to said interface of said SiO.sub.2 and Si region;
(b) forming diffusion equations at said respective mesh points in such a way that said doped impurity piles up into said first one of said domains located in said SiO.sub.2 ;
and
(c) solving said diffusion equations using the computer to derive a distribution of said doped impurity in said simulated zone.