US 6,486,682 B1Granted

Determination of dielectric constants of thin dielectric materials in a MOS (metal oxide semiconductor) stack

AssigneeAdvanced Micro Devices, Inc.

InventorsZhigang Wang, Nian Yang, Tien-Chun Yang

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Abstract

First and second dielectric constants, e1 and e2 respectively, for first and second dielectric materials forming a MOS (metal oxide semiconductor) stack are determined. First and second test MOS stacks having first and second total effective oxide thickness, EOTA and EOTB, respectively, are formed. The first and second test MOS stacks include first and second interfacial structures comprised of the second dielectric material with first and second thickness, T2A and T1A, respectively. In addition, the first and second test MOS stacks include first and second high-K structures comprised of the first dielectric material with first and second thickness, T2B and T1B, respectively. The thickness parameters EOTA, T1A, T2A, EOTB, T1B, and T2B of the test MOS stacks are measured. The dielectric constants, e1 and e2, are then determined depending on relations between values of EOTA, T1A, and T2A, and between values of EOTB, T1B, and T2B.

Claims24

Dependent claims

A method for determining a first dielectric constant, e1, for a first dielectric material and a second dielectric constant, e2, for a second dielectric material forming a MOS (metal oxide semiconductor) stack, the method including the steps of:

A. forming a first test MOS (metal oxide semiconductor) stack having a first total effective oxide thickness, EOTA, and being comprised of:
a first interfacial structure comprised of said second dielectric material having said second dielectric constant, e2, and having a first interfacial thickness T2A, wherein said first interfacial structure is disposed on a semiconductor substrate;
and
a first high-K structure comprised of said first dielectric material having said first dielectric constant, e1, and having a first high-K thickness, T1A, wherein said first high-K structure is disposed between said first interfacial structure and a first conductive structure;
B. forming a second test MOS (metal oxide semiconductor) stack having a second total effective oxide thickness, EOTB, and being comprised of:
a second interfacial structure comprised of said second dielectric material having said second dielectric constant, e2, and having a second interfacial thickness T2B, wherein said second interfacial structure is disposed on said semiconductor substrate;
and
a second high-K structure comprised of said first dielectric material having said first dielectric constant, e1, and having a second high-K thickness T1B, wherein said second high-K structure is disposed between said second interfacial structure and a second conductive structure;
C. measuring said first total effective oxide thickness, EOTA, of said first test MOS stack and measuring said second total effective oxide thickness, EOTB, of said second test MOS stack;
D. measuring said first interfacial thickness, T2A, of said first interfacial structure and measuring said first high-K thickness, T1A, of said first high-K structure;
E. measuring said second interfacial thickness, T2B, of said second interfacial structure and measuring said second high-K thickness, T1B, of said second high-K structure;
and
F. determining said first dielectric constant, e1, and said second dielectric constant, e2, depending on relations between values of EOTA, T1A, and T2A, and between values of EOTB, T1B, and T2B.

10 more elements

A system for determining a first dielectric constant, e1, for a first dielectric material and a second dielectric constant, e2, for a second dielectric material forming a MOS (metal oxide semiconductor) stack, the system comprising:

a first test MOS (metal oxide semiconductor) stack having a first total effective oxide thickness, EOTA, and being comprised of:
a first interfacial structure comprised of said second dielectric material having said second dielectric constant, e2, and having a first interfacial thickness T2A, wherein said first interfacial structure is disposed on a semiconductor substrate;
and
a first high-K structure comprised of said first dielectric material having said first dielectric constant, e1, and having a first high-K thickness, T1A, wherein said first high-K structure is disposed between said first interfacial structure and a first conductive structure;
a second test MOS (metal oxide semiconductor) stack having a second total effective oxide thickness, EOTB, and being comprised of:
a second interfacial structure comprised of said second dielectric material having said second dielectric constant, e2, and having a second interfacial thickness T2B, wherein said second interfacial structure is disposed on said semiconductor substrate;
and
a second high-K structure comprised of said first dielectric material having said first dielectric constant, e1, and having a second high-K thickness T1B, wherein said second high-K structure is disposed between said second interfacial structure and a second conductive structure;
means for measuring said first total effective oxide thickness, EOTA, of said first test MOS stack and measuring said second total effective oxide thickness, EOTB, of said second test MOS stack;
means for measuring said first interfacial thickness, T2A, of said first interfacial structure and measuring said first high-K thickness, T1A, of said first high-K structure;
and
means for measuring said second interfacial thickness, T2B, of said second interfacial structure and measuring said second high-K thickness, T1B, of said second high-K structure;
wherein said first dielectric constant, e1, and said second dielectric constant, e2, are determined from relations between values of EOTA, T1A, and T2A, and between values of EOTB, T1B, and T2B.

10 more elements

Dependencies are inferred from the claim text.