Characterization in Silicon Processing

E

UQ

—

a

(3.6)

σ

2v a

0

or

σ

E

CL

—

(3.7)

1 - ν a

0

In these equations, Ε is Young's modulus, ν is Poisson

s

ratio of the film, and a

Q

and

a

are the lattice constants of the unstrained and the strained material, respectively.

Equation 3.6 refers to the value of a perpendicular to the film plane, and Equation

3.7 refers to the case where a is the lattice constant in the plane of the film. The

technique, although accurate, is time-consuming and requires a good understanding

of the diffraction process and the equipment. Recently, specialized diffractometers,

such as a generalized focusing diffractometer, have been designed to determine the

strai ...