Intrinsic As diffusion properties in relaxed Si1–xGex epilayers were determined. The properties were studied, as a function of x, for x = 0, 0.20, 0.35, 0.50, 0.65, 0.8 and 1 (table 9). The activation enthalpy was found to fall systematically from 3.8eV (x = 0) to 2.4eV (x = 1). A comparison with other impurity atom- and self-diffusion results, for Si, Ge and SiGe, showed that both interstitials and vacancies contributed to diffusion for x = 0 to 0.35, and that the vacancy mechanism dominated diffusion for x = 0.35 to 1.

Arsenic Diffusion in Relaxed Si1–xGex. P.Laitinen, I.Riihimäki, J.Räisänen, Isolde: Physical Review B, 2003, 68[15], 155209 (6pp)

 

Table 9

Arrhenius Parameters for As in Si1-xGex

 

Temperature Range (C)

x

E (eV)

Do (m2/s)

882-1120

0

3.81

4.3 x 10-4

882-1120

0.20

3.83

3.0 x 10-3

812-1050

0.35

3.68

2.3 x 10-3

750-1020

0.50

3.47

1.8 x 10-3

675-870

0.65

3.16

1.6 x 10-3

696-925

0.80

2.97

1.1 x 10-3

490-600

1.00

2.42

5.8 x 10-4