The diffusion of Sn in intrinsic Ge was studied, at temperatures ranging from 555 to 930C, by means of secondary ion mass spectrometry. The Sn was in-diffused, under vacuum conditions, from both the gas phase and from thin films. In both cases, the pure metal was used as a source of Sn. Within the above temperature range, the diffusivity of Sn as a function of temperature (table 3) could be expressed by:

D(cm2/s) = 840 exp[-3.26(eV)/kT]

On the basis of similarities between Sn diffusion and Ge self-diffusion, it was concluded that Sn in Ge diffused via a mono-vacancy mechanism.

M.Friesel, U.Södervall, W.Gust: Journal of Applied Physics, 1995, 78[9], 5351-5

 

 

 

Table 3

Diffusivity of Tin in Germanium

 

 

T (C)

 

Method

 

D (cm2/s)

 

 

930

 

gas phase

 

2.22 x 10-11

900

gas phase

8.92 x 10-12

875

gas phase

3.73 x 10-12

850

gas phase

1.89 x 10-12

825

gas phase

8.32 x 10-13

800

gas phase

4.28 x 10-13

775

gas phase

1.71 x 10-13

750

gas phase

6.92 x 10-14

725

gas phase

1.95 x 10-14

700

gas phase

1.33 x 10-14

650

gas phase

1.57 x 10-15

615

gas phase

2.72 x 10-16

555

gas phase

1.19 x 10-17

900

thin film

7.84 x 10-12

750

thin film

6.57 x 10-14

700

thin film

1.12 x 10-14