Samples were implanted with 120keV S+ ions to doses of between 3 x 1013 and 1015/cm2 (table 19). They were capped with an 80nm-thick film of amorphous hydrogenated Si, into which As was doped to a concentration of 2 x 1020/cm3. The samples were then annealed in Ar gas (850 to 1000C, 0.25h). It was found that the diffusivity of S (table 20) could be described by the expression:

D = Dm[KQ2/(1 + KQ2)]

where K was a constant, Q was the implantation dose, and Dm was the diffusivity of a mobile complex.

M.Sakaguchi, K.Yokota, A.Shiomi, K.Hirai, H.Takano, M.Kumagai: Japanese Journal of Applied Physics, 1996, 35[1-8], 4203-8

 

 

 

Table 19

Diffusivity of Implanted S in GaAs

 

120keV S+ (/cm2)

Temperature (C)

D (cm2/s)

1 x 1015

1000

1.4 x 10-12

1 x 1015

950

9.6 x 10-13

1 x 1015

900

7.1 x 10-13

1 x 1015

850

5.4 x 10-13

5 x 1014

1000

9.9 x 10-13

5 x 1014

950

7.9 x 10-13

5 x 1014

900

4.9 x 10-13

5 x 1014

850

3.0 x 10-13

1 x 1014

1000

5.0 x 10-13

1 x 1014

950

3.4 x 10-13

1 x 1014

900

1.3 x 10-13

5 x 1013

1000

2.6 x 10-13

5 x 1013

950

1.4 x 10-13

 

 

 

 

Table 20

Diffusion Parameters for Implanted S in GaAs

 

Dose (/cm2)

Do (cm2/s)

E (eV)

1 x 1015

2.0 x 10-9

0.8

5 x 1014

9.0 x 10-9

1.0

1 x 1014

4.2 x 10-7

1.5

5 x 1013

5.5 x 10-7

1.6