The diffusion of Zn into dislocation-rich monocrystals was investigated by means of spreading resistance analysis (table 93). In order to carry out short-term isothermal annealing, a special technique was used which exploited the volatility of Zn at high temperatures. This permitted the progressive incorporation of Zn to be monitored in detail in the early stages of diffusion. By assuming the operation of the kick-out mechanism, effective diffusivities and interstitial-substitutional exchange rates were deduced from the temporal development of penetration profiles at temperature ranging from 1143 to 1481K. Deviations from the theoretical predictions were frequently observed, and could be accounted for by a deep trapping of Zn which was probably caused by dislocations. The fitting of computer-simulated profiles to the data furnished volume averages of the trap concentrations and trapping rates.

H.Bracht, N.A.Stolwijk, I.Yonenaga, H.Mehrer: Physica Status Solidi A, 1993, 137[2], 499-514

 

 

 

Table 93

Penetration Rate of Zn into Dislocation-Rich Si

 

T (C)

D (cm2/s)

870

4.0 x 10-9

942

1.6 x 10-8

1021

4.4 x 10-8

1115

1.3 x 10-7

1208

3.1 x 10-7