P. Gaworzewski et al., DOPANT ELECTRICAL-ACTIVITY OF SI AND SI1-XGEX MULTILAYER STRUCTURES DOPED WITH DELTA-LIKE BORON SPIKES AT DIFFERENT TEMPERATURES, Journal of applied physics, 75(12), 1994, pp. 7869-7875
Boron spikes within multilayer structures of Si and of Si1-xGex deposi
ted by means of molecular-beam epitaxy (MBE) at different temperatures
have been investigated by secondary-ion-mass spectrometry (SIMS), spr
eading resistance, and Hall-effect measurements. For a Ge amount of x
= 7% it is shown that segregation effects, electrical activity of B, s
teepness of B spikes, and solid solubility of B differ in Si and Si1-x
Gex at the same deposition temperatures. For Si1-xGex growth the. surf
ace segregation is significantly reduced in comparison to the growth o
f Si layers. Steeper B profiles can be obtained at same temperatures b
ut the amount of electrically inactive B is higher. Calculations of th
e charge-carrier distributions near the spikes have been performed usi
ng classical and quantum mechanical approaches to find out reasons for
deviations of the concentration profiles of B and of holes obtained f
rom SIMS and from spreading resistance measurements, respectively.