Electrical properties of boron-doped p-SiGeC grown on n--Si substrate

Electrical properties of fully strained boron-doped Si0.90-yGe0.10Cy/n(-)-Si grown by low pressure chemical vapor deposition have been investigated as a function of carbon content (0.2%-1.5%), using the variable temperature (25-650 K) Hall-effect technique. The results of Hall-effect measurements show that the Si substrate and the SiGeC/Si interfacial layer affect significantly the electrical properties of the SiGeC epitaxial layer. Thus, a three-layer conducting model has been used to extract the carrier concentration and mobility of the SiGeC layer alone. At room temperature, the hole carrier concentration decreases from 6.8x10(17) to 2.4x10(17) cm(-3) and the mobility decreases from 488 to 348 cm(2)/V s as the carbon concentration increases from 0.2% to 1.5%. The boron activation energy increases from 20 to 50 meV as C increases from 0.2% to 1.5% with an increment of 23 meV per atomic % of C. (C) 2000 American Institute of Physics. [S0003-6951(00)01835-0].