Electrical properties of boron delta-layers in silicon

Abstract

726-731<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Electrical properties or MBE grown boron δ- layer in Si have been investigated in the temperature range 10-300 K and a comparative study with their uniform doping counterpart has been presented. Various boron doping levels from 1012-1014 <span style="font-size:14.0pt;line-height:115%;font-family: " times="" new="" roman";mso-fareast-font-family:hiddenhorzocr;color:black;mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">cm-2 in the δ- layer show that, with the fall of temperature from 300 to 50 K. Hall mobility first increases followed by a rapid decrease, and at temperature ≤50 K, it becomes almost constant. Higher doping level in the sample grossly lowers the value of Hall mobility but its variations with temperature are almost similar to each other. Existence of the dominant carrier scattering mechanism has also been reported. In all the samples, freeze-out of carriers have been clearly noticed below 100K. Existence of a Mott metal-non-metal transition in the sample has been observed at low temperature region when the doping <span style="font-size:14.0pt;line-height:115%;font-family: " times="" new="" roman";mso-fareast-font-family:hiddenhorzocr;color:black;mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">concentration exceeds a critical high value of 6×10-13 cm-2, and this has been found consistently with the other observations like zero activation energy and negative TCR. The value of minimal metallic conductance for the samples has also been reported.</span