Induced transition from Schottky to ohmic contact in In/n-type Si owing to (NH4)2Sx treatment

Indium metal is deposited on n-type Si (n-Si) samples with/without (NH4)(2)S-x treatment in order to experimentally study the mechanism for the transition from Schottky to ohmic contact. Indium metal that is deposited on a n-Si sample that is subject to (NH4)(2)S-x treatment shows ohmic behavior but indium metal that is deposited on a n-Si sample that is not subject to (NH4)(2)S-x treatment exhibits Schottky behavior. Using the transmission line method, the specific contact resistance of the In/(NH4)(2)S-x treated n-Si structure is calculated to be 283.3 m omega cm(2). Experimental identification confirms that the transformation to conduction behavior occurs because of the combined effect of broken Si-O bonds (i.e., the removal of the native oxide) and the formation of Si-S-x(2-) bonds at the Si surface, which results in a transition from upward to downward surface band bending for n-Si.

Automated summary

Experimental results show that indium metal exhibits ohmic behavior when it is deposited on n-Si samples that have been treated with (NH4)2S-x, while it exhibits Schottky behavior on untreated n-Si samples. This transition is attributed to the removal of the native oxide and the formation of Si-S-x^2- bonds on the Si surface, which cause a change in the surface band bending for n-Si.