Microcontact printing of indium metal using salt solution “ink”

Poly(dimethlysiloxane) stamps were made from Si masters fabricated using photolithography and anisotropic etching. GaCl3 and In(NO3)3 were microcontact printed onto Si substrates, creating arrays of micron size metal salt deposits. The In(NO3)3 deposits were further processed by annealing in an N2 :H2 (9:1) forming gas environment at 600 °C which converted the deposits into In metal. The ability to inexpensively pattern metal arrays on semiconductor surfaces has implications for ohmic contacts and, with additional processing, arrays of semiconductor crystallites for optoelectronic applications.