SOI Structures Formed Using Line-Source Electron Beam Recrystallization

Abstract

AbstractRecrystallization of silicon-on-insulator (SOI) films using a line-source electron beam is described. This unique heat source can continuously emit several kilowatts of - 5 keV electrons into a beam 150 mm in length and - 2.5 mm in width, an exposure area which allows processing of 100 mm substrates in a single pass. An attractive aspect of this beam is the ability to control the beam profile, which in turn allows one to influence the thermal gradients present during recrystallization. Using a tightly focussed beam to recrystallize the SOI layer results in a film whose physical properties are generally attributed to films grown with a high thermal gradient at the solidifying liquid-solid interface (highly branched subboundaries with a maximum spacing of - 20 microns and several degrees of angular mismatch.) By reducing the gradient at the growth interface it is possible to achieve unbranched sub-boundaries with over 70 micron spacing and less than 0.5 degrees of out-of-plane tilt misalignment.