Line-Shaped Electron Beam System and Soi Films Prepared by The System

Abstract

ABSTRACTThe line-shaped electron beam annealing system which generates an electron beam of a length of 4 cm and a width af less than 100 um with a high energy density exceeding well over 100 kW/cm2 was developed for the first time with a purpose of SOI processing as its primary application. An pccelaration voltage of up to 20 kV can be used in this system. Seeded single crystalline islands with areas several mm long and 30 to 100 um in width were obtained by a single scan of the electron beam. The electron beam is generated in a pulsed way in the system due to the power restriction of the power supplies. An area of 4×5 cm2 was processed by a single scan of an electron beam at a sample speed of 530 cm/sec and a beam duration of 9.5 msec. The scanning area for one scan is determined by the beam length and the duration of the beam and sample speed.The present system could give single crystalline silicon films without any grain boundaries. The electron mobility of the electron beam recrystallized films, obtained from FETs made as a vehicle to test the electrical properties of the films, was comparable to that of the bulk silicon. A very rapid migration of silicon atoms in solid polycrystalline silicon films, which is controllable by process parameters, was also found with a migration speed of the order of 1 m/sec in a capped structure. The present electron beam system is useful in studying basic mechanisms of crystal growth in thin films. The system can have a very high throughput, a desirable feature in semiconductor industry. The present system can also be used to study the rapid thermal treatment of materials other than semiconductors including rapidly solidified materials.