Patent ID: 6855580
Filing Date: 2005-02-15
Classification: H01L

Abstract:
1. A method of manufacturing a complementary semiconductor device having at least an n-channel thin film transistor and a p-channel thin film transistor, comprising: forming a semiconductor film comprising amorphous silicon on an insulating surface; providing the semiconductor film with a metal containing material, wherein the metal is capable of promoting crystallization of amorphous silicon; heating the semiconductor film and the metal containing material in order to crystallize the semiconductor film; patterning the crystallized semiconductor film into at least first and second semiconductor islands, each including a channel formation region; forming a gate electrode over the first and second semiconductor islands with a gate insulating film interposed therebetween; introducing phosphorus into both of the first and second semiconductor islands by at least in part using the gate electrodes as masks, thereby at each of the first and second semiconductor islands forming a pair of lightly doped regions that are adjacent to the channel region and opposing each other with respect to the channel region and a pair of heavily doped regions each located on one side of the channel region and in direct contact with one of the lightly doped regions, wherein the heavily doped regions are doped at a first concentration and the lightly doped regions are doped at a second concentration smaller than the first concentration by a first difference amount; and introducing boron into only one of the first and second semiconductor islands by using at least in part the gate electrode as a mask to dope the heavily doped regions at a third concentration and the lightly doped regions at a fourth concentration larger than the second concentration, the third concentration being larger than the fourth concentration by a second difference amount that is smaller than the first difference amount; irradiating the first and second semiconductor islands with a laser light after introducing said phosphorus and introducing said boron; and heating the first and second semiconductor islands after the irradiating with the laser light in order to getter the metal residing therein.