Abstract: An electric oven with a baking frame for placing an object to be broiled or baked on it, includes a base, a net, a support frame vertically fitted in one side of the base and having several grooves respectively in two vertical sides, a position frame, a piercing member and a motor. The base has a large recess with four circumferential edges provided with an insert hole in two opposite edges. The position frame vertically fixed in the other side of the base has several pairs of hang holes in an upper portion and a slot formed under each pair of the hang holes corresponds to the grooves of the support frame. After the pointed end of the piercing memer piercing an object is inserted in a shaft hole of the motor, the piercing member is slowly rotated so as to have the object broiled evenly on the oven.

Abstract: This ion implantation method reduces the observed levels of cross-contamination and reduces the level of variations in surface conductivity related to the provision of multiple ion implantations into a semiconductor wafer. Reduced levels of cross-contamination are obtained by purging the implantation chamber and then evacuating the implantation chamber before beginning an implantation process. This purge and evacuation cycle is believed to be particularly effective in reducing cross-contamination when two implantations are made consecutively into a wafer without removing the wafer from the implantation chamber or when successive wafers are transported into the ion implantation chamber and implantations are made into each successive wafer.