Abstract: A dopant film contains an organic binder, an inorganic binder and a compound of an impurity element for diffusion. Both surfaces of the dopant film are coated with adhesive. Releasable sheets sandwich the dopant film. The dopant film permits automated alternate stacking with semiconductor wafers, providing an advantage of labor saving. When the alternate stacking is automated, it will become hard for the wafer breakage to occur, sharply decreasing the rate of breakage. Furthermore, since the adhesion of a semiconductor wafer improves, the variation in the diffusion depth will decrease.

Abstract: A dopant film contains an organic binder, an inorganic binder and a compound of an impurity element for diffusion. Both surfaces of the dopant film are coated with adhesive. Releasable sheets sandwich the dopant film. The dopant film permits automated alternate stacking with semiconductor wafers, providing an advantage of labor saving. When the alternate stacking is automated, it will become hard for the wafer breakage to occur, sharply decreasing the rate of breakage. Furthermore, since the adhesion of a semiconductor wafer improves, the variation in the diffusion depth will decrease. The semiconductor wafer manufacturing method includes the steps of impurity diffusion into both surfaces, dividing the wafer into two wafers in the direction of thickness, and polishing to a mirror surface each divided wafer opposite to the surface on which the impurity diffusion layer is formed. The material loss per wafer is reduced more than the conventional method due to the slicing into two wafers.

Abstract: An electrically-insulated type semiconductor device to be resin-moulded has a rear surface which can be set in direct contact with a heat radiation section and a front surface opposite to the rear surface. This semiconductor device includes a metal lead frame having a tip end portion sandwiched between the resin rear surface and resin front surface and a mounting portion on which a semiconductor chip is mounted, and frame supporting holes formed to penetrate from the resin front surface to the mounting portion of the lead frame. The frame supporting holes are formed by supporting pins for positioning the mounting portion of the lead frame. The frame supporting holes are formed only in the resin front surface, and the lead frame is formed in such a shape that a thickness of resin mould existing between the resin rear surface and the tip end portion of the lead frame is set to be larger than a thickness of resin mould existing between the resin rear surface and the mounting portion of the lead frame.