JPS6439745A - Manufacture of semiconductor substrate for integrated circuit device - Google Patents

Abstract

PURPOSE:To eliminate the wasteful use of a single crystalline silicon material and to save the material cost of a semiconductor substrate by digging a second groove from the opposite face to the face of a silicon substrate in which polycrystalline silicon is grown in the step of cutting the second groove to separate dielectrically the silicon substrate from a partial region. CONSTITUTION:A first groove 2 is dug in depth of approx. 150mum by anisotropically etching on one side face of a silicon substrate 1 to surround a range of a partial region. Then, the substrate 1 including the groove face is so covered on one whole face relatively thick to approx. 2mum by a steam oxidizing method as a dielectric film 3. Then, a polycrystalline silicon 4 is grown in thickness of 300-400mum on the whole film 3. Then, a second groove 5 is dug in depth of approx. 50mum to arrive at the film 3 by anisotropically etching at a position corresponding to the first groove 2 from the other side face of a semiconductor substrate. Thus, since the substrate 1 is separated dielectrically to a plurality of partial regions 6, an integrated circuit element may be formed. Thus, considerable part of the silicon substrate is not necessarily removed by polishing to save material cost.