| 摘要 |
PURPOSE:To easily obtain a deep insular region, by forming an N type trapezoid by accumulating N type epitaxial layer on P type trapezoid on P type Si surface and exposing the sole of convex part of P and N type by accumulating a dielectric layer and a poly Si layer and abrading the back side of the substrate. CONSTITUTION:The trapezoid 11 is formed by anithotropic etching the (100) face of P<-> type Si substrate 1, then by ion injection P<+> layer 12 is formed on the surface. Then, by covering with SiO2 13 and selectively opening to attain epitaxial growth, thus forming N layer on the opening 15 and poly Si layer 15' on film 13. Again anithotropic etching of eliminate all of layer 15' and a part of layer 15, N type trapezoid 16 is formed. N layer 17 and SiO2 18 are accumulated on the surface of trapezoid 16. Then by covering with poly Si 19 and abrading from the back surface of substrate 1 to expose the sole of trapezoid 11 and 16, P and N type insular region 11' and 16' are completed, separated by the dielectric layer. This structure enables controlling impurity concentration and thickness of insular regions 11' and 16' at a certain level. |
