| 摘要 |
PURPOSE:To prevent decrease in internal defect density and also prevent occurrence of fine defect on an epitaxially grown layer, in a process of manufacturing of a bipolar device, by forming an embedded layer in a substrate crystal and providing it with 2-step heat-treatment process. CONSTITUTION:On a substrate on which a bipolar device is prepared, a hole is provided on an oxide coating 3 and an embedded layer 4 is formed in nitrogen atmosphere containing oxygen. And then, this substrate is provided with heat treatment at a temperature between 650 deg.C and 1,100 deg.C in dry oxygen, and an internal defect producing nucleus 7 is formed. And then, it is again heat-treated at a high temperature between 1,100 deg.C and 1,200 deg.C in wet-type or dry-type oxygen or inert gas, and the nucleus 7 is made to grow to a swirl-like internal defect. After the oxide coating 3 was removed, an epitaxial layer 5 is made to grow. As it is possible, by doing so, to prevent diminishing of internal defect which contributes to intrinsic gettering effect, it is possible to prevent the epitaxial layer 5 from occurrence of fine defect and to improve production recovery of the device. |
