| 摘要 |
PURPOSE:To form a semiconductor island region with a low collector resistance by a method wherein a semiconductor layer is formed on a sapphire substrate in which an ion injected impurities and the ion injected impurities are diffused throughout semiconductor layers. CONSTITUTION:A P or As is ion injected on the sapphire substrate 20 to form a region 21 containing n type impurities. Next thereto, an n type high resistance S film 22 is formed to coat an SiO2 film 23. Following the above, an isolating groove 25 is formed by making a positive type resist 24 as a mask, the organic silicon alcohol solution containing P or As is coated thereupon to form a silicon film 26. Then, a heat treatment is made at 900 deg.C-1,100 deg.C, the ion injected impurities on the sapphire substrate surface is diffused in the Si film 22 to form an n<+> type region 29. Hereby the transistor with a low collector series resistance can be obtained by the insulator isolation method and the number of processes can be reduced. |
