| 摘要 |
PURPOSE:To improve the characteristics and to microminiaturize a separating layer by forming impurity layers for channel stopper on the entire side and bottom of a deep groove for separating an element of a semiconductor substrate. CONSTITUTION:An SiO2 film 20 and an Si3N4 film 21 are superposed on an n type Si substrate 1, a CVD SiO2 mask is coated, and a deep groove 23 is formed by an RIE. P is thermally diffused to form an n type layer 16, an SiO2 film 12a is coated on the inner surface of the groove, a polysilicon film 13 is accumulated, etched back to remain only in the groove. The film 21 is removed, a new Si3N4 film 24 is coated, a CVD SiO2 film 25 is superposed, partly superposed with the groove 23 to open a window 25a. The second deep groove 26 is formed by an RIE, and the mask 25 is removed. B is thermally diffused to form a p type layer 15 on the side and the bottom of the groove 26, an SiO2 film 12b is coated, and a polysilicon film 13 is filled similarly to the previous time. Then, the film 24 is removed, an SiO2 film 14 is coated to complete a separating layer 2. A p type well 5 is then formed, and a device is formed by a normal method. According to this configuration, no parasitic channel or leakage current occur, characteristics are improved, the separating layer can be microminiaturized, and the devices can be highly integrated. |
