Manufacture of read only semiconductor memory device
Abstract
Abstract PURPOSE:To reduce the occupying area of a memory cell, by forming a contact hole in a self-aligning mode with respect to gate electrode structures. CONSTITUTION:At first, an insulating film 12, a polycrystalline silicon layer 13 and an insulating film 15 are sequentially formed on a semiconductor substrate 11. Impurity ions are implanted in a specified region 14 in correspondence with writing information. Then, the three-layer structure film 12, 13 and 15 on the substrate 11 are selectively etched away at the same time, and gate electrode structures 16A and 16B are formed. With the gate electrode structures as masks, reverse conducting type semiconductor regions 17 and 18 are formed. Thereafter, an insulating film 19 is formed on the entire surface. A contact hole 20 is formed by anisotropic etching in a self-aligning mode. Thereafter, a drain region 24, a source region 25, a contact pad 26, a wiring 29 and the like are formed by deposition of a polycrystalline silicon layer 21, implantation of impurities, etching and the like.
Inventors
- 👤 Shoji Ariizumi
- 👤 有泉 昇次
- 👤 Fujio Masuoka
- 👤 富士雄 舛岡
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.