| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for forming a good strap contact. SOLUTION: On the surface of a Si substrate 1 having word lines 5 formed via an insulating film 2c to partly overlap a capacitor charge storage node 4, a SiN film 7b is formed and then patterned, thus leaving the SiN film 7b only on the lateral sides of the word lines 5. After that, a source region 8 and a drain region are formed. Then, a SiO2 film 6b, a SiN film 7c and a BPSG film 7d are sequentially deposited on the surface of the Si substrate 1, and these films between the word lines 5 are removed by RYE, thereby opening a contact with the capacitor charge storage node 4. At this point, the SiN film 7c remains on the lateral sides of a portion where the source region 8 is to be formed on the capacitor charge storage node 4. On the surface thereof, a patterned polysilicon film 9a is formed and a strap contact 9 is formed. Thus, the polysilicon film 9a and the semiconductor substrate do not directly contact each other, and a vertical parasitic MOS is prevented from being generated. |
