Influence of Ta/sub 2/O/sub 5/ crystallization on the performance of capacitors for high-density DRAMs

The capacitance needed for the long refresh time of high-density DRAMs can be obtained by using a Ta/sub 2/O/sub 5/ capacitor. We found that the electrical characteristics of this capacitor are strongly related to the crystallization of Ta/sub 2/O/sub 5/ thin films. Accordingly, we found that a Ta/sub 2/O/sub 5/ crystal with a low intensity ratio (I/sub 200//I/sub 001/) surprisingly improves the electrical characteristics of the Ta/sub 2/O/sub 5/ capacitor. Our technique for controlling grain growth in the Ta/sub 2/O/sub 5/ film formation improves the electrical characteristics of a Ta/sub 2/O/sub 5/ capacitor considerably.