Title :
Influence of Ta2O5 crystallization on the performance of capacitors for high-density DRAMs
Author :
Furukawa, R. ; Kanda, N. ; Yamamoto, H. ; Yoshida, T. ; Yamagami, N. ; Uemura, T. ; Honma, T. ; Kanai, Masashi ; Kunitomo, M. ; Takahashi, M. ; Uchiyama, H. ; Ohji, Y.
Author_Institution :
Device Dev. Center, Hitachi Ltd., Tokyo, Japan
Abstract :
The capacitance needed for the long refresh time of high-density DRAMs can be obtained by using a Ta2O5 capacitor. We found that the electrical characteristics of this capacitor are strongly related to the crystallization of Ta2O5 thin films. Accordingly, we found that a Ta2O5 crystal with a low intensity ratio (I200/I001) surprisingly improves the electrical characteristics of the Ta2 O5 capacitor. Our technique for controlling grain growth in the Ta2O5 film formation improves the electrical characteristics of a Ta2O5 capacitor considerably
Keywords :
CVD coatings; DRAM chips; capacitance; crystallisation; dielectric thin films; electric breakdown; grain growth; leakage currents; rapid thermal annealing; recrystallisation annealing; tantalum compounds; thin film capacitors; LPCVD films; TDDB lifetime; Ta2O5; Ta2O5 capacitor; Ta2O5 crystallization; Ta2O5 thin films; XRD profile; capacitance; capacitor performance; electrical characteristics; grain growth control; high-density DRAMs; leakage current; low intensity ratio; rapid thermal oxidation; refresh time; Capacitance; Capacitors; Crystallization; Dielectric thin films; Electrodes; Leakage current; Material storage; Random access memory; Semiconductor thin films; Transistors;
Conference_Titel :
Semiconductor Manufacturing Conference Proceedings, 1999 IEEE International Symposium on
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-7803-5403-6
DOI :
10.1109/ISSM.1999.808783
