Title :
Highly reliable, high-C DRAM storage capacitors with CVD TA/sub 2/O/sub 5/ films on rugged polysilicon
Author :
Lo, G.Q. ; Kwong, Dim-Lee ; Fazan, Pierre C. ; Mathews, V.K. ; Sandler, Nathan
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA
fDate :
5/1/1993 12:00:00 AM
Abstract :
The authors report on a highly reliable stacked storage capacitor with ultrahigh capacitance using rapid-thermal-annealed low-pressure chemical vapor deposited (LPCVD) Ta/sub 2/O/sub 5/ films ( approximately 100 AA) deposited on NH/sub 3/-nitrided rugged poly-Si electrodes. Capacitances as high as 20.4 fF/ mu /sup 2/ (corresponding to the thinnest t/sub ox.eff/ (16.9 AA) ever reported using LPCVD-Ta/sub 2/O/sub 5/ and poly-Si technologies) have been achieved with excellent leakage current and time-dependent dielectric breakdown (TDDB) characteristics. Extensive electrical characterization over a wide temperature range ( approximately 25-300 degrees C) shows that Ta/sub 2/O/sub 5/ films on rugged poly-Si electrodes have a better temperature stability in dielectric leakage and breakdown compared to the films on smooth poly-Si electrodes.<>
Keywords :
DRAM chips; capacitance; chemical vapour deposition; electric breakdown of solids; leakage currents; metal-insulator-semiconductor devices; rapid thermal processing; silicon; tantalum compounds; titanium compounds; 16.9 AA; 25 to 300 degC; DRAM storage capacitors; NH/sub 3/ nitridation; RTA LPCVD; Si; TiN-Ta/sub 2/O/sub 5/-Si; dielectric leakage; electrical characterization; highly reliable stacked storage capacitor; leakage current; rugged polysilicon; temperature stability; time-dependent dielectric breakdown; ultrahigh capacitance; Associate members; Capacitance; Capacitors; Dielectric breakdown; Electrodes; Leakage current; Random access memory; Stability; Temperature distribution; Tin;
Journal_Title :
Electron Device Letters, IEEE
