Title :
Long term reliability of SiO2/SiN/SiO2 thin layer insulator formed in 9 μm deep trench on high boron concentrated silicon
Author :
Nishimura, Aki ; Murata, Shinya ; Kuroda, Shigeru ; Enomoto, Osaomi ; Kitegawa, H. ; Hasegawa, Shinichi
Author_Institution :
Texas Instrum. Japan Ltd., Ibaraki, Japan
Abstract :
The SiO2/SiN/SiO2 (ONO) capacitor formed in the 9 μm-deep trench is investigated in terms of leakage current and long-term reliability. The leakage current and time-dependent dielectric breakdown (TDDB) characteristics are comparable for both planar and trench type ONO structures. Therefore the test results are not specific to trench structures only but are common characteristics of ONO films. Breakdown voltage of the ONO film is dependent on gate bias polarity and the ratio of bottom-oxide to top-oxide thicknesses. In general, the current is controlled by the exit-oxide thickness for electron current in the ONO film. The mean time to failure becomes longer as the nitride thickness increases. This characteristic is most prominent in the nitrogen annealed samples. The behavior of electric-field factor β was investigated for variations in nitride thickness. From these results it is concluded that nitride-dominant ONO film is better for long-term reliability
Keywords :
dielectric thin films; electric breakdown of solids; leakage currents; reliability; semiconductor-insulator boundaries; silicon compounds; ONO capacitor; Si:B; SiO2-SiN-SiO2-Si:B; electric-field factor; electron current; gate bias polarity; leakage current; long-term reliability; mean time to failure; nitride thickness; oxide thickness; thin layer insulator; time-dependent dielectric breakdown; trench structures; Annealing; Capacitors; Dielectric constant; Insulation; Leakage current; Nitrogen; Random access memory; Silicon compounds; Testing; Thickness measurement;
Conference_Titel :
Reliability Physics Symposium, 1989. 27th Annual Proceedings., International
Conference_Location :
Phoenix, AZ
DOI :
10.1109/RELPHY.1989.36338
