Investigation into the correct statistical distribution for oxide breakdown over oxide thickness range

2005 ◽  
Vol 45 (5-6) ◽  
pp. 973-977 ◽  
Author(s):  
James Prendergast ◽  
Eoin O’Driscoll ◽  
Ed Mullen
2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000116-000121
Author(s):  
K. Grella ◽  
S. Dreiner ◽  
H. Vogt ◽  
U. Paschen

Standard Bulk-CMOS-technology targets use-temperatures of not more than 175 °C. With Silicon-on-Insulator-technologies (SOI), digital and analog circuitry is possible up to 250 °C and even more, but performance and reliability are strongly affected at these high temperatures. One of the main critical factors is the gate oxide quality and its reliability. In this paper, we present a study of gate oxide capacitor time-dependent dielectric breakdown (TDDB) measurements at temperatures up to 350 °C. The experiments were carried out on gate oxide capacitor structures which were realized in the Fraunhofer 1.0 μm SOI-CMOS process. This technology is based on 200 mm wafers and features, among others, three layers of tungsten metallization with excellent reliability concerning electromigration, voltage independent capacitors, high resistance resistors, and single-poly-EEPROM cells. The gate oxide thickness is 40 nm. Using the data of the TDDB-measurements, the behavior of field and temperature acceleration parameters at temperatures up to 350 °C was evaluated. For a more detailed investigation, the current evolution in time was also studied. An analysis of the oxide breakdown conditions, in particular the field and temperature dependence of the charge to breakdown and the current just before breakdown, completes the study. The presented data provide important information about accelerated oxide reliability testing beyond 250 °C, and make it possible to quickly evaluate the reliability of high temperature CMOS-technologies at use-temperature.


2013 ◽  
Vol 10 (4) ◽  
pp. 150-154 ◽  
Author(s):  
K. Grella ◽  
S. Dreiner ◽  
H. Vogt ◽  
U. Paschen

It is difficult to use standard bulk-CMOS-technology at temperatures higher than 175°C due to high pn-leakage currents. Silicon-on-insulator-technologies (SOI), on the other hand, are usable up to 250°C and even higher, because leakage currents can be reduced by two to three orders of magnitude. Nevertheless, performance and reliability of SOI devices are strongly affected at these high temperatures. One of the main critical factors is the gate oxide quality and its reliability. In this paper, we present a study of gate oxide capacitor time-dependent dielectric breakdown (TDDB) measurements at temperatures up to 350°C. The experiments were carried out on gate oxide capacitor structures realized in the Fraunhofer 1.0 μm SOI-CMOS process. The gate oxide thickness is 40 nm. Using the data of the TDDB measurements, the behavior of field and temperature acceleration parameters at temperatures up to 350°C was evaluated. For a more detailed investigation, the evolution of the current in time was also studied. An analysis of the oxide breakdown conditions, in particular the field and temperature dependence of the charge to breakdown and the current just before breakdown, completes the study. The presented data provide important information about accelerated oxide reliability testing beyond 250°C, and make it possible to quickly evaluate the reliability of high temperature CMOS technologies at operation temperature.


1992 ◽  
Vol 262 ◽  
Author(s):  
Worth B. Henley ◽  
Lubek Jastrzebski ◽  
Nadim F. Haddad

ABSTRACTThe effect of iron contamination in silicon on the properties of thermally grown thin oxides is studied through electrical modelling and experimental MOSDOT testing. Iron concentration is measured using a surface photovoltage / diffusion length technique. Failure mechanisms related to iron contamination are proposed. Contamination limits for various gate oxide thicknesses are defined. Experimental results show that reduction of oxide thickness from 20nm to lOnm requires a reduction in iron conntamination by 100 times.


2013 ◽  
Vol 740-742 ◽  
pp. 745-748 ◽  
Author(s):  
J. Sameshima ◽  
Osamu Ishiyama ◽  
Atsushi Shimozato ◽  
K. Tamura ◽  
H. Oshima ◽  
...  

Time-dependent dielectric breakdown (TDDB) measurement of MOS capacitors on an n-type 4 ° off-axis 4H-SiC(0001) wafer free from step-bunching showed specific breakdown in the Weibull distribution plots. By observing the as-grown SiC-epi wafer surface, two kinds of epitaxial surface defect, Trapezoid-shape and Bar-shape defects, were confirmed with confocal microscope. Charge to breakdown (Qbd) of MOS capacitors including an upstream line of these defects is almost the same value as that of a Wear-out breakdown region. On the other hand, the gate oxide breakdown of MOS capacitors occurred at a downstream line. It has revealed that specific part of these defects causes degradation of oxide reliability. Cross-sectional TEM images of MOS structure show that gate oxide thickness of MOS capacitor is non-uniform on the downstream line. Moreover, AFM observation of as-grown and oxidized SiC-epitaxial surfaces indicated that surface roughness of downstream line becomes 3-4 times larger than the as-grown one by oxidation process.


Author(s):  
Osvaldo Gasparri ◽  
Mirko Bernardoni ◽  
Paolo Del Croce ◽  
Andrea Baschirotto

Abstract OTP (One Time Programmable) memory in power technology enables electrical performance optimization together with area occupation reduction. In this paper, the aspects relative to the oxide breakdown (which is the key mechanism for memory programmability) are studied and applied to the development of an antifuse OTP cell in a 350 nm-CMOS power technology. The physical analysis of the degradation phases of an oxide layer is presented together with the physical models, exploited to foresee the device time-to-breakdown depending on applied voltage, oxide thickness etc. The achieved results are used in the development and reliable implementation of OTP cells in the target 350 nm-CMOS node.


1997 ◽  
Vol 473 ◽  
Author(s):  
Heng-Chih Lin ◽  
Edwin C. Kan ◽  
Toshiaki Yamanaka ◽  
Simon J. Fang ◽  
Kwame N. Eason ◽  
...  

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.


2002 ◽  
Vol 716 ◽  
Author(s):  
D. Jacques ◽  
S. Petitdidier ◽  
J.L. Regolini ◽  
K. Barla

AbstractOxide/Nitride dielectric stack is widely used as the standard dielectric for DRAM capacitors. The influence of the chemical cleaning prior to the stack formation has been studied in this work. As a result, morphological data such as stack surface roughness (Atomic Force Microscopy) and silicon nitride (SiN) incubation time for growth are comparable for all the studied cases on <Si>. However, Tof-SIMS exhibits different oxygen content at the Si/stack interface following the different chemical treatments. Electrical measurements show comparable C-V and I-V results, for the same Equivalent Oxide Thickness (same capacitance at strong accumulation i.e.-3V) while the different studied interfaces bring different interface states density with lower values for higher interfacial oxygen content. For DRAM applications, a clear improvement in electrical characteristics is obtained under low interfacial oxygen content conditions. Results are compared in embedded-DRAM cells for which we developed an industrially compatible dielectric deposition sequence to obtain minimum leakage current with maximum specific capacitance and no particular linking constraints.


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