A Study on the Reliability and Stability of High Voltage 4H-SiC MOSFET Devices

2006 ◽  
Vol 527-529 ◽  
pp. 1313-1316 ◽  
Author(s):  
Sumi Krishnaswami ◽  
Sei Hyung Ryu ◽  
Bradley Heath ◽  
Anant K. Agarwal ◽  
John W. Palmour ◽  
...  

Gate oxide reliability measurements of 4H-SiC DMOSFETs were performed using the Time Dependent Dielectric Breakdown (TDDB) technique at 175°C. The oxide lifetime is then plotted as a function of the electric field. The results show the projected oxide lifetime to be > 100 years at an operating field of ~3 MV/cm. Device reliability of 2.0 kV DMOSFETs was studied by stressing the gate with a constant gate voltage of +15 V at a temperature of 175°C, and monitoring the forward I-V characteristics and threshold voltage for device stability. Our very first measurements show very little variation between the pre-stress and post-stress conditions up to 1000 hrs of operation at 175°C. In addition, forward on-current stressing of the MOSFETs show the devices to be stable up to 1000 hrs of operation.

2008 ◽  
Vol 600-603 ◽  
pp. 1131-1134 ◽  
Author(s):  
Kevin Matocha ◽  
Zachary Stum ◽  
Steve Arthur ◽  
Greg Dunne ◽  
Ljubisa Stevanovic

SiC vertical MOSFETs were fabricated and characterized to achieve a blocking voltage of 950 Volts and a specific on-resistance of 8.4 mW-cm2. Extrapolations of time-dependent dielectric breakdown measurements versus applied electric field indicate that the gate oxide mean-time to failure is approximately 105 hours at 250°C.


2012 ◽  
Vol 717-720 ◽  
pp. 1073-1076 ◽  
Author(s):  
Mrinal K. Das ◽  
Sarah K. Haney ◽  
Jim Richmond ◽  
Anthony Olmedo ◽  
Q. Jon Zhang ◽  
...  

Significant advancement has been made in the gate oxide reliability of SiC MOS devices to enable the commercial release of Cree’s Z-FET™ product. This paper discusses the key reliability results from Time-Dependent-Dielectric-Breakdown (TDDB) and High Temperature Gate Bias (HTGB) measurements that indicate that the SiC MOSFETs can demonstrate excellent lifetime and stable operation in the field.


2007 ◽  
Vol 46 (No. 28) ◽  
pp. L691-L692 ◽  
Author(s):  
Takashi Miyakawa ◽  
Tsutomu Ichiki ◽  
Junichi Mitsuhashi ◽  
Kazutoshi Miyamoto ◽  
Tetsuo Tada ◽  
...  

2019 ◽  
Vol 963 ◽  
pp. 782-787
Author(s):  
Kevin Matocha ◽  
In Hwan Ji ◽  
Sauvik Chowdhury

The reliability and ruggedness of Monolith/Littelfuse planar SiC MOSFETs have been evaluated using constant voltage time-dependent dielectric breakdown for gate oxide wearout predictions, showing estimated > 100 year life at VGS=+25V and T=175C. Using extended time high-temperature gate bias, we have shown < 250 mV threshold voltage shifts for > 5000 hours under VGS=+25V and negligible threshold voltage shifts for > 2500 hours under VGS=-10V, both at T=175C. Under unclamped inductive switching, these 1200V, 80 mOhm SiC MOSFETs survive 1000 mJ of avalanche energy, meeting state-of-art ruggedness for 1200V SiC MOSFETs.


2009 ◽  
Vol 615-617 ◽  
pp. 557-560 ◽  
Author(s):  
Takuma Suzuki ◽  
Junji Senzaki ◽  
Tetsuo Hatakeyama ◽  
Kenji Fukuda ◽  
Takashi Shinohe ◽  
...  

The oxide reliability of metal-oxide-semiconductor (MOS) capacitors on 4H-SiC(000-1) carbon face was investigated. The gate oxide was fabricated by using N2O nitridation. The effective conduction band offset (Ec) of MOS structure fabricated by N2O nitridation was increased to 2.2 eV compared with Ec = 1.7 eV for pyrogenic oxidation sample of. Furthermore, significant improvements in the oxide reliability were observed by time-dependent dielectric breakdown (TDDB) measurement. It is suggested that the N2O nitridation as a method of gate oxide fabrication satisfies oxide reliability on 4H-SiC(000-1) carbon face MOSFETs.


2019 ◽  
Vol 963 ◽  
pp. 745-748 ◽  
Author(s):  
Daniel J. Lichtenwalner ◽  
Shadi Sabri ◽  
Edward van Brunt ◽  
Brett Hull ◽  
Satyaki Ganguly ◽  
...  

Gate oxide reliability on silicon carbide MOSFETs and large-area SiC N-type capacitors was studied for devices fabricated on 150mm SiC substrates. Oxide lifetime was measured under accelerated stress conditions using constant-voltage time-dependent dielectric breakdown (TDDB) testing, or ramped-voltage breakdown (RBD) testing. TDDB results from 1200V Gen3 MOSFETs reveal a field acceleration parameter of about 35 nm/V, similar to values reported for SiO2 on silicon. Temperature-dependent RBD tests of large capacitors from 25°C to 200°C reveal an apparent activation energy of 0.24eV, indicating that oxide lifetime increases as the temperature is decreased, as expected. Using this acceleration parameter and activation energy in the linear field model, the gate oxide lifetime from MOSFET TDDB testing extrapolates to greater than 108 hours at a gate voltage of 15 VGS at 175°C.


2008 ◽  
Vol 600-603 ◽  
pp. 791-794 ◽  
Author(s):  
Takuma Suzuki ◽  
Junji Senzaki ◽  
Tetsuo Hatakeyama ◽  
Kenji Fukuda ◽  
Takashi Shinohe ◽  
...  

The channel mobility and oxide reliability of metal-oxide-semiconductor field-effect transistors (MOSFETs) on 4H-SiC (0001) carbon face were investigated. The gate oxide was fabricated by using dry-oxidized film followed by pyrogenic reoxidation annealing (ROA). Significant improvements in the oxide reliability were observed by time-dependent dielectric breakdown (TDDB) measurement. Furthermore, the field-effect inversion channel mobility (μFE) of MOSFETs fabricated by using pyrogenic ROA was as high as that of conventional 4H-SiC (0001) MOSFETs having the pyrogenic-oxidized gate oxide. It is suggested that the pyrogenic ROA of dry oxide as a method of gate oxide fabrication satisfies both channel mobility and oxide reliability on 4H-SiC (0001) carbon-face MOSFETs.


2011 ◽  
Vol 679-680 ◽  
pp. 354-357
Author(s):  
Jody Fronheiser ◽  
Aveek Chatterjee ◽  
Ulrike Grossner ◽  
Kevin Matocha ◽  
Vinayak Tilak ◽  
...  

The gate oxide reliability and channel mobility of carbon face (000-1) 4H Silicon Carbide (SiC) MOSFETs are investigated. Several gate oxidation processes including dry oxygen, pyrogenic steam, and nitrided oxides were investigated utilizing MOS capacitors for time dependent dielectric breakdown (TDDB), dielectric field strength, and MOSFETs for inversion layer mobility measurements. The results show the C-face can achieve reliability similar to the Si-face, however this is highly dependent on the gate oxide process. The reliability is inversely related to the field effect mobility where other research groups report that pyrogenic steam yields the highest electron mobility while this work shows it has weakest oxide in terms of dielectric strength and shortest time to failure.


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