Evaluation of 4H-SiC Carbon Face Gate Oxide Reliability

2011 ◽  
Vol 679-680 ◽  
pp. 354-357
Author(s):  
Jody Fronheiser ◽  
Aveek Chatterjee ◽  
Ulrike Grossner ◽  
Kevin Matocha ◽  
Vinayak Tilak ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Inversion Layer ◽  
Gate Oxide ◽  
Dielectric Strength ◽  
Time To Failure ◽  
Research Groups ◽  
Mos Capacitors ◽  
Channel Mobility ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability

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.

Reliability of 4H-SiC(000-1) MOS Gate Oxide Using N2O Nitridation

2009 ◽  
Vol 615-617 ◽  
pp. 557-560 ◽  
Author(s):  
Takuma Suzuki ◽  
Junji Senzaki ◽  
Tetsuo Hatakeyama ◽  
Kenji Fukuda ◽  
Takashi Shinohe ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Band Offset ◽  
Mos Capacitors ◽  
Conduction Band Offset ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability ◽  
Mos Gate

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.

Effect of Gate Wet Reoxidation on Reliability and Channel Mobility of Metal-Oxide-Semiconductor Field-Effect Transistors Fabricated on 4H-SiC(000-1)

2008 ◽  
Vol 600-603 ◽  
pp. 791-794 ◽  
Author(s):  
Takuma Suzuki ◽  
Junji Senzaki ◽  
Tetsuo Hatakeyama ◽  
Kenji Fukuda ◽  
Takashi Shinohe ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Field Effect ◽  
Dielectric Breakdown ◽  
Field Effect Transistors ◽  
Gate Oxide ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Channel Mobility ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability

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.

950 Volt 4H-SiC MOSFETs: DC and Transient Performance and Gate Oxide Reliability

2008 ◽  
Vol 600-603 ◽  
pp. 1131-1134 ◽  
Author(s):  
Kevin Matocha ◽  
Zachary Stum ◽  
Steve Arthur ◽  
Greg Dunne ◽  
Ljubisa Stevanovic
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Time Dependent ◽  
Time To Failure ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability ◽  
Blocking Voltage ◽  
Mean Time

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.

Relation between Defects on 4H-SiC Epitaxial Surface and Gate Oxide Reliability

2013 ◽  
Vol 740-742 ◽  
pp. 745-748 ◽  
Author(s):  
J. Sameshima ◽  
Osamu Ishiyama ◽  
Atsushi Shimozato ◽  
K. Tamura ◽  
H. Oshima ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Oxide Thickness ◽  
Wafer Surface ◽  
Cross Sectional ◽  
Mos Capacitors ◽  
Oxide Breakdown ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability ◽  
Breakdown Region

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.

Gate Oxide Reliability of SiC MOSFETs and Capacitors Fabricated on 150mm Wafers

2019 ◽  
Vol 963 ◽  
pp. 745-748 ◽  
Author(s):  
Daniel J. Lichtenwalner ◽  
Shadi Sabri ◽  
Edward van Brunt ◽  
Brett Hull ◽  
Satyaki Ganguly ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Large Area ◽  
Temperature Dependent ◽  
Acceleration Parameter ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability ◽  
Voltage Breakdown ◽  
Linear Field

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.

Time Dependent Dielectric Breakdown in High Quality SiC MOS Capacitors

2016 ◽  
Vol 858 ◽  
pp. 615-618 ◽  
Author(s):  
Zakariae Chbili ◽  
Kin P. Cheung ◽  
Jason P. Campbell ◽  
Jaafar Chbili ◽  
Mhamed Lahbabi ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Oxide Thickness ◽  
Time Dependent ◽  
Production Environment ◽  
Early Failure ◽  
High Quality ◽  
Mos Capacitors ◽  
Time Dependent Dielectric Breakdown ◽  
Oxide Reliability

In this paper we report TDDB results on SiO2/SiC MOS capacitors fabricated in a matured production environment. A key feature is the absence of early failure out of over 600 capacitors tested. The observed field accelerations and activation energies are higher than what is reported on SiO2/Si of similar oxide thickness. The great improvement in oxide reliability and the deviation from typical SiO2/SiC observations are explained by the quality of the oxide in this study.

Characterization of 0.5 µm BiCMOS Gate Oxide Using Time Dependent Dielectric Breakdown Test

2010 ◽  
Vol 97-101 ◽  
pp. 40-44
Author(s):  
Mohd Zahrin A. Wahab ◽  
Azman Jalar ◽  
Shahrum Abdullah ◽  
Hazian Mamat
Keyword(s):  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Raw Material ◽  
Time Dependent ◽  
Process Equipment ◽  
Mos Capacitors ◽  
Time Dependent Dielectric Breakdown ◽  
Bicmos Technology ◽  
Set Up

This paper presents Time Dependent Dielectric Breakdown (TDDB) testing of gate oxide on 0.5µm BiCMOS Technology. The gate oxide quality for the technology has been investigated and furthermore to qualify the whole set up of the foundry from the process, equipment, cleanroom control and raw material used to produce high quality gate oxide and hence good quality of BiCMOS devices. TDDB test is the most widely used testing to check the quality of gate oxide and in this paper the TDDB test done on MOS capacitors fabricated using 0.5 µm BiCMOS Technology. Seven consecutive qualification lots have been tested and the data shown that TDDB measurement is capable to differentiate between accepted wafer and rejected wafer. The data also shown that TDDB test was capable to characterise 0.5 µm BiCMOS gate oxide with higher yield and comparable with reference lot from other foundry fab.

SiC MOSFET Reliability Update

2012 ◽  
Vol 717-720 ◽  
pp. 1073-1076 ◽  
Author(s):  
Mrinal K. Das ◽  
Sarah K. Haney ◽  
Jim Richmond ◽  
Anthony Olmedo ◽  
Q. Jon Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Time Dependent ◽  
Stable Operation ◽  
Gate Bias ◽  
Time Dependent Dielectric Breakdown ◽  
Mos Devices ◽  
Oxide Reliability ◽  
Made In

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.

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 ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Gate Oxide ◽  
Time Dependent ◽  
Operating Field ◽  
Time Dependent Dielectric Breakdown ◽  
Device Stability ◽  
Current Stressing ◽  
Oxide Reliability ◽  
Device Reliability ◽  
Post Stress

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.

Assessment of Reliability of cap layers used in Cu-Black DiamondTM Interconnects

2003 ◽  
Vol 766 ◽  
Author(s):  
Ahila Krishnamoorthy ◽  
N.Y. Huang ◽  
Shu-Yunn Chong
Keyword(s):  
Dielectric Layer ◽  
Dielectric Breakdown ◽  
Copper Ions ◽  
Dielectric Strength ◽  
Time Dependent ◽  
Breakdown Field ◽  
Field Range ◽  
Time Dependent Dielectric Breakdown ◽  
Voltage Ramp ◽  
Low K

AbstractBlack DiamondTM. (BD) is one of the primary candidates for use in copper-low k integration. Although BD is SiO2 based, it is vastly different from oxide in terms of dielectric strength and reliability. One of the main reliability concerns is the drift of copper ions under electric field to the surrounding dielectric layer and this is evaluated by voltage ramp (V-ramp) and time dependent dielectric breakdown (TDDB). Metal 1 and Metal 2 intralevel comb structures with different metal widths and spaces were chosen for dielectric breakdown studies. Breakdown field of individual test structures were obtained from V-ramp tests in the temperature range of 30 to 150°C. TDDB was performed in the field range 0.5 – 2 MV/cm. From the leakage between combs at the same level (either metal 1 or metal 2) Cu drift through SiC/BD or SiN/BD interface was characterized. It was found that Cu/barrier and barrier/low k interfaces functioned as easy paths for copper drift thereby shorting the lines. Cu/SiC was found to provide a better interface than Cu/SiN.

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