Characterization of SiO2/4H-SiC Interfaces in 4H-SiC MOSFETs: A Review

This paper gives an overview on some state-of-the-art characterization methods of SiO2/4H-SiC interfaces in metal oxide semiconductor field effect transistors (MOSFETs). In particular, the work compares the benefits and drawbacks of different techniques to assess the physical parameters describing the electronic properties and the current transport at the SiO2/SiC interfaces (interface states, channel mobility, trapping phenomena, etc.). First, the most common electrical characterization techniques of SiO2/SiC interfaces are presented (e.g., capacitance- and current-voltage techniques, transient capacitance, and current measurements). Then, examples of electrical characterizations at the nanoscale (by scanning probe microscopy techniques) are given, to get insights on the homogeneity of the SiO2/SiC interface and the local interfacial doping effects occurring upon annealing. The trapping effects occurring in SiO2/4H-SiC MOS systems are elucidated using advanced capacitance and current measurements as a function of time. In particular, these measurements give information on the density (~1011 cm−2) of near interface oxide traps (NIOTs) present inside the SiO2 layer and their position with respect to the interface with SiC (at about 1–2 nm). Finally, it will be shown that a comparison of the electrical data with advanced structural and chemical characterization methods makes it possible to ascribe the NIOTs to the presence of a sub-stoichiometric SiOx layer at the interface.

[1]  H. B. Harrison,et al.  INTERFACIAL CHARACTERISTICS OF N2O AND NO NITRIDED SIO2 GROWN ON SIC BY RAPID THERMAL PROCESSING , 1997 .

[2]  O. W. Holland,et al.  Improved inversion channel mobility for 4H-SiC MOSFETs following high temperature anneals in nitric oxide , 2001, IEEE Electron Device Letters.

[3]  M. White,et al.  Observation of near-interface oxide traps with the charge-pumping technique , 1992, IEEE Electron Device Letters.

[4]  A. Magna,et al.  Near interface traps in SiO2/4H-SiC metal-oxide-semiconductor field effect transistors monitored by temperature dependent gate current transient measurements , 2016 .

[5]  Alfredo Pasquarello,et al.  Charge transition levels of carbon-, oxygen-, and hydrogen-related defects at the SiC/SiO 2 interface through hybrid functionals , 2011 .

[6]  T. Kimoto,et al.  Interface Properties of 4H-SiC ( $11\bar {2}0$ ) and ( $1\bar {1}00$ ) MOS Structures Annealed in NO , 2015, IEEE Transactions on Electron Devices.

[7]  T. Umeda,et al.  Behavior of nitrogen atoms in SiC-SiO2 interfaces studied by electrically detected magnetic resonance , 2011 .

[8]  C. Bongiorno,et al.  Temperature-dependent Fowler-Nordheim electron barrier height in SiO2/4H-SiC MOS capacitors , 2017, 1903.08572.

[9]  Sima Dimitrijev,et al.  Direct Measurement of Active Near-Interface Traps in the Strong-Accumulation Region of 4H-SiC MOS Capacitors , 2018, IEEE Journal of the Electron Devices Society.

[10]  T. Fuyuki,et al.  Analysis of Anomalous Charge-Pumping Characteristics on 4H-SiC MOSFETs , 2008, IEEE Transactions on Electron Devices.

[11]  Chi On Chui,et al.  On the Correct Extraction of Interface Trap Density of MOS Devices With High-Mobility Semiconductor Substrates , 2008, IEEE Transactions on Electron Devices.

[12]  Peter Friedrichs,et al.  Charge Pumping Measurements on Differently Passivated Lateral 4H-SiC MOSFETs , 2015, IEEE Transactions on Electron Devices.

[13]  Interface passivation for silicon dioxide layers on silicon carbide , 2005 .

[14]  F. Giannazzo,et al.  Effects of interface states and near interface traps on the threshold voltage stability of GaN and SiC transistors employing SiO2 as gate dielectric , 2017 .

[15]  H. B. Weber,et al.  An adapted method for analyzing 4H silicon carbide metal-oxide-semiconductor field-effect transistors , 2019, Communications Physics.

[16]  C. L. Reynolds,et al.  Relationship between 4H-SiC∕SiO2 transition layer thickness and mobility , 2009 .

[17]  Hervé Morel,et al.  Threshold voltage instability in SiC MOSFETs as a consequence of current conduction in their body diode , 2018, Microelectron. Reliab..

[18]  S. Lorenti,et al.  A look underneath the SiO2/4H-SiC interface after N2O thermal treatments , 2013, Beilstein journal of nanotechnology.

[19]  B. Hull,et al.  Structure and chemistry of passivated SiC/SiO2 interfaces , 2016 .

[20]  Tsunenobu Kimoto,et al.  Generation of very fast states by nitridation of the SiO[2]/SiC interface , 2012 .

[21]  E. Schilirò,et al.  Negative charge trapping effects in Al2O3 films grown by atomic layer deposition onto thermally oxidized 4H-SiC , 2016 .

[22]  Aivars J. Lelis,et al.  Basic Mechanisms of Threshold-Voltage Instability and Implications for Reliability Testing of SiC MOSFETs , 2015, IEEE Transactions on Electron Devices.

[23]  Kenji Fukuda,et al.  Relationship between channel mobility and interface state density in SiC metal–oxide–semiconductor field-effect transistor , 2002 .

[24]  Hiroshi Yano,et al.  Improved Inversion Channel Mobility in 4H-SiC MOSFETs on Si Face Utilizing Phosphorus-Doped Gate Oxide , 2010, IEEE Electron Device Letters.

[25]  T. Fuyuki,et al.  Threshold Voltage Instability in 4H-SiC MOSFETs With Phosphorus-Doped and Nitrided Gate Oxides , 2015, IEEE Transactions on Electron Devices.

[26]  J. Montserrat,et al.  Evidence of Channel Mobility Anisotropy on 4H-SiC MOSFETs with Low Interface Trap Density , 2019, Materials Science Forum.

[27]  T. Kimoto.  Material science and device physics in SiC technology for high-voltage power devices , 2015 .

[28]  Anant K. Agarwal,et al.  Temperature Dependence of Inversion Layer Carrier Concentration and Hall Mobility in 4H-SiC MOSFETs , 2012 .

[29]  Scott Allen,et al.  High-Mobility SiC MOSFETs with Chemically Modified Interfaces , 2015 .

[30]  F. Giannazzo,et al.  Emerging trends in wide band gap semiconductors (SiC and GaN) technology for power devices , 2018 .

[31]  J. Millan,et al.  Field-effect mobility temperature modeling of 4H-SiC metal-oxide-semiconductor transistors , 2006 .

[32]  S. Dhar,et al.  High mobility 4H-SiC (0001) transistors using alkali and alkaline earth interface layers , 2014 .

[33]  H. Ohashi.  Power devices now and future, strategy of Japan , 2012, 2012 24th International Symposium on Power Semiconductor Devices and ICs.

[34]  D. Okamoto,et al.  Characterization of near-interface traps at 4H-SiC metal–oxide–semiconductor interfaces using modified distributed circuit model , 2017 .

[35]  F. Giannazzo,et al.  Challenges for energy efficient wide band gap semiconductor power devices , 2014 .

[36]  H. Yano,et al.  Hole trapping in SiC-MOS devices evaluated by fast-capacitance–voltage method , 2018 .

[37]  B. J. Baliga.  Silicon Carbide Power Devices , 2005 .

[38]  J. R. Williams,et al.  Scaling Between Channel Mobility and Interface State Density in SiC MOSFETs , 2011, IEEE Transactions on Electron Devices.

[39]  G. Duscher,et al.  Transition layers at the SiO2∕SiC interface , 2008 .

[40]  Peter Deák,et al.  Defects in SiO2 as the possible origin of near interface traps in the SiC∕SiO2 system: A systematic theoretical study , 2005 .

[41]  John W. Palmour,et al.  N2O Processing Improves the 4H-SiC:SiO2 Interface , 2002 .

[42]  S. Dimitrijev,et al.  Effects of nitridation in gate oxides grown on 4H-SiC , 2001 .

[43]  Andre Stesmans,et al.  Interfacial Defects in Si O 2 Revealed by Photon Stimulated Tunneling of Electrons , 1997 .

[44]  Hiroshi Yano,et al.  Improved Channel Mobility in 4H-SiC MOSFETs by Boron Passivation , 2014, IEEE Electron Device Letters.

[45]  T. Fuyuki,et al.  Improved Stability of 4H-SiC MOS Device Properties by Combination of NO and POCl3 Annealing , 2013 .

[46]  W. J. Choyke,et al.  Defect-engineering in SiC by ion implantation and electron irradiation , 2006 .

[47]  F. Giannazzo,et al.  Influence of the surface morphology on the channel mobility of lateral implanted 4H-SiC(0001) metal-oxide-semiconductor field-effect transistors , 2012 .

[48]  Anton J. Bauer,et al.  Comprehensive Study of the Electron Scattering Mechanisms in 4H-SiC MOSFETs , 2015, IEEE Transactions on Electron Devices.

[49]  T. Kimoto,et al.  Performance and reliability improvement in SiC power MOSFETs by implementing AlON high-k gate dielectrics , 2012, 2012 International Electron Devices Meeting.

[50]  D. Okamoto,et al.  Characterization of traps at nitrided SiO2/SiC interfaces near the conduction band edge by using Hall effect measurements , 2016, 1703.00615.

[51]  Michael C. Hamilton,et al.  High Channel Mobility 4H-SiC MOSFETs by Antimony Counter-Doping , 2014, IEEE Electron Device Letters.

[52]  Anant K. Agarwal,et al.  Hall mobility and free electron density at the SiC/SiO2 interface in 4H–SiC , 2000 .

[53]  F. Giannazzo,et al.  Nanoscale probing of the lateral homogeneity of donors concentration in nitridated SiO2/4H–SiC interfaces , 2016, Nanotechnology.

[54]  C. Bongiorno,et al.  Electron trapping at SiO2/4H-SiC interface probed by transient capacitance measurements and atomic resolution chemical analysis , 2018, Nanotechnology.

[55]  L. Feldman,et al.  Effect of nitric oxide annealing on the interface trap densities near the band edges in the 4H polytype of silicon carbide , 2000 .

[56]  F. Giannazzo,et al.  Limiting mechanism of inversion channel mobility in Al-implanted lateral 4H-SiC metal-oxide semiconductor field-effect transistors , 2011 .

[57]  Leonard C. Feldman,et al.  Effect of process variations and ambient temperature on electron mobility at the SiO/sub 2//4H-SiC interface , 2003 .

[58]  F. Giannazzo,et al.  Carrier Transport in Advanced Semiconductor Materials , 2008 .

[59]  Leonard C. Feldman,et al.  Fowler–Nordheim hole tunneling in p-SiC/SiO2 structures , 2000 .

[60]  Philippe Godignon,et al.  Advanced processing for mobility improvement in 4H-SiC MOSFETs: A review , 2017 .

[61]  Gerard Ghibaudo,et al.  Analytical study of the contribution of fast and slow oxide traps to the charge pumping current in MOS structures , 1996 .

[62]  T. Isaacs-Smith,et al.  High-Mobility Stable 4H-SiC MOSFETs Using a Thin PSG Interfacial Passivation Layer , 2013, IEEE Electron Device Letters.

[63]  K. Fukuda,et al.  High Temperature Rapid Thermal Oxidation and Nitridation of 4H-SiC in Diluted N2O and NO Ambient , 2005 .

[64]  G. Pobegen,et al.  Interface chemistry and electrical characteristics of 4H-SiC/SiO2 after nitridation in varying atmospheres , 2018 .

[65]  Ryoji Kosugi,et al.  Fixed nitrogen atoms in the SiO2/SiC interface region and their direct relationship to interface trap density , 2011 .

[66]  G. Groeseneken,et al.  A reliable approach to charge-pumping measurements in MOS transistors , 1984, IEEE Transactions on Electron Devices.

[67]  Mario Giuseppe Saggio,et al.  Fowler-Nordheim tunneling at SiO2/4H-SiC interfaces in metal-oxide-semiconductor field effect transistors , 2014 .

[68]  Marilena Vivona,et al.  Comparative study of gate oxide in 4H-SiC lateral MOSFETs subjected to post-deposition-annealing in N2O and POCl3 , 2014 .

[69]  K. Kita,et al.  Quantitative Characterization of Near-Interface Oxide Traps in 4H-SiC MOS Capacitors by Transient Capacitance Measurements , 2015 .

[70]  A. La Magna,et al.  SiO2/4H-SiC interface doping during post-deposition-annealing of the oxide in N2O or POCl3 , 2013 .

[71]  T. Kimoto,et al.  Reduction of interface state density in SiC (0001) MOS structures by post-oxidation Ar annealing at high temperature , 2017 .

[72]  W. Wang,et al.  The Effect of Gate Oxide Processes on the Performance of 4H-SiC MOSFETs and Gate-Controlled Diodes , 2008, IEEE Transactions on Electron Devices.

[73]  J. Cooper,et al.  Vertical Tri-Gate Power MOSFETs in 4H-SiC , 2018, Materials Science Forum.

[74]  L. Feldman,et al.  Oxidation induced stress in SiO2/SiC structures , 2017 .

[75]  Gregor Pobegen,et al.  Threshold voltage peculiarities and bias temperature instabilities of SiC MOSFETs , 2018, Microelectron. Reliab..

[76]  R. Iijima,et al.  Novel Gate Insulator Process by Nitrogen Annealing for Si-Face SiC MOSFET with High-Mobility and High-Reliability , 2018, Materials Science Forum.

[77]  Tsunenobu Kimoto,et al.  Accurate evaluation of interface state density in SiC metal-oxide-semiconductor structures using surface potential based on depletion capacitance , 2012 .

[78]  F. Giannazzo,et al.  Correlating macroscopic and nanoscale electrical modifications of SiO2/4H-SiC interfaces upon post-oxidation-annealing in N2O and POCl3 , 2012 .

[79]  D. Schroder.  Semiconductor Material and Device Characterization , 1990 .

[80]  V. Misra,et al.  High Mobility 4H-SiC Lateral MOSFETs Using Lanthanum Silicate and Atomic Layer Deposited SiO2 , 2015, IEEE Electron Device Letters.