Advanced processing for mobility improvement in 4H-SiC MOSFETs: A review

Abstract This paper reviews advanced gate dielectric processes for SiC MOSFETs. The poor quality of the SiO2/SiC interface severely limits the value of the channel field-effect mobility, especially in 4H-SiC MOSFETs. Several strategies have been addressed to overcome this issue. Nitridation methods are effective in increasing the channel mobility and have been adopted by manufacturers for the first generations of commercial power devices. Gate oxide doping techniques have also been successfully implemented to further increase the channel mobility, although device stability is compromised. The use of high-k dielectrics is also analyzed, together with the impact of different crystal orientations on the channel mobility. Finally, the performance of SiC MOSFETs in harsh environments is also reviewed with special emphasis on high temperature operation.

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

[2]  J. Cooper,et al.  Time-dependent-dielectric-breakdown measurements of thermal oxides on n-type 6H-SiC , 1999 .

[3]  J. W. Palmour,et al.  Electrical Properties and Interface Structure of SiC MOSFETs with Barium Interface Passivation , 2016, 2016 European Conference on Silicon Carbide & Related Materials (ECSCRM).

[4]  K. Ueno,et al.  Counter-doped MOSFETs of 4H-SiC , 1999, IEEE Electron Device Letters.

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

[6]  V. Afanas’ev,et al.  Detection and Electrical Characterization of Defects at the SiO2/4H-SiC Interface , 2010 .

[7]  T. Chassagne,et al.  Electrical properties of SiO 2 /SiC interfaces on 2°-off axis 4H-SiC epilayers , 2016 .

[8]  H. B. Weber,et al.  Effect of germanium doping on electrical properties of n-type 4H-SiC homoepitaxial layers grown by chemical vapor deposition , 2016 .

[9]  P. Godignon,et al.  Al-implanted on-axis 4H-SiC MOSFETs , 2017 .

[10]  V. Misra,et al.  Investigation of Lanthanum Silicate Conditions on 4H-SiC MOSFET Characteristics , 2015, IEEE Transactions on Electron Devices.

[11]  P. Godignon,et al.  Improved 4H-SiC N-MOSFET Interface Passivation by Combining N2O Oxidation with Boron Diffusion , 2016, 2016 European Conference on Silicon Carbide & Related Materials (ECSCRM).

[12]  Y. K. Sharma,et al.  Enhanced Field Effect Mobility on 4H-SiC by Oxidation at 1500°C , 2014, IEEE Journal of the Electron Devices Society.

[13]  Leonard C. Feldman,et al.  Channel Mobility Improvement in 4H-SiC MOSFETs Using a Combination of Surface Counter-Doping and NO Annealing , 2015 .

[14]  S. Dhar,et al.  Nitrogen Plasma Processing of SiO2/4H-SiC Interfaces , 2014, Journal of Electronic Materials.

[15]  Passivation and Generation of States at P-Implanted Thermally Grown and Deposited N-Type 4H-SiC/SiO2 Interfaces , 2016 .

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

[17]  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.

[18]  T. Oomori,et al.  Remarkable Increase in the Channel Mobility of SiC-MOSFETs by Controlling the Interfacial $\hbox{SiO}_{2}$ Layer Between $\hbox{Al}_{2}\hbox{O}_{3}$ and SiC , 2008, IEEE Transactions on Electron Devices.

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

[20]  J. W. Palmour,et al.  Insulator investigation on SiC for improved reliability , 1999 .

[21]  Sima Dimitrijev,et al.  Active defects in MOS devices on 4H-SiC: A critical review , 2016, Microelectron. Reliab..

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

[23]  Arun Gowda,et al.  Performance and Reliability of SiC MOSFETs for High-Current Power Modules , 2010 .

[24]  A. Schöner,et al.  3C-SiC MOSFET with High Channel Mobility and CVD Gate Oxide , 2011 .

[25]  K. Fukuda,et al.  Significant Improvement of Inversion Channel Mobility in 4H-SiC MOSFET on (11-20) Face Using Hydrogen Post-Oxidation Annealing , 2002 .

[26]  K. Shibata,et al.  Thermal oxidation temperature dependence of 4H-SiC MOS interface , 2006 .

[27]  Leonard C. Feldman,et al.  Effects of anneals in ammonia on the interface trap density near the band edges in 4H–silicon carbide metal-oxide-semiconductor capacitors , 2000 .

[28]  Jason P. Campbell,et al.  Time Dependent Dielectric Breakdown in High Quality SiC MOS Capacitors , 2016 .

[29]  V. Afanas’ev,et al.  Intrinsic SiC/SiO2 Interface States , 1997 .

[30]  J. M. Rafí,et al.  Impact of boron diffusion on oxynitrided gate oxides in 4H-SiC metal-oxide-semiconductor field-effect transistors , 2017 .

[31]  John W. Palmour,et al.  Improved oxidation procedures for reduced SiO2/SiC defects , 1996 .

[32]  H. Ólafsson,et al.  Sodium Enhanced Oxidation of Si-Face 4H-SiC: A Method to Remove Near Interface Traps , 2007 .

[33]  K. Matocha,et al.  Time-Dependent Dielectric Breakdown of 4H-SiC MOS Capacitors and DMOSFETs , 2008, IEEE Transactions on Electron Devices.

[34]  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.

[35]  Dominique Tournier,et al.  Process Optimisation for <11-20> 4H-SiC MOSFET Applications , 2006 .

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

[37]  Andre Stesmans,et al.  Mechanisms responsible for improvement of 4H-SiC/SiO2 interface properties by nitridation , 2003 .

[38]  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.

[39]  Heiji Watanabe,et al.  Study of SiO2/4H-SiC interface nitridation by post-oxidation annealing in pure nitrogen gas , 2015 .

[40]  Eisuke Tokumitsu,et al.  High channel mobility 4H-SiC metal-oxide-semiconductor field-effect transistor with low temperature metal-organic chemical-vapor deposition grown Al2O3 gate insulator , 2008 .

[41]  Masayuki Abe,et al.  Fabrication and Characterization of 3C‐SiC‐Based MOSFETs , 2006 .

[42]  K. S. Coleman,et al.  Energy-band alignment of HfO2/SiO2/SiC gate dielectric stack , 2008 .

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

[44]  P. Godignon,et al.  Oxidation Process by RTP for 4H-SiC MOSFET Gate Fabrication , 2011 .

[45]  Heiji Watanabe,et al.  Ultrahigh-Temperature Oxidation of 4H-SiC(0001) and an Impact of Cooling Process on SiO2/SiC Interface Properties , 2016, 2016 European Conference on Silicon Carbide & Related Materials (ECSCRM).

[46]  Akitaka Yoshigoe,et al.  Energy Band Structure of SiO2/4H-SiC Interfaces and its Modulation Induced by Intrinsic and Extrinsic Interface Charge Transfer , 2011 .

[47]  L. Feldman,et al.  Phosphorous passivation of the SiO2/4H–SiC interface , 2012 .

[48]  Scott Allen,et al.  High-Mobility SiC MOSFETs with Alkaline Earth Interface Passivation , 2016 .

[49]  A. Henry,et al.  Improved morphology for epitaxial growth on 4° off-axis 4H-SiC substrates , 2009 .

[50]  L. Feldman,et al.  The effect of nitrogen plasma anneals on interface trap density and channel mobility for 4H―SiC MOS devices , 2011 .

[51]  Kuan Yew Cheong,et al.  Current conduction mechanisms in atomic-layer-deposited HfO2/nitrided SiO2 stacked gate on 4H silicon carbide , 2008 .

[52]  C. Bongiorno,et al.  Effect of SiO2 interlayer on the properties of Al2O3 thin films grown by plasma enhanced atomic layer deposition on 4H‐SiC substrates , 2017 .

[53]  K. Wada,et al.  Improvement of Interface State and Channel Mobility Using 4H-SiC (0-33-8) Face , 2013 .

[54]  P. Godignon,et al.  SiC MOSFETs with thermally oxidized Ta2Si stacked on SiO2 as high-k gate insulator , 2008 .

[55]  J. Sumakeris,et al.  Investigations of 3C-SiC inclusions in 4H-SiC epilayers on 4H-SiC single crystal substrates , 1997 .

[56]  P. Godignon,et al.  A field-effect electron mobility model for SiC MOSFETs including high density of traps at the interface , 2006 .

[57]  Jeong Hwan Kim,et al.  Improved Electronic Performance of $\hbox{HfO}_{2}/ \hbox{SiO}_{2}$ Stacking Gate Dielectric on 4H SiC , 2007, IEEE Transactions on Electron Devices.

[58]  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 .

[59]  J. Cooper,et al.  Fundamentals of Silicon Carbide Technology: Growth, Characterization, Devices and Applications , 2014 .

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

[61]  A. Gobbi,et al.  SiC Nitridation by NH3 Annealing and Its Effects in MOS Capacitors with Deposited SiO2 Films , 2015, Journal of Electronic Materials.

[62]  K. Cheong,et al.  Electrical Properties of Atomic-Layer-Deposited La2O3/Thermal-Nitrided SiO2 Stacking Dielectric on 4H-SiC(0001) , 2007 .