High Mobility 4H-SiC MOSFETs Using Lanthanum Silicate Interface Engineering and ALD Deposited SiO2

In this work, we have developed a novel gate stack to enhance the mobility of Si face (0001) 4H-SiC lateral MOSFETs while maintaining a high threshold voltage. The gate dielectric consists a thin lanthanum silicate layer at SiC/dielectric interface and SiO2deposited by atomic layer deposition. MOSFETs using this interface engineering technique show a peak field effect mobility of 133.5 cm2/Vs while maintaining a positive threshold voltage of above 3V. The interface state density measured on MOS capacitor with lanthanum silicate interfacial layers is reduced compared to the capacitors without the silicate. It is shown that the presence of the lanthanum at the interface reduces the formation of a lower quality SiOxinterfacial layer typically formed at the SiC surface during typical high temperature anneals. This better quality interfacial layer produces a sharp SiC/dielectric interface, which is confirmed by cross section Z-contrast STEM images.

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Effect of High Temperature Forming Gas Annealing on Electrical Properties of 4H-SiC Lateral MOSFETs with Lanthanum Silicate and ALD SiO2 Gate Dielectric

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.482 ◽

2018 ◽

Vol 924 ◽

pp. 482-485

Author(s):

Min Seok Kang ◽

Kevin Lawless ◽

Bong Mook Lee ◽

Veena Misra

Keyword(s):

Threshold Voltage ◽

Interfacial Layer ◽

Field Effect ◽

Lanthanum Oxide ◽

Gate Dielectric ◽

High Mobility ◽

High Threshold ◽

Field Effect Mobility ◽

The Impact ◽

Lanthanum Silicate

We investigated the impact of an initial lanthanum oxide (La2O3) thickness and forming gas annealing (FGA) conditions on the MOSFET performance. The FGA has been shown to dramatically improve the threshold voltage (VT) stability of 4H-SiC MOSFETs. The FGA process leads to low VTshift and high field effect mobility due to reduction of the interface states density as well as traps by passivating the dangling bonds and active traps in the Lanthanum Silicate dielectrics. By optimizing the La2O3interfacial layer thickness and FGA condition, SiC MOSFETs with high threshold voltage and high mobility while maintaining minimal VTshift are realized.

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Improved Threshold Voltage Instability in 4H-SiC MOSFETs with Atomic Layer Deposited SiO2

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.498 ◽

2018 ◽

Vol 924 ◽

pp. 498-501 ◽

Cited By ~ 1

Author(s):

Min Seok Kang ◽

Bong Mook Lee ◽

Veena Misra

Keyword(s):

Threshold Voltage ◽

Atomic Layer ◽

Interface State ◽

State Density ◽

Threshold Voltage Shift ◽

Voltage Instability ◽

Effective Removal ◽

Metal Organic ◽

Organic Precursors ◽

Device Properties

This study reports the electrical characteristics and reliability of the atomic layer deposited SiO2 on the 4H-SiC substrate. By controlling the thickness of SiO2 in each ALD cycle, improved device properties like mobility and gate leakage were obtained as compared to the single deposition. Moreover, the optimized process dramatically reduces the threshold voltage shift under positive and negative bias stresses. This improvement can be attributed to the effective removal of unreacted metal-organic precursors, active traps, and broken bonds in the ALD SiO2 dielectrics as well as reduction in interface state density at SiC/SiO2 interface.

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Interface engineering of graphene–silicon Schottky junction solar cells with an Al2O3 interfacial layer grown by atomic layer deposition

RSC Advances ◽

10.1039/c7ra13443f ◽

2018 ◽

Vol 8 (19) ◽

pp. 10593-10597 ◽

Cited By ~ 7

Author(s):

Aaesha Alnuaimi ◽

Ibraheem Almansouri ◽

Irfan Saadat ◽

Ammar Nayfeh

Keyword(s):

Solar Cells ◽

Atomic Layer Deposition ◽

Interfacial Layer ◽

Aluminium Oxide ◽

Atomic Layer ◽

Schottky Junction ◽

Interface Engineering ◽

Layer Deposition ◽

Improved Performance

One approach to improve Gr/Si SBSC performance is engineering the interface with an interfacial layer. We demonstrate the improved performance of Gr/Si SBSC upon engineering the interface with an aluminium oxide (Al2O3) layer grown by atomic layer deposition (ALD)..

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Thin Film Transistors with High Mobility and High Threshold Voltage Stability Made Using Hot Wire Chemical Vapor Deposition

Japanese Journal of Applied Physics ◽

10.1143/jjap.45.4309 ◽

2006 ◽

Vol 45 (5B) ◽

pp. 4309-4312 ◽

Cited By ~ 8

Author(s):

Ruud E. I. Schropp

Keyword(s):

Thin Film ◽

Chemical Vapor Deposition ◽

Threshold Voltage ◽

Vapor Deposition ◽

Thin Film Transistors ◽

Voltage Stability ◽

High Mobility ◽

Chemical Vapor ◽

High Threshold ◽

Hot Wire

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Development and Characterization of High-Quality HfO2/InGaAs MOS Interface

Recent Advances in Nanophotonics - Fundamentals and Applications ◽

10.5772/intechopen.92424 ◽

2020 ◽

Author(s):

Sukeun Eom ◽

Min-woo Kong ◽

Kwang-seok Seo

Keyword(s):

Academic Research ◽

High Mobility ◽

Atomic Layer ◽

Deposition Process ◽

Nitrogen Plasma ◽

State Density ◽

Oxide Semiconductor ◽

High K ◽

Long Time ◽

High K Dielectric

The scope of this chapter is to introduce a highly efficient HfO2 atomic layer deposition (ALD) process with superior interface defect characteristics that can be applied on high-mobility III-V substrates. For a long time, the major academic research of III-V metal-oxide-semiconductor (MOS) studies was mainly oriented on searching for the suitable high-k dielectric, and among the reported high-k/III-V MOS studies, Al2O3 and AlN have demonstrated the most promising results. However, usually, the dielectrics with higher dielectric constant suffered from more defective interface quality including the HfO2, which should be overcome to meet the intensive operation voltage scaling requirements. In order to protect the interface of the HfO2/III-V MOS, the exposed III-V surface has to be carefully treated before, while, and after the whole high-k deposition process. For this purpose, the effect of isopropyl alcohol precursor and in situ cyclic nitrogen plasma treatment on the HfO2 ALD process at III-V substrates was thoroughly investigated. Remarkable interface state density levels with strong inversion behavior were achieved, which have not been observed at the previous HfO2/InGaAs studies. Also, detailed analysis of the interface characteristics was investigated to broaden the understanding of the improvement phenomenon.

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High Mobility 4H-SiC Lateral MOSFETs Using Lanthanum Silicate and Atomic Layer Deposited SiO2

IEEE Electron Device Letters ◽

10.1109/led.2015.2399891 ◽

2015 ◽

Vol 36 (4) ◽

pp. 312-314 ◽

Cited By ~ 16

Author(s):

Xiangyu Yang ◽

Bongmook Lee ◽

Veena Misra

Keyword(s):

High Mobility ◽

Atomic Layer ◽

Lanthanum Silicate

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Effect of post deposition annealing for high mobility 4H-SiC MOSFET utilizing lanthanum silicate and atomic layer deposited SiO2

2014 IEEE Workshop on Wide Bandgap Power Devices and Applications ◽

10.1109/wipda.2014.6964637 ◽

2014 ◽

Cited By ~ 1

Author(s):

Xiangyu Yang ◽

Bongmook Lee ◽

Veena Misra

Keyword(s):

High Mobility ◽

Atomic Layer ◽

Post Deposition Annealing ◽

Lanthanum Silicate ◽

Post Deposition

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Effect of Oxygen Source on the Various Properties of SnO2 Thin Films Deposited by Plasma-Enhanced Atomic Layer Deposition

Coatings ◽

10.3390/coatings10070692 ◽

2020 ◽

Vol 10 (7) ◽

pp. 692

Author(s):

Jong Hyeon Won ◽

Seong Ho Han ◽

Bo Keun Park ◽

Taek-Mo Chung ◽

Jeong Hwan Han

Keyword(s):

Electrical Properties ◽

Atomic Layer Deposition ◽

Carrier Concentration ◽

High Mobility ◽

Impurity Scattering ◽

Atomic Layer ◽

Growth Behavior ◽

Layer Deposition ◽

Growth Feature ◽

O2 Plasma

Herein, we performed a comparative study of plasma-enhanced atomic layer deposition (PEALD) of SnO2 films using Sn(dmamp)2 as the Sn source and either H2O plasma or O2 plasma as the oxygen source in a wide temperature range of 100–300 °C. Since the type of oxygen source employed in PEALD determines the growth behavior and resultant film properties, we investigated the growth feature of both SnO2 PEALD processes and the various chemical, structural, morphological, optical, and electrical properties of SnO2 films, depending on the oxygen source. SnO2 films from Sn(dmamp)2/H2O plasma (SH-SnO2) and Sn(dmamp)2/O2 plasma (SO-SnO2) showed self-limiting atomic layer deposition (ALD) growth behavior with growth rates of ~0.21 and 0.07–0.13 nm/cycle, respectively. SO-SnO2 films showed relatively larger grain structures than SH-SnO2 films at all temperatures. Interestingly, SH-SnO2 films grown at high temperatures of 250 and 300 °C presented porous rod-shaped surface morphology. SO-SnO2 films showed good electrical properties, such as high mobility up to 27 cm2 V−1·s−1 and high carrier concentration of ~1019 cm−3, whereas SH-SnO2 films exhibited poor Hall mobility of 0.3–1.4 cm2 V−1·s−1 and moderate carrier concentration of 1 × 1017–30 × 1017 cm−3. This may be attributed to the significant grain boundary and hydrogen impurity scattering.

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