scholarly journals AlN/GaN-Based MOS-HEMT Technology: Processing and Device Results

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
S. Taking ◽  
D. MacFarlane ◽  
E. Wasige
Keyword(s):  
Ohmic Contact ◽  
Surface Passivation ◽  
Gate Dielectric ◽  
Process Development ◽  
Metal Deposition ◽  
Device Performance ◽  
Sidewall Passivation ◽  
Rf Performance ◽  
Wet Etch ◽  
Contact Optimisation

Process development of AlN/GaN MOS-HEMTs is presented, along with issues and problems concerning the fabrication processes. The developed technology uses thermally grown Al2O3as a gate dielectric and surface passivation for devices. Significant improvement in device performance was observed using the following techniques: (1) Ohmic contact optimisation using Al wet etch prior to Ohmic metal deposition and (2) mesa sidewall passivation. DC and RF performance of the fabricated devices will be presented and discussed in this paper.

FABRICATION TECHNIQUES FOR SELF-ALIGNED GaAs-BASED HBTs AND SUBMICRON GATE LENGTH FETs

1994 ◽  
Vol 08 (16) ◽  
pp. 2221-2243
Author(s):  
F. REN
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Ohmic Contact ◽  
Field Effect Transistors ◽  
Bipolar Transistors ◽  
Device Performance ◽  
Gate Length ◽  
Active Devices ◽  
Etching Selectivity ◽  
Gate Recess ◽  
Wet Etch

Process technologies for self-aligned AlGaAs/GaAs and InGaP/GaAs heterojunction bipolar transistors (HBTs) as well as gate definition and dry etching fabrication schemes for submicron gate length AlGaAs/GaAs-based field effect transistors (FETs) are presented. Multiple energy F + and H + ions were used to isolate the active devices for HBTs. The resistance of test wafers at 200° C showed no change over periods of more than 50 days. Highly selective dry and wet etch techniques for InGaP/GaAs and AlGaAs/GaAs material systems were used to uniformly expose heterojunctions. Reliability of the alloyed ohmic contact and feasibility of the nonalloyed ohmic contact metallizations for both p and n type GaAs layers will be discussed. The reproducible gate recess etching is one of the critical steps for AlGaAs/GaAs-based FETs. The etching selectivity, damage, pre- and post-clean procedures were studied in terms of device performance. A simple low temperature SiN x deposition and an etch-back process with optical stepper were used to demonstrate 0.1 µm Y-shape gate feature.

Fabrication Techniques for GaAs Based HBTS and FETs

1993 ◽  
Vol 300 ◽  
Author(s):  
F. Ren
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Ohmic Contact ◽  
Field Effect Transistors ◽  
Bipolar Transistors ◽  
Device Performance ◽  
Active Devices ◽  
Material Systems ◽  
Etching Selectivity ◽  
Gate Recess ◽  
Wet Etch

ABSTRACTProcess technologies for self-aligned AlGaAs/GaAs and lnGaP/GaAs heterojunction bipolar transistors (HBTs) as well as dry etching fabrication schemes for submicron AlGaAs/GaAs based field effect transistors (FETs) are presented. Multiple energy F+ and H+ ions were used to isolate the active devices for HBTs. The resistance of test wafers at 200 °C showed no change over periods of 50 days. Highly selective dry and wet etch techniques for InGaP/GaAs and AlGaAs/GaAs material systems were used to uniformly expose junctions. Reliability of the alloyed ohmic contact and feasibility of the non-alloyed ohmic contact metallizations for both p and n type GaAs layers will be discussed. The reproducible gate recess etching is one of the critical steps for AlGaAs/GaAs based FETs. The etching selectivity, damage, pre and post-clean procedure were studied in terms of device performance. A simple low temperature SiNx deposition and an etch-back process with optical stepper were used to demonstrate 0.1 μm Y-shape gate feature.

scholarly journals Combined Implications of UV/O3 Interface Modulation with HfSiOX Surface Passivation on AlGaN/AlN/GaN MOS-HEMT

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 136
Author(s):  
Soumen Mazumder ◽  
Ssu-Hsien Li ◽  
Zhan-Gao Wu ◽  
Yeong-Her Wang
Keyword(s):  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
Surface Passivation ◽  
Gate Dielectric ◽  
High Electron Mobility Transistors ◽  
Oxide Semiconductor ◽  
Device Performance ◽  
High Electron ◽  
Band Bending ◽  
Current Collapse

Surface passivation is critically important to improve the current collapse and the overall device performance in metal-oxide semiconductor high-electron mobility transistors (MOS-HEMTs) and, thus, their reliability. In this paper, we demonstrate the surface passivation effects in AlGaN/AlN/GaN-based MOS-HEMTs using ultraviolet-ozone (UV/O3) plasma treatment prior to SiO2 -gate dielectric deposition. X-ray photoelectron spectroscopy (XPS) was used to verify the improved passivation of the GaN surface. The threshold voltage (VTH) of the MOS-HEMT was shifted towards positive due to the band bending at the SiO2/GaN interface by UV/O3 surface treatment. In addition, the device performance, especially the current collapse, hysteresis, and 1/f characteristics, was further significantly improved with an additional 15 nm thick hafnium silicate (HfSiOX) passivation layer after the gate metallization. Due to combined effects of the UV/O3 plasma treatment and HfSiOX surface passivation, the magnitude of the interface trap density was effectively reduced, which further improved the current collapse significantly in SiO2-MOS-HEMT to 0.6% from 10%. The UV/O3-surface-modified, HfSiOX-passivated MOS-HEMT exhibited a decent performance, with IDMAX of 655 mA/mm, GMMAX of 116 mS/mm, higher ION/IOFF ratio of approximately 107, and subthreshold swing of 85 mV/dec with significantly reduced gate leakage current (IG) of 9.1 ×10−10 A/mm.

Metal Wet Etch Process Development for Dual Metal Gate CMOS

2005 ◽  
Vol 8 (12) ◽  
pp. G333 ◽  
Author(s):  
Muhammad Mustafa Hussain ◽  
Naim Moumen ◽  
Joel Barnett ◽  
Jason Saulters ◽  
David Baker ◽  
...  
Keyword(s):  
Process Development ◽  
Metal Gate ◽  
Dual Metal ◽  
Wet Etch

Slow surface passivation and crystal relaxation with additives to improve device performance and durability for tin-based perovskite solar cells

2018 ◽  
Vol 11 (9) ◽  
pp. 2353-2362 ◽  
Author(s):  
Efat Jokar ◽  
Cheng-Hsun Chien ◽  
Amir Fathi ◽  
Mohammad Rameez ◽  
Yu-Hao Chang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Surface Passivation ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Device Performance ◽  
Slow Surface ◽  
Effective Additive ◽  
Improve Device

Ethylenediammonium diiodide (EDAI2) served as an effective additive for tin-based perovskite solar cells to attain a power conversion efficiency approaching 9%.

Investigation of In Situ SiN as Gate Dielectric and Surface Passivation for GaN MISHEMTs

2017 ◽  
Vol 64 (3) ◽  
pp. 832-839 ◽  
Author(s):  
Huaxing Jiang ◽  
Chao Liu ◽  
Yuying Chen ◽  
Xing Lu ◽  
Chak Wah Tang ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Gate Dielectric
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