Sub-Micron Gate Length Field Effect Transistors as Broad Band Detectors of Terahertz Radiation

2016 ◽  
Vol 25 (03n04) ◽  
pp. 1640020 ◽  
Author(s):  
J. A. Delgado Notario ◽  
E. Javadi ◽  
J. Calvo-Gallego ◽  
E. Diez ◽  
J. E. Velázquez ◽  
...  
Keyword(s):  
Terahertz Radiation ◽  
Threshold Voltage ◽  
Field Effect ◽  
Room Temperature ◽  
Imaging System ◽  
Field Effect Transistors ◽  
Broad Band ◽  
Maximum Intensity ◽  
Gate Length ◽  
Electronic Source

We report on room temperature non-resonant detection of terahertz radiation using strained Silicon MODFETs with nanoscale gate lengths. The devices were excited at room temperature by an electronic source at 150 and 300 GHz. A maximum intensity of the photoresponse signal was observed around the threshold voltage. Results from numerical simulations based on synopsys TCAD are in agreement with experimental ones. The NEP and Responsivity were calculated from the photoreponse signal obtained experimentally. Those values are competitive with the commercial ones. A maximum of photoresponse was obtained (for all devices) when the polarization of the incident terahertz radiations was in parallel with the fingers of the gate pads. For applications, the device was used as a sensor within a terahertz imaging system and its ability for inspection of hidden objects was demonstrated.

scholarly journals The gamma-ray irradiation sensitivity and dosimetric information instability of RADFET dosimeter

2013 ◽  
Vol 28 (4) ◽  
pp. 415-421 ◽  
Author(s):  
Milic Pejovic
Keyword(s):  
Threshold Voltage ◽  
Field Effect ◽  
Room Temperature ◽  
Gamma Ray ◽  
Field Effect Transistors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Threshold Voltage Shift ◽  
Voltage Shift ◽  
Gamma Ray Irradiation

The gamma-ray irradiation sensitivity to radiation dose range from 0.5 Gy to 5 Gy and post-irradiation annealing at room and elevated temperatures have been studied for p-channel metal-oxide-semiconductor field effect transistors (also known as radiation sensitive field effect transistors or pMOS dosimeters) with gate oxide thicknesses of 400 nm and 1 mm. The gate biases during the irradiation were 0 and 5 V and 5 V during the annealing. The radiation and the post-irradiation sensitivity were followed by measuring the threshold voltage shift, which was determined by using transfer characteristics in saturation and reader circuit characteristics. The dependence of threshold voltage shift DVT on absorbed radiation dose D and annealing time was assessed. The results show that there is a linear dependence between DVT and D during irradiation, so that the sensitivity can be defined as DVT/D for the investigated dose interval. The annealing of irradiated metal-oxide-semiconductor field effect transistors at different temperatures ranging from room temperature up to 150?C was performed to monitor the dosimetric information loss. The results indicated that the dosimeters information is saved up to 600 hours at room temperature, whereas the annealing at 150?C leads to the complete loss of dosimetric information in the same period of time. The mechanisms responsible for the threshold voltage shift during the irradiation and the later annealing have been discussed also.

A Threshold Voltage Simulation of Hydrogen-Terminated Diamond MESFETs

2012 ◽  
Vol 482-484 ◽  
pp. 1093-1096 ◽  
Author(s):  
Xiao Feng Zhuang ◽  
Qing Kai Zeng ◽  
Bing Ren ◽  
Zhen Hua Wang ◽  
Yue Lu Zhang ◽  
...  
Keyword(s):  
Threshold Voltage ◽  
Diamond Film ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Drain Current ◽  
Diamond Surface ◽  
Gate Length ◽  
Simulation Results ◽  
Surface Conduction ◽  
Conduction Layer

In this paper, the threshold voltage of diamond film-based metal-semiconductor field effect transistors (MESFETs) has been simulated using Silvaco TCAD tools. The drain current (Id) versus gate voltage (Vg) relationship, and the distribution of acceptors in diamond surface conduction layer were also investigated. From the simulation results, it was found that the gate length contributed the most to the threshold voltage, while the doping depth almost had no impact on the threshold voltage value.

Cubic AlGaN/GaN Hetero-Field Effect Transistors with Normally On and Normally Off Operation

2009 ◽  
Vol 1202 ◽  
Author(s):  
Donat J. As ◽  
Elena Tschumak ◽  
Florentina Niebelschüetz ◽  
W. Jatal ◽  
Joerg Pezoldt ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Carrier Concentration ◽  
Field Effect ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Field Effect Transistors ◽  
Gate Length ◽  
Dc Characteristics ◽  
Threshold Voltages ◽  
Source Voltage

AbstractNon-polar cubic AlGaN/GaN HFETs were grown by plasma assisted MBE on 3C-SiC substrates. Both normally-on and normally-off HFETs were fabricated using contact lithography. Our devices have a gate length of 2 μm, a gate width of 25 μm, and source-to-drain spacing of 8 μm. For the source and drain contacts the Al0.36Ga0.64N top layer was removed by reactive ion etching (RIE) with SiCl4 and Ti/Al/Ni/Au ohmic contacts were thermally evaporated. The gate metal was Pd/Ni/Au. At room temperature the DC-characteristics clearly demonstrate enhancement and depletion mode operation with threshold voltages of +0.7 V and −8.0 V, respectively. A transconductance of about 5 mS/mm was measured at a drain source voltage of 10 V for our cubic AlGaN/GaN HFETs, which is comparable to that observed in non-polar a-plane devices. From capacity voltage measurements a 2D carrier concentration of about 7×1012 cm-2 is estimated. The influence of source and drain contact resistance, leakage current through the gate contact and parallel conductivity in the underlaying GaN buffer are discussed.

Anomalous Gate Length Dependence of Threshold Voltage of Trench-Isolated Metal Oxide Semiconductor Field Effect Transistors

1998 ◽  
Vol 37 (Part 2, No. 7B) ◽  
pp. L852-L854 ◽  
Author(s):  
Toshiyuki Oishi ◽  
Katsuomi Shiozawa ◽  
Akihiko Furukawa ◽  
Yuji Abe ◽  
Yasunori Tokuda
Keyword(s):  
Metal Oxide ◽  
Threshold Voltage ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Gate Length ◽  
Length Dependence

Double‐Gate MoS 2 Field‐Effect Transistors with Full‐Range Tunable Threshold Voltage for Multifunctional Logic Circuits

2021 ◽  
pp. 2101036
Author(s):  
Jiali Yi ◽  
Xingxia Sun ◽  
Chenguang Zhu ◽  
Shengman Li ◽  
Yong Liu ◽  
...  
Keyword(s):  
Threshold Voltage ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Full Range ◽  
Logic Circuits ◽  
Double Gate

Threshold-Voltage-Shift Mechanism in Pentacene Field Effect Transistors Caused by Photoirradiation

2008 ◽  
Vol 47 (4) ◽  
pp. 3189-3192 ◽  
Author(s):  
Chang Bum Park ◽  
Takamichi Yokoyama ◽  
Tomonori Nishimura ◽  
Koji Kita ◽  
Akira Toriumi
Keyword(s):  
Threshold Voltage ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Threshold Voltage Shift ◽  
Voltage Shift

Development of 8 mΩ-cm2, 1.8 kV 4H-SiC DMOSFETs

2006 ◽  
Vol 527-529 ◽  
pp. 1261-1264 ◽  
Author(s):  
Sei Hyung Ryu ◽  
Sumi Krishnaswami ◽  
Brett A. Hull ◽  
Bradley Heath ◽  
Mrinal K. Das ◽  
...  
Keyword(s):  
Threshold Voltage ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Gate Length ◽  
Gate Bias ◽  
Low Loss ◽  
Layer Resistance ◽  
Switching Characteristics ◽  
Mos Gate ◽  
Drift Layer

8 mΩ-cm2, 1.8 kV power DMOSFETs in 4H-SiC are presented in this paper. A 0.5 μm long MOS gate length was used to minimize the MOS channel resistance. The DMOSFETs were able to block 1.8 kV with the gate shorted to the source. At room temperature, a specific onresistance of 8 mΩ-cm2 was measured with a gate bias of 15 V. At 150 oC, the specific onresistance increased to 9.6 mΩ-cm2. The increase in drift layer resistance due to a decrease in bulk electron mobility was partly cancelled out by the negative shift in MOS threshold voltage at elevated temperatures. The device demonstrated extremely fast, low loss switching characteristics. A significant improvement in converter efficiency was observed when the 4H-SiC DMOSFET was used instead of an 800 V silicon superjunction MOSFET in a simple boost converter configuration.

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