Diamond RF Transistor Technology with ft=41 GHz and fmax=44 GHz
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2018-06-01 |
| Authors | Tony Ivanov, James Weil, Pankaj B. Shah, A. Glen Birdwell, Khamsouk Kingkeo |
| Institutions | DEVCOM Army Research Laboratory |
| Citations | 21 |
Abstract
Section titled “Abstract”Initial results for diamond RF transistor technology are presented. Field Effect Transistors (FETs) were fabricated with gate lengths (L <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>g</sub> ) ranging from 4μm to 50nm. The FETs have total gate width (W <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>g</sub> ) of 40 or 120μm. L <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>g</sub> =100 nm devices show DC drain current I <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>D</sub> =600 mA/mm (V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>GS</sub> =-3V, V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>DS</sub> =-10V) with transconductance g <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>m</sub> =140mS/mm (V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>GS</sub> =-0.3V, V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>DS</sub> =-4V). Small signal S-parameters were measured to evaluate the high-frequency performance of the diamond FETs. Extrinsic f <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>t</sub> and f <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>max</sub> were measured to be 41GHz and 44GHz, respectively. Load pull measurements were used to characterize the devices under large signal excitation. The L <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>g</sub> =200nm, W <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>g</sub> =40μm device, tested at 2GHz, shows peak efficiency of 30.5% at V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>DS</sub> =-5V. Both peak gain of 19.5dB and peak output power density of 0.66W/mm were achieved at V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>DS</sub> =30V. Biasing the device at V <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>DS</sub> =-15V provides a trade off point for the large signal parameters - gain of ~15dB, efficiency of ~20%, and output power of ~0.5W/mm.
Tech Support
Section titled “Tech Support”Original Source
Section titled “Original Source”References
Section titled “References”- 2014 - C-H surface diamond field effect transistors for high temperature (400°C) and high voltage (500 V) operation [Crossref]
- 2005 - 2W/mm output power density at 1 GHz for diamond FETs