| Autor: |
Palacios, Tomás, Rajan, Siddharth, Chakraborty, Arpan, Heikman, Sten, Keller, Stacia, Denbaars, Steven P., Mishra, Umesh K. |
| Předmět: |
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| Zdroj: |
IEEE Transactions on Electron Devices; Oct2005, Vol. 52 Issue 10, p2117-2123, 7p |
| Abstrakt: |
The decrease of transconductance gm and current gain cutoff frequency fT at high drain current levels in AIGaN/GaN high-electron mobility transistors (HEMTs) severely limits the linearity and power performance of these devices at high frequencies. In this paper, the increase of the differential source access resistance ra, with drain current is shown to play an important role in the fall of gm and fT. The increase of rs occurs due to the quasi-saturation of the electron velocity in the source region of the channel at electric fields higher than 10 kV/cm. This has been confirmed by both experimental measurements and two-dimensional drift-diffusion simulations. Through simulations, we have identified HEMT structures with source implanted regions (or n++ cap layers) as good candidates in order to increase the linearity of the gm and fT versus current profile. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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