A Comparison of Analog Performance, Linearity, and Distortion Characteristics Between Symmetric InGaAs and Asymmetric InGaAs/InP MOSFETs

Abstract

In this article, we report an investigation of analog performance, linearity, and harmonic distortion (HD) characteristics for both symmetric and asymmetric InGaAs n-channel MOSFETs at elevated temperatures. Analog performance parameters such as transconductance and voltage gain are found to be better for the asymmetric InGaAs MOSFETs than their symmetric counterparts. The linearity metrics such as g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m2</sub> , g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m3</sub> , voltage intercept points 2 (VIP2), VIP3, IIP3, and third-order intermodulation distortion (IMD3) have been analyzed. Asymmetric devices are found to perform better in terms of linearity. Moreover, distortion is also found to be less for the asymmetric devices than the symmetric ones. A comparison of the linearity and distortion characteristics of InGaAs devices with a similarly sized Si device reveals that, although the Si device performs better in terms of linearity, particularly at elevated temperatures, InGaAs devices have an edge in terms of distortion over the Si device.