InAlAs/InAs/InGaAs pseudomorphic high electron mobility transistors exhibiting ultra‐fast optical response

Abstract

High electron mobility transistors with a pseudomorphically strained InAs channel (InAs‐PHEMTs) have superior electron‐transport properties and high electron density, which are due to a large conduction‐band discontinuity. In this work, we demonstrate that InAs‐PHEMTs have an additional property: they exhibit an ultra‐fast optical response with a time‐constant of 3.5 × 10–11 s. By irradiating the optical signal onto the InAs‐PHEMTs, hole‐electron pairs are created in the channel layer. Holes accumulated in the source region of the channel layer recombine immediately with 2DEG due to an Auger recombination mechanism. Holes generated in the region outside the gate also recombine immediately with the 2DEG due to the Auger recombination mechanism before they drift or diffuse toward the gate region. This is why the optical response time of an InAs‐PHEMT is extremely small and it is restricted by the time for holes to transit across the gate region. A circuit incorporating an InAs‐PHEMT as a transistor and an InAlAs/InAs/InGaAs MSM photodiode that has the same structure as an InAs‐PHEMT as an optical detector has the potential to be applied as an ultra‐fast receiver optoelectronic integrated circuit. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Ultrafast Optical Response of InAlAs/InAs/InGaAs Pseudomorphic High Electron Mobility Transistors

“…6) In addition, we have demonstrated that InAs-PHEMT can operate as not only a high-speed transistor but also an ultra high-speed optical receiver. 7) In this work, we show the dependence of optical response on drain-to-source voltage (V DS ) for InAs-PHEMTs and clarify the physical mechanism for the response time. To physically understand the optical response, we estimated the minority carrier lifetime using the Auger recombination theory.…”

Dc and Rf Characteristics Fluctuation of Inalas/Ingaas Hemts According to the Operating Temperature Variation

“…We have been studying the physical properties of a phenomenon expressed in high electron mobility transistors (HEMTs) of the kind used in ultra-highspeed field effect transistors (FETs) [3][4][5]. Our previous research on inhibitors of carrier transport led us to propose fusing a high-speed device with a photo-responsive device [6].…”

Characteristics of PHEMTs and MSM photodetectors simultaneously fabricated on same epitaxial wafer with In0.75Ga0.25As/InGaAs channel layer

“…A current-gain cut-off frequency (f t ) of 628 GHz [2] and a maximum oscillation frequency (f max ) of 1.2 THz have been reported [1]. In our previous study regarding the effect of optical irradiation on InAlAs/InGaAs HEMT characteristics, we demonstrated that a shift of threshold voltage (V TH ) in InAlAs/InGaAs HEMTs is caused by the change in the Fermi level due to the holes accumulated in the source region [3,4]. The carrier lifetime of accumulated holes is dominated by Auger recombination of holes in the two-dimensional electron gas (2DEG) [3][4][5].…”

“…Furthermore, we have shown that InAlAs/InGaAs HEMTs have a high responsivity when they are used as optical receivers [5]. Recently, we have demonstrated that InAs-PHEMTs can operate as not only high-speed transistors but as ultra-high speed optical receivers [3][4][5][6].…”

“…In our previous study regarding the effect of optical irradiation on InAlAs/InGaAs HEMT characteristics, we demonstrated that a shift of threshold voltage (V TH ) in InAlAs/InGaAs HEMTs is caused by the change in the Fermi level due to the holes accumulated in the source region [3,4]. The carrier lifetime of accumulated holes is dominated by Auger recombination of holes in the two-dimensional electron gas (2DEG) [3][4][5]. Furthermore, we have shown that InAlAs/InGaAs HEMTs have a high responsivity when they are used as optical receivers [5].…”