Temperature-dependent dc characteristics of an InGaAs∕InGaAsP heterojunction bipolar transistor with an InGaAsP spacer and a composite-collector structure

Abstract

Articles you may be interested inTemperature-dependent characteristics of an InP/InGaAs double heterojunction bipolar transistor with a stepgraded InAlGaAs collector Effect of composite collector design on the breakdown behavior of InGaP/GaAs double heterojunction bipolar transistorThe temperature-dependent dc characteristics of an interesting heterojunction bipolar transistor with an InGaAsP spacer and an InGaAs/ InGaAsP composite-collector structure are studied and demonstrated. By employing the intermediate band-gap In 0.72 Ga 0.28 As 0.61 P 0.39 material at the emitter-base and base-collector heterojunction, the electron blocking effect is effectively eliminated. The studied device gives the promising dc performances including the small offset and saturation voltages without degrading the breakdown behaviors. The typical incremental current gain of 114 and the maximum dc current gain of 118 are obtained. It is worthwhile to note that the desired current amplification over 11 decades of the magnitude of collector current I C is obtained in the studied device. Moreover, the switching or hysteresis phenomenon usually observed in InP-based devices is not seen in the studied device.

On the breakdown behaviors of InP/InGaAs based heterojunction bipolar transistors (HBTs)

“…As the temperature is elevated from 300 to 450 K, under the emitter current of I E = 1, 2 and, 3 mA, the a values are increased from 46 (990), 31 (890), and 28 (855) to 184 (3240), 108 (2115), and 80 (1760) cm À1 for device A1 (A2), respectively. Device A1 reveals relatively lower a values as compared with device A2 and the previously reports InP/InGaAs DHBTs with InGaAs/InGaAsP composite collector [9]. Furthermore, as the primary electron current increases, the measured a, at a fixed electric field E V , decreases gradually since the injected electrons start to modulate the effective doping and electric field in the collector space charge region and subsequently causes the decrease of a [17].…”

“…From experiment results, the I CO values of device A1 are less than those observed in device A2, InP/ InGaAs HBTs with an InAlGaAs [13] or an InGaAs collector [14], by one or two order in magnitude at room temperature. In our both devices, the dominance of electron multiplication behavior and the temperature effect depend significantly on the collector design [9]. At lower reverse bias, the I CO increases with temperature.…”

“…4. The corresponding results of an InP/InGaAs HBT with an InGaAs/InGaAsP composite collector presented by Chen et al [9] are also included for comparison. The electron ionization coefficient a is extracted as a function of the electric field E V in the collector as [15] a ¼ …”

“…2, the switching or hysteresis behaviors [12] in conventional DHBTs are not seen in device A1. Therefore, the tunneling effect in the C-B junction is negligible [9]. The commonbase breakdown voltage BV CBO of devices A1 and A2 as function of temperature is illustrated in the inset of Fig.…”

“…This certainly degrades the device performance. In order to overcome this drawback, various structure designs have been reported, such as the p-n pair, composite collector, and compositionally graded layer at the base-collector (B-C) junction [8][9][10]. Previously, an InGaAs/InAlAs chirped superlattice (CSL) of InP/InGaAs DHBTs was demonstrated [10].…”