Effect of surface passivation with SiN on the electrical properties of InP/InGaAs heterojunction bipolar transistors

Abstract

The effects of the SiN layer normally used to passivate and protect the exposed junction surfaces in InP/InGaAs heterojunction bipolar transistors have been studied and shown to degrade the transistor properties. These effects are ascribed primarily to surface damage associated with the high SiN deposition temperature (350 °C). A degradation of the emitter-base properties was observed through the nonideal behavior of the base current and the measured short minority-carrier lifetime in the base, extracted by using the base width modulation method. Degradation in the current gain and emitter injection efficiency was also observed. A clear recovery of the transistor was observed after removing the SiN passivation layer indicating that the high SiN deposition temperature results in a high-surface-state density which increases the surface recombination velocity and degrades the junction properties. It is concluded that a low-temperature deposition and good quality dielectric are necessary to exploit the excellent electrical properties of InP-based heterojunction bipolar transistors.

Passivation of InP heterojunction bipolar transistors by strain controlled plasma assisted electron beam evaporated hafnium oxide

“…13 Using m f ¼ 0. 3, the E f can be calculated to be 201 GPa, which is comparable to that given in the literature. 14 The measurements on MOS structures, shown in Fig.…”

“…The degradation of InP-based HBTs after PECVD-SiO 2 or SiN passivation has already been reported. 3,4,16,17 The increased leakage current has been generally attributed to the pinning of the surface Fermi level along passivated surfaces. The origin of the degradation could also be related to incorporation of fixed charges in the SiO 2 layer or at the dielectric/semiconductor interface.…”

“…In particular, in the case of InP-based heterojunction bipolar transistors (HBTs), the device characteristics are degraded after dielectric encapsulation using plasma enhanced chemical vapor deposition (PECVD)-based techniques. 3,4 Thus, various dielectric films and deposition techniques have been tested in the literature to improve the device characteristics.…”

Hafnium oxide passivation of InGaAs/InP heterostructure bipolar transistors by electron beam evaporation

“…In the case of InGaAs/InP heterostructure bipolar transistors (HBTs), the output characteristics are drastically degraded during or after SiO x or SiN x encapsulation using chemical vapour deposition (CVD)-based techniques [5][6][7].…”

Measurement and Simulation of Microwave Noise Transient of InP/InGaAs DHBT with Polyimide Passivattion

“…In recent years, many investigations have been conducted to study the effects of surface passivation on the performance of InP-based HBTs [1][2] [3]. The device passivation and protection for InP HBTs rely on the dielectric films such as silicon nitride, silicon oxide or polyimide.…”