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

Abstract

In this contribution, we investigate the passivation of InGaAs/InP heterostructures using plasma assisted e-beam evaporated hafnium oxide (HfO 2). The microstructure and optical properties of the HfO 2 layers are first examined by X-ray reflectivity and spectroscopic ellipsometry on Si substrates. The current gain and breakdown voltage of InGaAs/InP heterostructure bipolar transistors (HBTs) have subsequently been used to evaluate the impact and efficiency of the e-beam evaporated HfO 2 passivation layers. The results from these structures have been contrasted with data from similar samples encapsulated with SiO 2 using conventional plasma enhanced chemical vapor deposition. The HfO 2 passivated InGaAs/InP HBTs show comparable current gains as compared to unpassivated structures. More importantly, in contrast to SiO 2-PECVD devices, the common emitter characteristics of HfO 2 passivated HBTs show no degradation in device breakdown voltage

Reactive magnetron sputtered hafnium oxide layers for nonvolatile semiconductor memory devices

“…7,8 Moreover, they can also be used as a passivation layer in devices dedicated for special applications such as high temperature and high power electronics based on silicon carbide (SiC) 9,10 or InGaAs/InP heterostructure bipolar transistors. 11 Hafnium oxide is also one of the functional layers in gas sensors, in particular, CO 2 (Ref. 12) or FETbased sensors for the detection of deoxyribonucleic acid hybridization.…”

Studies of Electrical Parameters and Thermal Stability of HiPIMS Hafnium Oxynitride (HfOxNy) Thin Films

“…Several high-k materials, including metal oxides [ 1 ], nanolaminates [ 2 ], and silicates [ 3 ], were intensively studied for their potential applications in high-performance or low-power complementary metal-oxide semiconductor (CMOS) devices. The commonly studied hafnium oxide (HfO 2 ) has proven wide applications [ 4 , 5 , 6 ], a relatively high permittivity value [ 7 ], a large band-gap [ 8 ], reasonably good band offset in contact with silicon substrate [ 9 ], and compatibility with polysilicon, as well as metal gate electrodes [ 10 ]. However, the crystallization temperature of HfO 2 is relatively low, leading to the growth of grain boundaries—which are perfect paths for oxygen, boron, and other impurities to penetrate into the semiconductor/dielectric interface [ 11 ].…”