Point defects generated by direct-wafer bonding of silicon

Abstract

High-purity float zone (FZ) silicon p-and n-type wafers were directly bonded hydrophobically at 700°C and 1050°C. Electrical I-V and capacitance-voltage (C-V) characterization was performed on p-n junctions of 2-mm square chips cut out from properly bonded areas of the wafers. The point defects were investigated by Deep Level Transient Spectroscopy (DLTS). As expected, annealing at 700°C resulted in high void density, while at 1050°C void-free bonded structures were formed. The I-V characteristics were dominated by recombination at the bonded interface and by the resistance of the n-type wafer. The point defects identified by DLTS are divacancy, vacancy-phosphor, and vacancy-oxygen complexes. These defects explain qualitatively the observed characteristics of the samples.

Vertical Field-Plated NiO/Ga2O3 Heterojunction Power Diodes

“…In general, direct materials/wafer bonding/fusion of two monocrystalline semiconductors often leads to an interface layer having a high density of traps [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. These traps serving as recombination and generation centers cause non-ideal rectification current-voltage (I-V) behavior in p-n junctions, including high ideality factors, high reverse-bias leakage current, difficulty to achieve avalanche breakdown and impossible to reach desired depletion width.…”

Interface characterization of wafer bonding

“…There are five kinds of electron traps, together with two types of hole traps in Fig 2.9, all with different activation energy levels. Typical raw data obtained by using DLTS 50 tOO tH> ZOO 250 TO TEMSwwsri*ESK>Figure 2.9: Typical DLTS spectra using an instrument time constant of 6 ms[56]…”