Electrical properties of Si/SiO2/Si structures produced by direct bonding of pre-oxidized silicon wafers

The properties of BESOI p-Si/SiO2/p-Si and n-Si/SiO2/n-Si structures manufactured by direct bonding of pro-oxidized Czochralski p- and n-type (100) 2-40 Omega (.) cm silicon wafers were studied. Our study shows that the transversal static I-V and quasi-static C-V characteristics as well as the high-frequency emittance in the temperature range 77-300 K of BESOI structures with a buried oxide layer 2-100 nm thick are mainly dependent on the type of wafer conductance and the homogeneity of the oxide layer thickness. It was demonstrated that the electric properties of BESOI structures with an ultra-thin or thin separating BOX layer manufactured by direct bonding of pre-oxidized silicon wafers are strongly dependent on the parameters of the BOX layer (its thickness homogeneity), the state of Si/SoO(2) interfaces (hydrophilic, hydrophobic, contaminated by aluminum or not) and the origin of the Si/SiO2 interfaces both sides of the BOX layer (oxidation interface or bonding interface). The irradiation hardness of MOS devices manufactured from BESOI structures with a thick separating BOX layer is also strongly dependent on the origin of the Si/SiO2 interface. MOS devices, where the Si/SiO2 interface is a bonding interface, exhibited a greater hardness to gamma-irradiation than devices where the Si/SiO2 interface was an oxidation interface. (C) 2002 Elsevier Science B.V. All rights reserved.