Papers by Author: M. Seacrist

Abstract: Kinetics of oxide layer dissolution and atomic structure of Si-Si interface in Si wafer bonded structures have been investigated by transmission electron microscopy. Samples of Si(001)/SiO2/Si(001) and Si(110)/SiO2/Si(001) structures were fabricated by direct hydrophilic wafer bonding of 200 mm wafers followed by high temperature annealing. It is found that the decomposition rate of oxide layer and formation of Si-Si bonded interface depends very much on lattice mismatch and twist angle.

Abstract: The need of an effective control of residual metal content inside the silicon epitaxial wafers is revamping for CCD and CMOS applications, which are very sensitive to small amount of heavy metals. The paper will discuss the strengths and the challenges associated to the integrated use of well known electrical techniques when metals like iron and molybdenum are present in concentration lower than 1E11 cm^3.

Abstract: This paper describes a series of electrical measurements and sample modifications that enabled the electrical properties of hybrid-orientation direct silicon bonded wafer interfaces to be determined. It is shown that the carrier transport across this near-surface (110)Si/(100)Si boundary is dictated by the defects present at the bond interface. These interface states are believed to pin the Fermi-level, producing a conduction barrier with a thermal activation energy Ea = 0.56eV. The defect band has been identified by deep-level transient spectroscopy and associated with the defect states typically observed in plastically deformed silicon. The carrier transport behavior across the bonding interface, as well as the observed interface trap levels are therefore attributed to the dislocation network present at the bonding interface. The spatial uniformity of the interface properties have been evaluated by TEM, electron-beam induced current microscopy, photoconductive decay and conduction measurements.