New spin-on, bonding compositions and methods of using those compositions are provided. The cured bonding compositions comprise a crosslinked oxazoline (either crosslinked with another oxazoline or with a crosslinking agent), and can be used to bond an active wafer to a carrier wafer or substrate to assist in protecting the active wafer and its active sites during subsequent processing and handling. The compositions form bonding layers that are chemically and thermally resistant, but that can be thermally decomposed at 285.degree. C. or higher to allow the wafers to slide apart at the appropriate stage in the fabrication process.