Transfer of an ultrathin single crystal silicon film from a Silicon On Insulator to a polymer

Abstract : This study reports the manufacturing of Silicon On Polymer (SOP). It describes the transfer of a 200 mm diameter silicon thin film from a silicon on insulator (SOI) substrate to a flexible polymer. The thickness of the single-crystal silicon film was less than 200 nm and the transfer was achieved by bonding the SOI wafer to a temporary silicon carrier with an adhesive polymer. Various parameters of the transfer were investigated: adherence of the stack, temperature of bonding, temporary carrier and Si film thickness. The substrate and the SOI buried oxide were removed by mechanical grinding and chemical etching. The Si thin film was held on a flexible tape and the temporary carrier was dismounted. SOPs consisting of 20 to 205 nm thin Si films on a flexible polymer (230 μm) were successfully obtained. 200 mm diameter full wafers or patterned wafers could be transferred.