Citation:
Bansal, A., Hergert, R., Dou, G., Wright, R.V., Bhattacharyya, D., Kirby, P.B., Yeatman, E.M. and Holmes, A.S., Laser transfer of sol-gel ferroelectric thin films using an ITO release layer, Microelectronic Engineering, 2011, Volume 88, Issue 2, Pages 145-149.
Abstract:
A new laser transfer process is reported which allows damage-free transfer of
ferroelectric thin films from a growth substrate directly to a target substrate.
The thin film ferroelectric material is deposited on a fused silica growth
substrate with a sacrificial release layer of ITO (indium tin oxide). Regions of
the film that are to be transferred are then selectively metallised, and bonded
to the target substrate. Separation from the growth substrate is achieved by
laser ablation of the ITO release layer by a single pulse from a KrF excimer
laser, with the laser light being incident through the growth substrate. The
residual ITO on the transferred ferroelectric layer is electrically conducting,
and may be suitable for incorporation into the final device, depending on the
application. The new process has been demonstrated for 500 nm-thick layers of
sol-gel PZT which were thermosonically bonded to a silicon target substrate
prior to laser release. The transferred films show ferroelectric behaviour and
have a slightly reduced permittivity compared to the as-deposit
