Laser selective transfer process of barium strontium titanate (BST) on a sapphire substrate

We have been developing the laser selective transfer techniques to transfer Barium Strontium Titanate (BST), which has excellent dielectric properties, prepared on a heat-resistant sapphire substrate to the target substrate. As a sample, Pt/BST/Au structures were made on a sapphire substrate. The laser was irradiated from the backside of the substrate, which weakens Pt/sapphire adhesion. After the laser irradiation, the substrate was separated at Pt/sapphire interface and the BST was transferred to the target substrate. In order to optimize the laser irradiation conditions, the dependences of the transfer process on laser wavelengths (1064nm and 532nm) and pulsewidths (10ns and 200ns) were investigated. After the laser irradiation, we evaluated the shape and number of the BST pixels by adhesion tape test based on ISO2409. Shorter wavelength and longer pulsewidth gave us better results of damageless laser transfer process.