A physical vapor deposition system includes a deposition chamber, a support to hold a substrate in the deposition chamber, a target in the chamber, a power supply configured to apply power to the target to generate a plasma in the chamber to sputter material from the target onto the substrate to form a piezoelectric layer on the substrate, and a controller configured to cause the power supply to alternate between deposition phases in which the power supply applies power to the target and cooling phases in which power supply does not apply power to the target. Each deposition phase lasts at least 30 seconds and each cooling phase lasts at least 30 seconds.