Pulsed laser deposition of electronic ceramics

High quality thin films of electronic ceramics are currently being deposited by pulsed laser deposition (PLD) for a variety of applications. Examples of these applications include ferroelectric thin films for active microwave electronics and rare-earth doped manganite thin films for uncooled infrared focal plane arrays (IRFPAs). Single phase and oriented SrxBa(1-x)TiO3 films have been deposited by PLD onto (100) substrates of LaAlO3 for active microwave devices. The dielectric properties of these films has been measured using gold interdigital capacitors deposited on top of the film. A 2: 1 change in the capacitance can be achieved using a 40 V bias across a 5-10 mu m capacitor gap. The dissipation factor (measured at 1 MHz) depends on film composition and temperature. Rare-earth manganite (RE(x)M(1-x)Mn(O delta)) thin films have also been deposited by PLD for use in uncooled IRFPAs, The temperature dependence of the resistivity has been measured for La0.67Ca0.33MnO3 and La0.67Sr0.33MnO3 thin films deposited onto LaAlO3 substrates. Film properties depend strongly on composition and post-deposition processing conditions to vary the oxygen stoichiometry. The temperature coefficient of resistance (TCR) has been measured to be between 2 and 15%. Based on preliminary measurements, these films will increase the sensitivity of the uncooled IR detector to be comparable or greater than a cooled detector based on HgCdTe.