Substrate exchange happens through the hinged door of a box-style PLD-3000 unit. No flanges or gaskets need to be removed for target changes in any of our PLD systems. Once the system is vented and the door is opened, one set of reflecting shields is removed to expose the substrate spinner assembly inside the black-body style heater. Substrate changes are accomplished with a pair of tweezers or needle-nose pliers. Note that substrates are held in a ring and contacted only at the substrate edges; no thermal paste or clamps are used. Thus, no cold spots are produced with this approach, and very uniform film properties are achieved.
Large area systems give you the opportunity to coat a variety of substrate sizes and shapes. Various substrate holders are available for our PLD-5000 system. Any substrate from 3 inches up to 5 inches can be coated along with multiple 2-inch or smaller samples. Custom holders can be made to accommodate your specific substrate sizes and needs for all of our PLD systems.
All of our box style PLD systems utilize our proprietary black-body substrate heater design. Bonding of the substrate to a heated back plate is not required with these heaters.
PVD Products uses banks of custom-designed IR heat lamps and is able to yield substrate temperatures of 850°C for materials such as sapphire and LaAlO3. Silicon or other absorbing materials can be readily heated to 950°C. A thermocouple in close proximity to the substrate spinner and a programmable closed-loop temperature control unit are used to maintain the substrate temperature during the entire film growth process. The black-body heater can also be used for post-deposition annealing of YBCO films up to pressures of 300 Torr of O2.
Substrates are held only at the edges and are not clamped in any way. They are heated by radiation alone and yield very uniform temperature profiles. The heaters and substrate rotation stage are completely surrounded by copper water-cooled shields that minimize the thermal load on the vacuum chamber walls. Slots machined into the water-cooled shields provide for laser beam access to the target surface as well as the ability to observe the laser plume and substrate during the deposition process.
Substrate changes are very easy with our substrate heater and spinner design. Substrates are simply placed into a substrate holder ring and then slipped into the spinner via hand or load lock transfer arm. The spinner is then retracted into the upper section of the heater housing using a motor-controlled linear transfer stage. A variety of substrate shapes and sizes can be handled with custom substrate holders. For instance, our PLD 5000 unit can handle four 50-mm diameter substrates along with four 1-cm square substrates at one time.