High-production sputtering system for producing sensors
Cars can learn to be self-driving, ordinary citizens have a whole slew of measurement technology inside their smartphones, and hobbyists buy mini-computers and build automatic watering systems for their house plants. Complex automation is no longer expensive... and it takes a lot of sensors. Actually knowing the temperature, distance, pressure, force, humidity, pH value, gas concentration, etc. makes a theoretical simulation into something really helpful in everyday life. The market for inexpensive sensors is growing. As a consequence, more and more sensor manufacturers are asking themselves how they can manufacture smaller sensors with fewer expenses. The answer is: using thin-film technology.
Requirements for the system
The system is intended to produce sensors, i.e. PCB tracks, capacitors and resistors. For this, thin metal films are deposited over the entire surface of 100 mm x 100 mm wafers - structuring by laser or lithography is handled by the customer outside the system. The layer thickness tolerance should be less than +/- 5 % or less than +/- 10 %, depending on the sensor. Instead of individual layers, stacks of up to two different metals also need to be deposited using already defined recipes. In every case, good adhesion to the substrate is needed. Between 100 and 200 pieces of these wafers need to be coated every working day; in some cases even on both sides. The ability to expand the system in the future would be a great advantage since future sensor products may require additional materials.
Solutions to requirements
The FHR.Line.700.V is a compact in-line system where the substrate carrier travels through the system in an upright position. The 12-16 wafers to be coated are inserted and removed simultaneously via the same lock chamber. The lock chamber is round and equipped with a device that turns the substrate carrier around so that the rear of the wafers can also be coated. The process chamber is continuously evacuated and contains an etching unit for pre-cleaning and activation of the substrate surface (for better adhesion) as well as two planar DC sputter sources for metal deposition. Based on the active recipe, the substrate holder moves past these process stations at a defined speed and with a defined frequency. The process units are positioned on large doors for convenient access during maintenance. There is a large blind flange at the end of the process chamber for retrofitting additional process chambers if necessary. As is the case with all FHR systems, everything is automatically controlled per recipe and all data is recorded so that it can be traced later.
The special features of this system are:
- High productivity thanks to a coating surface of up to 500 mm x 500 mm
- Compact - the footprint of the system itself is only 0.9 m x 3.3 m
- Two-sided coating is possible
- Automated coating with full control over all process parameters