ASSP-22 – Al/ZnO Sputtering System

The Al/ZnO Sputtering System (ASSP) forms the rearmost conducting layers in photovoltaic modules. It uses physical vapor deposition (PVD) to sputter zinc-oxide and aluminum layers. The first one diffracts the sun light, while the latter one reflects it back to the amorphous silicon layer to increase the module’s efficiency. An 11.5 m long and nearly 8 ton machine that is a composition of 6 individual chambers – it can handle multiple panels at once.

The Sputter is entirely PLC controlled. The only manual operation is the sample load and unload in the case the automatic loader/unloader is not present. The system operator can follow the process on a single monitor with the help of a graphical user interface. The glowing plasma can be observed directly through shutter windows. A two-stage vacuum system provides uninterrupted PVD for both the zinc-oxide and the aluminum layers. The whole machine is designed to carefully secure the cleanness of the PV panels, thus minimizing refuse, ensuring an even layer deposition, and maximizing productivity.


Power: 73 kW
L × W × H: 11500 × 2200 × 2400 mm
Mass: 7500 kg
Work piece: 1245 × 635 mm (thickness: 3.0 ~ 3.3 mm)
Cycle time: under 75 sec (continuous sequential operation)
Process gases: Ar, N2, O2
Cooling: water, air
Valve actuation: pneumatic
Load/unload: manual or by panel lifter
PLC based safety interlock and process control system
Linear magnetron sputter source with 2×10 kW DC supply for Al
Rotating magnetron sputter source with 30 kW DC for ZnO
MFC controlled process gas inlet
Fore vacuum and high vacuum system
End vacuum: better than 2×10-6 mbar
Leakage: less than 2×10-9 mbar l/sec
Standard components from Pfeiffer, HSR and VAT