Ion Implantor Function
Using for doping process of solar cell, PN junction-the cell power core is formed after ion implantation.PN junction Using Implant in solar process can greatly enhanced the uniformity and effectivity of PV Cell。
Key Technical Parameters
|
|
DG plasma（Simplant） |
Varian（Solion) |
|
Species |
B+,P+ |
P+ |
|
Energy |
5-40keV |
10--20keV |
|
Current |
B+:70mA P+:120mA |
P+:80mA |
|
Uniformity |
＞98% |
＞97% |
|
Throughput |
3000wafer/hour |
1000 wafer/hour |
|
Dimension（length×width×height） |
6×5×3米 |
9.7×5.2×2.6米 |
|
Cost |
0.03USD/wafer |
0.1 USD/wafer |
Ion Implant Features
Compared with traditional thermal diffusion:
◆Dose of the ion implanted to the silicon wafer can be controlled accurately. Doping with ion implant, the dose can be accurate to the level of ions quantity, which can form high quality PN junction. Traditional thermal diffusion is not able to do.
◆Implanted depth can be controlled accurately. Ion implant could adjust the beam energy freely, which will adjust the kinetic energy of ion to regulate the implanted depth. Traditional thermal diffusion mainly depends on the temperature and the time to control the implanted depth which belongs to fuzzy control.
◆High efficiency of convert rate from photo to electric. Comparing with traditional thermal diffusion, ion implant can promote 1.5%-3% photoelectric conversion efficiency of cell.
◆High uniformity of square-resist. Cause the beam uniformity is adjustable and controlled precisely, the square-resist can be controlled better than thermal diffusion.
Advantages of Simplant：
◆Large beam. Simplant can reach a maximum of above 120mA(P+).
◆B+ & P+ implant: Other ion implant manufacturers only can implant P+ ion, Simplant also can implant large beam B+ ion to satisfy different customer’s requirements.
◆Beam uniformity rate: Simplant’s beam utilization rate can reach 95%.
◆Beam uniformity: Simplant’s beam uniformity can reach above 98%.
◆High productivity. Currently, productivity of ion implant on the market is 1000 pieces per hour(take Varian’s Solion as an example),which will cause restriction to capacity of photovoltaic cell production line to affect the manufacturer's profit directly. Simplant's capacity can reach 3000 pieces per hour.
◆Low cost of process: Using Simplant, the comprehensive process cost can be controlled in about 2-3 cents per wafer.