LOW COST IMPLANTATION INTO SILICON
The work outlined here concerns optimization of an "ion incrustation technique": implantation without mass separation, and pulsed annealing by YAG laser for production of junctions on silicon. The ion incrustation process is based on gas discharge in a gas containing the dopant (PF-5). The plasma established at a voltage of 6 to 10 kV creates an ion beam which is accelerated towards the substrates to be doped at voltages from 2 to 50 kV. The machine developed includes two work stations processing the wafers continuously: for doping and activation annealing by laser, respectively. In annealing, the pulses cause melting of a very small thickness of silicon followed by rapid epitaxial recrystallization which enables incorporation of heavy concentrations of dopant on the silicon substitution sites, a theoretical model indicates the level of energy required to melt a given thickness. The residual faults have been compared with results obtained in ruby laser annealing. Ion incrustation and pulsed laser annealing were applied to the production of mono-2 and polycrystalline silicon solar cells of 11 cm**2 area. This process has also been applied to different type of polycrystalline silicon; it has been demonstrated that atomic hydrogen can be used to remove the grain boundary effects. The possibilities of ion implantation without mass separation have been considered for passivation of grain boundaries.
Bibliographic Reference: EUR 9986 EN (1985) MF, 89 P., BFR 150, BLOW-UP COPY BFR 445, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989124106400 / Last updated on: 1987-01-01
Available languages: en