Patent Number: 
Section: claims

1. An ion implanter for implanting a substrate with a material comprising:an ion source;a beam line assembly configured to extract ions from said ion source to form an ion beam and direct said ion beam toward a substrate disposed on a substrate support;a mask disposed in front of said substrate, said mask having a plurality of apertures to allow respective portions of said ion beam through said mask toward said substrate; anda scanning assembly configured to move said substrate support with respect to said ion beam at a first scan rate when first portions of said substrate are aligned with said plurality of apertures and at a second scan rate when second portions of said substrate are aligned with said plurality of apertures wherein said first scan rate is faster than said second scan rate and said second scan rate corresponds to point contacts of a solar cell. 2. The ion implanter of claim 1 wherein said mask is fixedly disposed, with respect to said ion beam, in front of said substrate. 3. The ion implanter of claim 1 wherein said ion beam has a height dimension, said apertures having a length corresponding to said height dimension. 4. The ion implanter of claim 1 further comprising a cooling subassembly connected to said mask for maintaining a temperature of said mask. 5. The ion implanter of claim 1 wherein said second portions of said substrate have a higher dose rate of ions from said ion beam as compared to said first portions of said substrate. 6. The ion implanter of claim 5 wherein said second portions of said substrate correspond to said point contacts in said solar cell.