Patent ID: 9099584
Filing Date: 2015-08-04
Classification: H01L,Y02E,Y02P

Abstract:
1. A thin film silicon substrate comprising: a three dimensional structure defining a frontside and a backside of said substrate, said three dimensional structure comprising a mixture of a plurality of inverted pyramidal cavities and substantially flat areas; said substantially flat areas comprising: said inverted pyramidal cavities comprising pyramidal sidewalls defining said pyramidal cavities from said ridges to pyramidal apices on said backside of said thin film substrate; said thin film silicon substrate forming said ridges, linear regions, pyramidal sidewalls, and pyramidal apices having a substantially uniform layer thickness; a first conductivity type forming doped base regions; an emitter region having a second conductivity type on said frontside of said substantially flat areas of said thin film substrate; and metallization on said substantially linear regions of said thin film substrate and contacting said emitter region, wherein said metallization covers at most approximately 8% of said thin film substrate frontside.