Abstract
III-V material such as GaN is very popular and promising semiconductor material, and can be obtained by external epitaxy growth . There are several kinds of substrate are developed in order to match the desire about getting those material,especially silicon. Silicon is common use in industry and low cost material compared to sapphire and SiC .It also more easier to achieve large-scale growth and mass production due to substrate size, but GaN on silicon will result in many problem caused by material property difference between them . The most critical issue is wafer bow due to huge CTE difference in two material . Those bow may influence the lithography accuracy or may lead wafer to break and be damaged in worst situation. For eliminating bow effect, we announce backside stress compensation layer by backside film deposition to achieve that . In order to select proper material serve as our stress compensation layer, we try Al2O3 and Si3N4 as candidate to make our pre-bow substrate . Also we confirm film’s property and bow magnitude caused by film . Filnally, we chose Si3N4 to create our backside film and also confirm the precise bow and curvature variation caused by film . After that we combine nanostructuring strengthening technology from our labs to our pre-bow substrate . The high-strength and pre-bow substrate was created and strength is larger than polished wafer by 1.5 fold. In final part, we use this kind of pre-bow wafer for GaN epitaxy . Comparing to normal polished wafer, we can eliminate the bow magnitude caused by GaN effectively and obtain more flat post-epi wafer.