Manufacturing Improvement Of The BCD Process

Power driver & management chip market grows fast as the higher level IT industry and economic growth.The process of BCD plays an irreplaceable role in power driver & management chip market since it can implements three different devices in one chip and also can use different device based on the requirement.In face of many difficulties during the development and manufacturing of the BCD process,the products can remain invincible only on the condition of the manufacturing process optimization,the solution of problems,the yield of the products.This dissertation makes a research on the optimization of the process about LDMOS,schottky barrier leakage and rear metal connection.The achievements of this dissertation are as follows:1.Optimization for the DIBL of LDMOS.Under our research,we find that the existing DIBL effect is different from the traditional one.Under principle analysis,validation and failure analysis,we find that it is the inclination angle of the photoresist that leads to the deviation of threshold voltage.The best way to fix this bug is to optimize lithography project.2.Improvement for metallization process and line process.Under normal process,too large resistance in metal silicon layer and schottky leak are found by clients' feedback.By research and test,we find that non-crystallizing treatment by silicon ion can fix big resistance problem,also we fix schottky leakage problem by optimize annealing temperature of silicide.3.Improvement for metallization process,After on-line detection,we find that the ring defect after aluminum deposition takes more important effects on products' yield and reliability.After our experiment analysis,we find that the low quality titanium nitride film will lead to this defect,and we chose the best way to fix this by considering production and cost control.Finally we chose the titanium nitride thin film thickness increased by 3% to suppress the generation of defects.For aluminum etched mound defects,the experience validation and analysis will say that the annealing process is the reason.The “1C2P” process will fix mound defects.The main motivation and target of this dissertation is not only to provide a way to solve problems during BCD process' s development and production,but also to optimize manufacturing process in time,and improve products' competitiveness by the process' s improvement.This paper focus on the optimization for the process defects during BCD's produce,and this will ensure the yield and reliability of the production.