The Realization Of The Optimization Of Silicon Nitride Technology In PECVD System

With Nowadays,the PECVD(Plasma Enhanced Chemical Vapor Deposition)process has already became into an inseparable process link of optoelectronic device chip manufacturing process.Comparing to traditional high temperature oxidation process of tube furnace,PECVD process has some outstanding advantages such as low growth temperature,fast deposition rate,and less space demand,etc.It is well suitable for the process for production of ?-? compound semiconductor chips,which can be subjected to low service temperatures.Therefore,to study the suitable mass-producing PECVD process conditions and the process production status control method is an urgent demand for promoting the industrialization of optoelectronic chip components in the company.Aiming at the company's InGa As photoelectric detector chip industrialization requirements represented by 2.5 G APD(Avalanche Photo Diode),this thesis studied the influence factors of PECVD silicon nitride thin film technology in the process of photoelectric detector chip production.Besides,according to the requirement of mass production,this thesis carried out a series of related process tests and optimized and solidified the technological conditions.What's more,by using the SPC(Statistical Process Control),the advanced quality analysis method,the thesis analyzed the long run state of PECVD and fully verified the stability and repeatability of the optimized process conditions,which was eventually applied to guide actual production technique of PEC VD.Finally,it met the process need of 3million InGaAs photoelectric detector chips per month in the company.The concrete research contents are as follows:1.This thesis investigated the performance relationship of PEC VD process parameters and deposition of silicon nitride thin film.I t got the key features of the quantitative data of how chamber pressure,RF power,deposition temperature,gas ratio,ect.influence film refractive index and corrosion rate.It also analyzed its change rules.2.Various process experiments were designed by using the orthogonal test method,and the influencing factors of different influencing factors were determined.Through orthogonal method,this thesis acquired the best process conditions of PEC VD deposition of silicon nitride thin film by using PECVD process test technique and comprehensive analysis.It increased the process yield of silicon nitride films from 85% to over 98%,which effectively solving the problem o f low qualified rate.3.This thesis initially formed PECVD deposition process test database and established PECVD process optimization technique experimental methods and data analysis method,which solidified the production process specification and process inspection specifications.The corresponding production documents have been formed and have been reviewed and signed,and have been implemented in the production line.4.The SPC method was used to investigate the long-term stability of the optimized process parameters.After analysis,the optimized PECVD deposition of silicon nitride films is stable and can be used for the mass production of InGaAs detector chips...