A Study on the Effect of P Concentrations of PSG Interlayers on the Yield Characteristics of the NMOS Devices

층간 절연막으로 쓰이는 PSG막의 P농도가 NMOS소자의 수율에 미치는 영향에관한 연구

In this study, phosphosilicate glass(PSG) film was deposited by the oxidation of phosphine (PH3) and silane(SiH4) in nitrogen ambient with a conventional conveyerized Atmospheric Pressure Chemical Vapor Deposition(APCVD)system and phosphorus concentration is measured by using FT-IR technique. The flow characteirstics and etch rate variations ofthe films, depending on phosphorus concentrations, are investigated. Special emphasis is focused on the yield variations of NMOS-based 256K DRAM with 1.2\ulcorner metallization spacing with increasing phosphorus concentrations. As a result, the data indicates that the fairly good yield can be obtained within the range of between 8 and 10wt% phosphorus concentration, which result in a slope of flow within 45\ulcorner10\ulcorner The analysi of failure mechanism is also accompanied.