Patent ID: 6221794
Filing Date: 2001-04-24
Classification: C23C,H01L

Abstract:
A submicron semiconductor technology process for minimizing thermal stress-induced voids in electrical interconnect line structures, said process comprising the steps of:a) providing at least one semiconductor substrate having a plurality of transistor gate structures, each transistor gate structure of said plurality of transistor gate structures having a width less than or equal to 0.25 .mu.m, and also having at least one pattern of electrical interconnect line structure formed thereon with a line spacing less than 0.35 .mu.m;b) preventing said interconnect line structure from experiencing yield stress due to restricted plastic deformation and to hydrogen embrittlement, and thereby minimizing thermal stress-induced voids in said electrical interconnect line structure by setting PECVD deposition parameters comprising setting a deposition temperature to less than 400 degrees Celsius (.degree. C.) setting a chamber pressure, a plurality of gas flow rates for producing an NH.sub.3 -free plasma, and a plasma-energizing power setting for producing a silicon oxynitride layer having a refractive index in a target range of 1.63 and 1.71, and then depositing a silicon oxynitride layer between and on top of said electrical interconnect line structure using PECVD techniques,where by said depositing step includes forming said NH.sub.3 -free plasma comprising nitrogen, nitrous oxide, and silane gases being dispensed at said set flow rates and being energized at said set plasma-energizing power setting by a radio frequency power source,whereby during a deposition heating period, said electrical interconnect line structure does not experience a yield stress and, therefore, is not plastically deformed,whereby during a post-deposition cooling period, minimization of thermal stress-induced voids is effected in said electrical interconnect line structure,whereby said depositing step comprises adjusting a combination of said energizing-power setting and said chamber pressure to yield said silicon oxynitride layer having said refractive index in said refractive index target range, andwhereby said energizing-power setting and said chamber pressure are adjusted in a range of 285-330 W and in a range of 2.5-6.0 Torr, respectively;c) testing said silicon oxynitride layer and determining that its refractive index is in said refractive index target range; andd) depositing a layer of silicon dioxide on top of said silicon oxynitride layer to complete the formation of an interlayer dielectric.