| Budget Amount *help |
¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Research Abstract |
Deposition of silicon dioxide by plasma-enhanced chemical vapor deposition (PECVD) technique using tetra-isocyanate-silane (Si (NCO) _4 : TICS) and oxygen for interlayr dielectric film application is proposed. This material system has an feature of no possibility of formation of H_2O molecules nor OH radicals during deposition. If deposited films were dense enough to prevent water penetration into the films, the films have a big advantage for solving the problem of poisoned via holes and threshold voltage variation because these were caused by H_2Oor OH radicals in SiO_2 interlayr. Film properties strongly depended on the deposition gas composition. The film which was deposited under an oxygen-rich condition and high temperature (300ﾟC) was "hydrogen-free SiO_2", which means that the films does not contaion water nor OH redicals. The film density, refractive index, resistivity, and dielectric constant were 2.3g/cm^3,1.46,5*10^<14>OMEGAcm, and 3.6, respectively. The etching rate by buffered HF was 330nm/min. The film quality degraded with decreasing deposition temperature, however, it can be improved by annealing at 300ﾟC after deposition. Interface trap density and fixed charge density were about 8*10^<10>cm^<-2>eV^<-1> and 2*10^<11>cm^<-2> respectively. Fluorine doping were also examined. Refractive index and dielectric constant were reduced by 8% and 3%, respectively.
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