Fabrication of ULSI highly Functional Thin Film employing High Rate and High Uniformity Digital CVD

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The goal of this study was to establish the digital CVD technology of the ULSI thin films which required filling to increasingly high aspect ratio gap/hole and high performance. The basic process is carried out by the atomic level repetition of one fundamental process of first adsorption of the deposition precursor and subsequently improvement of the film quality and their reactions such as oxidation with active species. At first, the multi-layr Si oxide/Si nitride film was studied to fill a interlayr insulator film to the high aspect ratio gap. For the purpose, TES (triethylsilane : Si (C_2H_5) H) which did not oxygen was adopted. Then, the organic Si film with 1nm thickness was deposited confrmably in the deep gap by the reaction of hydrogen (H) atoms to TES.The great improvement of the Si film quality was found out by irradiation of H atoms, thereby removing H bonds in this Si film. Thus, a multi-layr, stacked oxide/nitride film with 2.5 nm periodicity was obtained successfully by a … More lternate irradiation of oxygen atoms and ammonia radicals. This film showed high voltage-resistance. Secondly, the digital CVD of the low dielectric constant (low-k) film was studied to improve the high-speed of the ULSI devices. The origin of the low-k was considered to arise from materials produced by small number of valence electrons, thus deposition of films with chemical bonds such as B-C-H,B-N,C-H and C-F was investigated. Specific dielectric constant, epsilon of the SiOF film was 3.89 of high value because of liberation of F atoms during oxidation of the fluorinated Si film. However, the boron nitride film, the hydrocarbon film fabricated from triethylchlorine and cumene, respectively demonstrated epsilon =3 and 2.57. Furthermore epsilon of the fluorocarbon film was low value of 1.89. Finally, since the present digital CVD method required long fabrication time, the Si oxide CVD employing the ICP (Inductively Coupled Plasma) with SiCl_2H_2/O_2 was studied to solve the drawback of the digital CVD.In this study, it was found that reaction of the precursor with oxygen radicals deposited the Si oxide in the absence of the plasma. Hence, another ICP antenna was arranged in vicinity of the sample stage and the time-modulated Ar plasma was generated. Accordingly, the pulse, namely digital irradiation of Ar^+ ions realized filling of the oxide to the high aspect ratio gap. Less