PREPARATION OF ULTRA LOW-K MATERIAL BY CHEMICAL VAPOR DEPOSITION METHOD.

以Si（NCO）_4、N（CH_3）_3和（C_6H_5）_2Si（N（CH_3）_2）_2为原料，在气相中制备了具有低介电常数k的多孔SiO_2薄膜。在解吸的苯基基团与Si的化学键合在所沉积的膜，膜显示出48%的孔隙率，和k低至2.5。低场电阻率约为10^ Ωcm，击穿场强<15>约为1.3MV/cm.在此基础上，指出了制备含亚烷基的多孔SiO_2薄膜的重要性，并论证了采用双（三乙氧基硅基）乙烯（BTE）水解缩合法制备的薄膜.以盐酸为催化剂，将BTE和H_2O与2-甲基-2，4-戊二醇（MPD）混合。在FT-IR中没有观察到MPD峰，但在450℃真空退火后仍观察到Si-C_2 H_4-Si相关峰。用MOS结构评价电特性。K值在400℃以下不受退火温度的影响，但在450℃时K值下降到1.9。为了确定薄膜的密度，对薄膜进行了X射线全反射和GIXA测量。经450℃真空退火后，薄膜的密度为1.2g/cm^3，孔隙率为52%。低介电常数薄膜在薄膜表面和薄膜与衬底的界面处有中间层，并尝试形成具有良好的耐热性和等离子体耐受性的含碳氟键的新型结构薄膜。为了形成CF结合膜，以下事情变得清楚。双（三氯硅基）乙炔[BTA]应与甲基反应，然后对BTA进行水解和缩合。

Porous silica films with a low dielectric constant, k, have been prepared from the gas phase using a mixture of Si(NCO)_4, N(CH_3)_3 and (C_6H_5)_2Si(N(CH_3)_2)_2. After desorption of phenyl groups chemically bonded with Si in the as-deposited film, the film showed a porosity of 48%, and k as low as 2.5. Low-field resistivity and break down field strength were about 10^<15> Ωcm, and 1.3MV/cm due to pinhals, respectively.Based on these results, importance of an Alkylene incorporated porous silica film I have been pointed out and demonstrated the film prepared by using hydrolysis and condensation of BIS(Triethoxysilyl)Ethelene (BTE). BTE and H_2O contained with HCl as a catalyst were mixture with organic solvent, 2-Methylpentane-2,4-diol (MPD). FT-IR peaks due to MPD were not observed but Si-C_2H_4-Si related peaks were still observed in the film even after 450℃ vacuum annealing. Electric characteristics were evaluated with an MOS structure. K value was not depended on the annealing temperature below 400℃, however, it was reduced down to 1.9 at 450℃. In order to confirm the density of the film X-ray total reflectance and GIXA measurement have applied to the films. The density of the film after vacuum annealing at 450℃ was 1.2g/cm^3 and porosity was 52%. The low-k film have inter mediate layers at surface the film and interface between low-k film and substrate.I have also tried to form new structure films incorporated with CF bonds which have good thermal and plasma tolerance. In order to form CF incorporated film, following things became clear. Bis(trichlorosilyl)acetylene [BTA] should be react with methyl groups and then hydrolysis and condensation applied to the BTA.