The Study Of The Coating Of Silicon Dioxide By CVD Utilizing TEOS-O₃

SiO2 was deposited on the substrate utilizing tetraethoxysilane (TEOS)and O3 as precursors by chemical vapor deposition. For the atmospheric chemical vapor deposition the optimal experimental condition of coating is determined by the analysis of different temperature, different flow rate of TEOS and different O2/TEOS ratio. The uniform performance was tested by aqueous HF etch rate. At atmospheric pressure the results show : The deposition rate initially increases to a maximum and then begins to decrease with temperature rising. The etch rate appears to decrease and decling trend is slow gradually with temperature rising ,which means the uniformity of coating has been improved. The optimal temperature is about 400?; The deposition rate and the etch rate increase with flow rate of TEOS adding. The uniformity decreases quickly. So too fast deposition rate isn't propitious to the coating; The deposition rate and the etch rate decreases with O2/TEOS ratio increasing. The uniformity has been improved greatly. So the optimal O2/TEOS ratio is at least bigger than 4; In subatmospheric pressure the deposition rate initially increases to a maximum and then start decreasing with temperature rising. The etch rate decreases and dropping trend is slow gradually with temperature rising ,which means uniformity of coating has been improved. So the optimal temperature is about 450...