| A hot-wall type reactor has been designed for chemical vapor deposition at low pressure(LPCVD), and deposition of W on an oxide patterned Si-wafer has been studied. Utilizing scanning electron microscope and cross-sectional transmission electron microscopy, selective deposition of W only on the exposed Si surface has been confirmed. It has been observed that the microstructure of the W-film is strongly affected by flow rates, i.e., partial pressures of reaction gases(WF_6 H₂ and Ar). Fourpoint probe measurement of the thin film showed that porosity in the LPCVD W-film is one of major causes which increases sheet resistivity of the film, and the quantity of porosity is affected by reaction species and individual flow rates. |
|
