A new method for the growth of silicon oxide layers below 300°C by use of catalytic activity of platinum overlayers

A new method to grow silicon oxide layers at temperatures below 300°C is developed using catalytic activity of platinum. In this method, a ca. 1 nm-thick chemical oxide layer is formed on the Si surface and then a ca. 3 nm-thick platinum layer is deposited on it. The thin chemical oxide layer effectively prevents the silicide formation and the Si outdiffusion, and consequently, a silicon oxide layer grows between the Pt layer and the Si substrate, but not formed on the Pt surface. When the device with the (ca. 3 nm-Pt/ca. 1 nm-chemical oxide/Si(100)) structure is kept at room temperature in air for a week, the thickness of the oxide layer increases to ca. 2.6 nm. Measurements of X-ray photoelectron spectra under biases show that the interface state density for this device is lower than that for the (ca. 3 nm-Pt/ca. 3–3.5 nm-thermal oxide/n-Si(100)) devices. After heat-treatments of the oxide layer with the Pt overlayer at 300°C for 1 h in oxygen, the oxide thickness increases to ca. 4.6 nm.