National Science Council

Mau-Phon Houng

Yeong-Her Wang

Hwei-Heng Wang

Na-Fu Wang

Wai-Jyh Chang

Chien-Jung Huang

In the fabrication of gate oxides in IC process, a suitable cleaning/etching process is required to remove the native oxides and reduce surface microroughness in addition to standard RCA cleaning. For ultrathin oxide thickness (<10 nm), it is an important issue to have a native-oxide-free and H-passivated silicon (Si) surface to ensure high breakdown field, high charge-to-breakdown, and low leakage current. According to these concepts, we propose an invention with a simple two-step hydrogen fluoride (HF) etching process to improve the electrical properties of liquid-phase deposited fluorinated silicon oxides (LPD-SiOF), including effective removal of native oxides, lowering of interface trap density (&tilde;10 eV&minus;1 cm ), reduction of surface microroughness (Ra&equals;0.1 nm), and raising of breakdown field (&tilde;9.7 MV/cm). Furthermore, rapid thermal annealing (RTA) is also used to further improve the oxide quality. It is found that 18% increase of breakdown field and 33% reduction of interface trap density can be reached. In addition to the suitability for LPD-silicon oxides (SiO ), this technique is also suitable to other doped oxides. This technology is helpful to obtain a high quality and low cost silicon oxide for the ultrathin gate oxide in the future ULSI process.

Method of surface treatment on the improvement of electrical properties for doped silicon oxides (SiO2) films

Disclosed is a method for manufacturing a metal oxide semiconductor FET (MOSFET), which utilizes a low-temperature liquid phase oxidation for III-V group. The method includes the steps of (a) providing a substrate, (b) forming an epitaxial layer on the substrate, (c) defining and forming a drain and a source on a portion of the epitaxial layer, (d) forming a recess in an another portion of the epitaxial layer, (e) forming an oxide layer on a surface of the recess by relatively low-temperature oxidation, and (f) forming a gate on a portion of the oxide layer between the drain and source. In addition, the method further includes two selective procedures, that is, a synchronic sulfurated passivation process which can be performed with the growth of the oxide film simultaneously, and a rapid thermal annealing (RTA) process.

Method for fabricating metal oxide semiconductor field effect transistor (MOSFET)

A method for growing a silicon dioxide film on a HgCdTe substrate includes a first step in which the HgCdTe substrate is cleaned with an alkaline aqueous solution. The cleaned HgCdTe substrate is then dried before being immersed in a liquid phase deposition solution in which the silicon dioxide film is deposited on the surface of the HgCdTe substrate at the rate as high as 1672 .ANG./hr. The silicon dioxide film has a refraction rate as high as 1.465.

Liquid phase deposition method for forming silicon dioxide film on

A liquid phase deposition method involves the use of a supersaturated hydrofluosilicic acid aqueous solution for growing a silicon dioxide film at low temperature (30.degree. C.-50.degree. C.) on a III-V semiconductor, such as a gallium arsenide substrate. The silicon dioxide film may be used in a bipolar transistor or as a field oxide of MOS (metal oxide semiconductor). The III-V semiconductor substrate is chemically treated with an alkaline aqueous solution such as ammonium hydroxide so that the surface of the III-V semiconductor substrate is modified to facilitate the growth of the silicon dioxide film by liquid phase deposition. The growth rate of the silicon dioxide film is as fast as 1265 .ANG./hr. The silicon dioxide film has a refractive index ranging between 1.372 and 1.41.

Liquid phase deposition method for growing silicon dioxide film on III-V

A method is provided for forming an oxide film on a III-V substrate. The method includes steps of (a) preparing an acidic solution containing a IIIA-ion, (b) adding an basic solution into the acidic solution to provide a growth solution of a specific pH value, and (c) placing the III-V substrate into the growth solution to form the oxide film on the III-V substrate.

Growing community of inventors

Tainan, Taiwan

Mau-Phon Houng