Kabushiki Kaisha Toshiba

Katsunori Ishihara

Yuuichi Mikata

Katsuya Okumura

Kiyoshi Hisatomi

Sakae Funo

Toshiro Usami

In a silicon substrate, impurity diffusion layers, serving as source and drain regions, are formed to be separated from each other. A gate insulation film is formed on the silicon substrate between these source and drain regions. The gate insulation film is a silicon oxide film containing Cl having concentration of more than 1.times.10.sup.18 atoms/cm.sup.3 and less than 2.times.10.sup.20 atoms/cm.sup.3, and the gate insulation film is formed on the silicon substrate by low-pressure CVD. A gate electrode, formed of a polysilicon layer, is formed on the gate insulation film. An inter-level insulation film is formed on a resultant structure. A contact hole is formed on each of the source and drain regions of the inter-level insulation film. A drain electrode is formed on the inter-level insulation film, and connected to the drain region through the contact hole. A source electrode is formed on the inter-level insulation film, and connected to the source region through the contact hole.

Semiconductor device having insulation film whose breakdown voltage is

For providing a doped semiconductor film having a uniform thickness and a uniform impurity concentration on a semiconductor substrate, both a raw gas such as silane and an impurity gas such as phosphine are prepared. Thereafter, the raw gas is introduced into a reaction chamber, while a decomposed impurity gas, that is obtained by means for decomposing the impurity gas, is introduced into the reaction chamber, thereby depositing a doped semiconductor film such as a polysilicon film on the semiconductor substrate. A sub-reaction chamber, a plasma discharge device and a light source are used as the means for decomposing the impurity gas.

Method of making doped semiconductor film having uniform impurity

A semiconductor device includes a semiconductor substrate having a main surface, and a laminated structure. The laminated structure is made up of a nonmonocrystalline silicon layer and a layer of refractory metal or refractory metal silicide, formed on the nonmonocrystalline silicon layer, and formed on the main surface of the semiconductor substrate. The resistivity of the nonmonocrystalline silicon layer is set at less than substantially 1.times.10.sup.-2 .OMEGA..multidot.cm by doping an impurity thereinto at the time of deposition of the nonmonocrystalline silicon layer.

Method of forming a silicon semiconductor device using doping during

For providing a doped semiconductor film having uniform thickness and a uniform impurity concentration on a semiconductor substrate, both a raw gas such as silane and an impurity gas such as phosphine are prepared. Thereafter, the raw gas is introduced into a reaction chamber, while a decomposed impurity gas, that is obtained by means for decomposing the impurity gas, is introduced into the reaction chamber, thereby depositing a doped semiconductor film such as a polysilicon film on the semiconductor substrate. A sub-reaction chamber, a plasma discharge device and a light source are used as the means for decomposing the impurity gas.

A poly-Si film is formed on a first insulating film overlying a semiconductor substrate. A second insulating film is formed on the poly-Si film. The poly-Si film comprises a layered structure of a non-single crystal type silicon film and contains a phosphorus concentration of less than 5.times.10.sup.20 cm.sup.-3 or contains no phosphor, a poly-Si film having a phosphorus concentration of over 5.times.10.sup.20 cm.sup.-3 and a poly-Si film having a phosphorus concentration of less than 5.times.10.sup.20 cm.sup.-3 or containing no phosphorus. Since the phosphorus concentrations of the non-single crystal type silicon film adjacent to the first insulating film and poly-Si film adjacent to the second insulating film are reduced, the phosphorus in these two films are not diffused toward the corresponding insulating films. It is thus possible to improve the breakdown voltage across the first and second insulating films.

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Yokohama, Japan

Katsunori Ishihara