Nec Corporation

Tohru Aoyama

Tatsuya Suzuki

Seiichi Shishiguchi

There is provided a method of fabricating a semiconductor device, including the steps of forming an insulating film and an electrically conductive film on a silicon substrate, forming a first opening in the insulating film and a second opening in the electrically conductive film, the second opening having a smaller length than the first opening so that tunnel portions are formed in the insulating film below the electrically conductive film, and forming a Si,Ge,base epitaxial layer on the silicon substrate in the first opening of the insulating film, wherein a process gas for growing the Si,Ge,base epitaxial layer includes disilane, an etching gas includes chlorine, a ratio of the chlorine to the disilane is greater than {fraction (1/50)}, and a growth temperature is smaller than 640&deg; C. In accordance with the method, it is possible to form a SiGe base epitaxial film having a greater thickness at opposite ends thereof than a thickness at the center thereof. Hence, even if the SiGe epitaxial film is formed to have a great thickness at opposite ends thereof for making electrical contact with the electrically conductive film, a central portion of the SiGe epitaxial layer acting as a base can have a small thickness. As a result, whereas a SiGe base epitaxial layer occupied about 80% of a thickness of an insulating film in a conventional semiconductor device, the SiGe base epitaxial layer formed in the above-mentioned method merely occupies about 60-3% of a thickness of the insulating film. Thus, the SiGe base epitaxial layer can be formed thinner, which ensures a higher operation rate of a bipolar transistor.

Method of fabricating a semiconductor device having epitaxial layer

In order to reduce boron concentration between a silicon substrate and an Si or Si,Ge,layer which is epitaxially grown in a CVD (chemical vapor deposition) apparatus, the silicon substrate is pretreated, before being loaded into the CVD apparatus, such as to prevent the substrate from being contaminated by boron in a clean room. Further, in accordance with one embodiment, a CVD growth chamber itself is cleaned, before the substrate is loaded into the growth chamber, using an F,gas at a predetermined temperature of the substrate, thereby to remove boron residues in the growth chamber.

Method for boron contamination reduction in IC fabrication

It is an object of the invention to provide a CMOS device comprising p-channel FETs having shallow source and drain regions and a method for fabricating the same. A B-doped selective epitaxial layer is grown only on an area, where the source and drain regions of the p-channel FET is to be formed. Growth of the B-doped selective epitaxial layer on an area, where the source and drain regions of a n-channel FET is to be formed, is impeded by forming a amorphous region on the area corresponding to the n-channel FET.

Semiconductor device and method for manufacturing same

A vapor-phase growth system able to avoid fluctuation of the heating performance of a heater during repeated growth processes is provided. This system includes a reactor, a substrate holder for holding a substrate, and a heater for heating the substrate held by the holder. The holder and the heater are placed in an inner space of the reactor. The holder and the substrate held by the holder divide an inner space of the reactor to thereby form a growth chamber in which a thin film is grown during a growth process and a heater chamber in which the heater is placed. The holder has a supporting member on which the substrate is placed. At least a part of the member is made of the same material as that of the thin film. The supporting member is made of a SOI substrate.

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Tokyo, Japan

Tohru Aoyama