Fujitsu Corporation

Mamoru Maeda

Mikio Takagi

Fumitake Mieno

Yoshimi Shioya

Yuji Furumura

Takashi Eshita

Hajime Kamioka

Tsutomu Nakazawa

Tsunenori Yamauchi

Kanetake Takasaki

Takuya Watanabe

Takashi Ito

Takashi Kato

Takayuki Ohba

Atsuhiro Tsukune

Masaaki Ichikawa

Hidekazu Miyamoto

Kaoru Tanabe

Yasushi Ohyama

Shin-ichi Inoue

Yoshifumi Nomura

Yasushi Oyama

Akira Tabuchi

Norihisa Tsuzuki

Yasuo Uo-ochi

A bipolar transistor includes a base region made of silicon crystal doped with a first impurity to a first level so as to establish a first carrier concentration in the base region and an emitter region made of silicon crystal doped with a second impurity to a second level substantially larger than the first level by a predetermined factor so as to establish a second carrier concentration in the emitter region, in which the second impurity exceeds the solubility limit of the second impurity in silicon crystal. The first and second levels are chosen in such a range that a difference in the carrier concentrations between the emitter region and the base region decreases substantially with increasing impurity level in the base region.

Semiconductor device having a region doped to a level exceeding the

Method of manufacturing a semiconductor device having a region doped to

A semiconductor device comprises one or a plurality of thin film wiring layers made of aluminum containing carbon, so as to obtain hillock-free wiring layers. A method of forming the thin film wiring layer employs a plasma-enhanced chemical vapor deposition or a magnetron-plasma chemical vapor deposition to form the thin film wiring layer.

Semiconductor device having thin film wiring layer of aluminum

A method of selectively depositing tungsten upon a silicon semiconductor substrate. A silicon substrate is coated with a masking film of PSG or SiO.sub.2 that is patterned to provide an opening for forming an electrode or wiring. On a portion of the substrate in the opening, a layer of tungsten having a thickness of approximately 2000 .ANG. is deposited by a CVD method from an atomosphere containing a gaseous mixture of WF.sub.6 and H.sub.2 . During this processing, tungsten nucleuses deposit on the surface of the masking film as well. Before such nucleuses form a film, the deposition processing is discontinued and H.sub.2 gas is fed into the CVD apparatus to produce HF, which etches the surface of the masking film, and thus tungsten nucleuses are removed. The deposition and removal steps are repeated several times until the height of the deposited tungsten and the thickness of the masking film are essentially equal to present a flat surface. Aluminum film is deposited on the flat surface and patterned by lithography. The flat aluminum deposition allows fabrication of accurate and reliable wirings and facilitates production of VLSI of sub-micron order.

Method of selectively depositing tungsten upon a semiconductor substrate

A plasma CVD apparatus for forming a deposited film on a base body by introducing a gas of a compound into a chamber and converting the gas into plasma by applying a high frequency electric power, includes a gas feeding pipe leading from the exterior of the chamber into the interior of the chamber, and a heating device. The heating device heats at least a part of the gas feeding pipe inside the chamber, thereby preventing the gas from condensing or solidifying. With this apparatus, plasma CVD can stably be carried out using gases of various compounds which are liquid or solid at room temperature.

Apparatus for plasma chemical vapor deposition

A semiconductor device having a deposited phosphosilicate glass film, containing an insubstantial amount of hydrogen and a low phosphorus concentration, is manufactured at a high mass productivity. This semiconductor device is manufactured by first placing plural substrates for semiconductor devices to be treated in a reaction tube so that the main surfaces of the substrates are substantially vertically aligned with respect to one another and are substantially perpendicularly intersected by the central axis of the reaction tube, the reaction tube being provided with at least two gas feed pipes having plural small openings pierced along the longitudinal direction thereof. Second, a silicon compound gas is introduced through one of the gas feed pipes into the reaction tube and an oxidizing gas is introduced through the other of the gas feed pipes into the reaction tube, while the inside of the reaction tube is maintained a reduced low pressure, whereby phosphosilicate glass films are deposited on the main surfaces of the substrates.

Method for coating a semiconductor device with a phosphosilicate glass

A method of plasma enhanced chemical vapor deposition of a phosphosilicate glass film on a substrate from a reaction gas mixture including SiH.sub.4, N.sub.2 O and PH.sub.3 is disclosed. This deposition is effected under the conditions such that a mol ratio of N.sub.2 O to SiH.sub.4 (N.sub.2 O/SiH.sub.4) in the reaction gas mixture is 50 or more and that a mol ratio of PH.sub.3 to SiH.sub.4 (PH.sub.3 /SiH.sub.4) in the reaction gas mixture is 0.08 or less. In the phosphosilicate glass film thus deposited, no cracking occurs due to a high temperature heat-treatment and due to the stress, caused by cooling the deposited films to an ordinarily ambient temperature.

Method of plasma enhanced chemical vapor deposition of phosphosilicate

A selective oxidation process for producing a semiconductor device comprises the step of depositing a silicon oxynitride layer directly on a silicon substrate by a plasma chemical vapor deposition method. After a selective oxidation of the silicon substrate, the silicon oxynitride layer is removed.

Process of producing semiconductor devices by forming a silicon

A process for high pressure oxidation of silicon comprising the steps of inserting silicon wafers and an oxidizing substance into a quartz capsule sealing the quartz capsule gas-tightly by fusing, and heating the quartz capsule to generate a high pressure oxidizing atmosphere therein and to form an oxide film on the silicon wafers without a flow of the oxidizing atmosphere. In a case where water is used as the oxidizing substance, the water is frozen and the inside space of the quartz capsule is exhausted before the sealing operation. Furthermore, in a case where an oxidizing gas, e.g. oxygen gas, is used as the oxidizing substance, if the pressure of the gas is higher than the ambient pressure, the quartz capsule is cooled to decrease the gas pressure to a pressure below the ambient pressure before the sealing operation.

Process for high pressure oxidation of silicon

Epitaxial layers are formed by introducing a reaction gas mixture into a reaction vessel in which semiconductor substrates are located, under a pressure of not higher than 1333 Pa (10 Torr), and heating said semiconductor substrates by high frequency induction power so that layers grow epitaxially on said semiconductor substrates. The frequency f of high frequency power is not higher than 50 kHz, and the pressure P in said reaction vessel is maintained in the following range ##STR1## wherein, P is the pressure in units of Pa or Torr in the reaction vessel and f is the frequency in kHz of said high frequency power.

Process for producing epitaxial layers

Growing community of inventors

Tama, Japan

Mamoru Maeda