Abstract: An improved reactor for a high-temperature deposition reaction on seed particles is constructed with a fluidized bed which is divided into a heating zone and a reaction zone by a partition. Seed particles in the heating zone are fluidized by a carrier gas and are heated by microwaves. On the other hand, the reaction zone for the deposition reaction, through which reaction gases pass, is heated by particle mixing between the reaction zone and the upper section of the heating zone. Subsequently, a desired reaction temperature at the reaction zone is maintained stable without deteriorating the microwave heating of the heating zone.

Abstract: An improved method is provided for the deposition of high-purity silicon on silicon particles from silicon source gases in a fluidized bed reactor which is divided into a heating zone and a reaction zone by a partition. Silicon particles in the heating zone are fluidized by a carrier gas such as hydrogen and are heated by microwaves. On the other hand, the reaction zone for the deposition of silicon, through which reaction gases including the silicon source pass, is heated by particle mixing between the reaction zone and the upper section of the heating zone. Subsequently, a desired reaction temperature at the reaction zone is maintained stable without deteriorating the microwave heating of the heating zone.

Abstract: A jet pulverizing method is described for preparing silicon seed particles from silicon feed particles without contamination. The method comprises accelerating silicon feed particles by fluid jet energy and colliding them with each other within a pulverizing chamber to fracture or split them into small particles which are recovered for use as seed particles. The method is characterized by the technique that silicon particles fluidized within the pulverizing chamber are formed into a dilute-phase fluidized bed with low particle density. Thus, the generation of fine powders may be suppressed and additional sieving to separate larger particles is not required.

Abstract: A fabricating method of an ion sensitive field effect transistor (ISFET) with a Ta.sub.2 O.sub.5 hydrogen ion sensing membrane, which comprises the steps of forming Ta.sub.2 O.sub.5 film with a thickness of about 400 to 500 A by RF reactive sputtering on a Si.sub.3 N.sub.4 /SiO.sub.2 gate dielectric layer of the pH-ISFET, and annealing the resultant film at about 375.degree. to 450.degree. C. in oxygen gas ambience for about one hour. In forming the Ta.sub.2 O.sub.5 film on the pH-ISFET, the Ta.sub.2 O.sub.5 film formed in the area except the gate region of the pH-ISFET is removed by a lift-off process utilizing a positive PR film. The Ta.sub.2 O.sub.5 gate pH-ISFET according to the present invention has higher sensitivity and more stable operation characteristics than those of the conventional pH-ISFET, while the productivity and stability thereof are greatly improved by effecting a whole wafer process.