Abstract: There is disclosed in hydrothermal process for producing a magnetoplumbitic ferrite powder of the formula:MO.n(Fe.sub.2-x M'.sub.x O.sub.3) (1)wherein M is one or more metals selected from the group consisting of Ba, Sr, Ca and Pb; n is a number of 3 to 6; M' is at least one component selected from the group consisting of Si, Ta, Sb, Nb, Zr and Ti, or a combination of that component with at least one other component selected from the group consisting of Ni, Co, Cu, Mg, Mn and Zn; x is a number of 0.01 to 0.7, which process comprises carrying out the reaction of said ferrite powder formation in a H.sub.2 O medium at a temperature higher than 100.degree. C. and in the presence of an alkali having an alkali equivalent ratio greater than 1.0 with respect to an acid residue or in the presence of an alkali that provides the reaction system with a pH of 11 or more, said reaction being caused to proceed in the presence of "agent A" or in the present of both "agent A" and "agent B".

Abstract: This invention relates to an apparatus for thermal diffusion by means of high frequency induction heating suitable for mass production of semiconductor substrates of uniform quality; wherein a plurality of heating bases, each made of a material having good electric conductivity, and carrying semiconductor substrates, are continuously fed through a furnace tube where the bases are heated by means of high frequency wave excitation in order that each semiconductor substrate receives substantially the same thermal treatment.

Abstract: A gaseous atmosphere control apparatus for heat-treating semiconductors in a uniform gaseous atmosphere condition is disclosed. The control apparatus is provided with a reaction pipe through which semiconductor wafers are transferred to be heat-treated. A gas distribution pipe is fixed to the inside wall of the reaction pipe for guiding the transfer of the wafers and supplying heat-treating gas in the reaction pipe. The distribution pipe is provided with a plurality of blow-off holes, the diameter thereof being made wider as the pipe extends longitudinally, to thereby control the gaseous atmosphere condition in the reaction pipe to be uniform.

Abstract: The invention discloses an apparatus for thermal diffusion of semiconductor devices, wherein a plurality of wafer boats each made of a refractory material and adapted to carry a predetermined number of wafers to be processed are sequentially fed into a furnace tube containing a high temperature, diffusion gas atmosphere and continuously transported at a predetermined speed through the furnace tube so that each wafer may have substantially the same thermal treatment and high productivity may be attained.

Abstract: An apparatus for automatically transferring semiconductor wafers is disclosed. Semiconductor wafers are loaded on a boat which is placed on a pair of first supporting bars. A pair of second supporting bars are driven by a motor to repeat circular motion between the first supporting bars. The second supporting bars, circularly moving in parallel with the first supporting bars, forwardly transfer the boat. The boat is kept uplifted over the first supporting bars during the forward transfer thereof. Repetition of the circular motion of the second supporting bars makes the automatic transfer of the semiconductor wafers to be heat-treated in a semiconductor manufacturing system.