ARSENIC DIFFUSION AGENT AND MANUFACTURE THEREOF

PURPOSE:To decelerate the dissociation rate when arsenic is diffused on a silicon wafer for making the repeated application feasible by a method wherein the title arsenic diffusion agent is enabled to be formed in an arbitrary shape while reinforcing the structure so as to facilitate the industrial processing thereof by crystallizing the silicon arsenic in a ceramics porous structure using silicon as the skelton thereof. CONSTITUTION:In order to manufacture an arsenic diffusion agent, a porous structured body 4 formed of baked powder comprising silicon nitride, silicon carbide, silicon dioxide etc., manufactured in separate furnaces in proper shape is put away in a crucible 2 and after filling up the peripheral parts with silicon arsenide 5, an arsenic sealing up agent 6 is added to the upper part of the crucible 2. Next, when the temperature in the crucible 2 is raised to the level at 1090-1300 deg.C exceeding the melting point of the silicon arsenic and simultaneously a reactor is pressurized at the level exceeding 3 up to 80 atmospheric pressure, the silicon arsenide is melted down entering into the pores of the porous structured body 4 so as to fill the pores. Accordingly, if the heating process is stopped at this time and restored to atmospheric pressure after quenching at room temperature, the title arsenic diffusion agent wherein the silicon arsenide is evenly crystallized in the porous structure body 4 can be manufactured.