Apparatus for diffusion into semiconductor wafers
AssigneeHitachi, Ltd.
InventorsKeizo Inaniwa, Noboru Ryugo
Life of this patent
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Abstract
In diffusing an impurity into semiconductor wafers within a silica tube by the use of a heating furnace, a method of diffusion involves the following steps: the semiconductor wafers are inserted into the tube from an inlet thereof, the inlet is sealed by a cap, the interior of the tube is placed under vacuum, and an atmosphere of the impurity is formed. Since, at heating, the tube is closed and no inert gas is fed thereinto, the temperature distribution within the tube is held uniform, and hence the quantities of impurity introduction into the semiconductor wafers are not varied.
Claims19
An apparatus for treating semiconductor wafers comprising an elongated furnace tube having first and second openings, detachable closure means provided at said first opening for furnace tube having first and second openings, detachable closure means provided at said first opening for sealing said first opening, first supporting means for placing substantially erect semiconductor wafers into said tube to extend serially in a group along the axis of said tube and for arranging at least one boron nitride source substantially vertically relative to said semiconductor wafers in said tube and spaced from, but adjacent to, said semiconductor wafers without contacting the inner surface of said tube, means connected to said second opening for reducing pressure in said tube below atmospheric pressure, and means for heating said semiconductor wafers and boron nitride source so as to deposit boron impurity on surfaces of said semiconductor wafers from the boron nitride source under the pressure-reduced state, wherein said boron nitride source comprises at least one boron nitride wafer.
An apparatus for diffusing boron impurity into semiconductor wafers which comprise an elongated sealing said first opening, first supporting means for erecting semiconductor wafers in said tube along the length of said tube, second supporting means for arranging at least one impurity source containing a conductivity type determining impurity perpendicular to said semiconductor wafers in said tube spaced from, but adjacent to, the edges of said semiconductor wafers without contacting said tube, means connected to said second opening for reducing pressure in said tube below atmospheric pressure, and heating means provided adjacent said tube for heating said semiconductor wafers and impurity source so as to deposit the impurity on surfaces of said semiconductor wafers under the pressure-reduced state.
An apparatus for diffusing boron impurity into semiconductor wafers which comprises an elongated furnace tube having first and second openings, detachable closure means provided at said first opening for sealing said first opening, first supporting means for placing substantially erect semiconductor wafers into said tube to extend serially in a group along the axis of said tube, second supporting means for arranging at least one boron nitride source substantially vertically to said semiconductor wafers in said tube and spaced from, but adjacent to, the edges of said semiconductor wafers without contacting the inner surface of said tube, means connected to said second opening for reducing pressure in said tube below atmospheric pressure, and means for heating said semiconductor wafers and boron nitride source so as to deposit boron impurity on surfaces of said semiconductor wafer from the boron nitride source under the pressure-reduced state.
Dependencies are inferred from the claim text.