The invention discloses a preparation method of a
silicon-
phosphorus alloy, and relates to the technical field of
semiconductor materials. The method comprises the following specific steps: cleaning and
drying an appliance; respectively weighing a
silicon elementary substance and a red
phosphorus elementary substance according to the weight percentage; putting the
silicon elementary substance and the red
phosphorus elementary substance into the appliance, vacuumizing a
quartz tube by using vacuumizing equipment, and then performing
vacuum tube sealing on the
quartz tube; putting the
quartz tube into a high-pressure horizontal furnace, enabling the silicon elementary substance to be positioned in a high-temperature area of the high-pressure horizontal furnace, enabling the red phosphorus elementary substance to be positioned in the low-temperature area of the high-pressure horizontal furnace, and enabling the quartz block to be positioned between the high-temperature area and the low-temperature area of the high-pressure horizontal furnace; placing temperature thermocouples at two ends of the quartz boat respectively; performing variable-
temperature treatment on the quartz tube; controlling internal and
external pressure balance of the quartz tube; and synthesizing
alloy,
cutting the quartz tube, and taking out the
alloy material. The method has the advantages that alloy preparation is carried out in the closed quartz tube so as to avoid external
pollution, further material purification is carried out by using a
directional solidification technology, and the purity of the synthesized silicon-phosphorus alloy is high.