SILICON FINE PARTICLES AND METHOD FOR PRODUCING SAME

Provided are silicon fine particles that are effectively prevented from being oxidized and have a crystallite diameter close to that of an amorphous substance. The silicon fine particles of the present invention have an average diameter of primary particles of 30 to 900 nm, a crystallite diameter of less than 10 nm, a chlorine concentration of 1 to 10% by mass, and a ratio (Co/S) of an oxygen concentration (Co: % by mass) to a specific surface area (S: m2/g) of less than 0.05. The method for producing silicon fine particles of the present invention includes: heating a gas containing trichlorosilane to a temperature of 600 to 950° C. in a reactor and thermally decomposing the trichlorosilane to produce a silicon fine particle precursor containing chlorine, then collecting the silicon fine particle precursor, and then heating and dechlorinating the collected silicon fine particle precursor at a temperature of 750 to 900° C. under supply of an inert gas or under reduced pressure.