The invention relates to a method for implementing aluminum 
diffusion on a 
silicon wafer. The method includes making a texture surface on the front surface of the 
silicon wafer, and 
coating a 
silicon oxide isolating membrane on the back surface of the silicon 
wafer; implanting ions, in other words, selecting 
solid AlCl<3> as an aluminum 
diffusion source, heating the 
solid aluminum source under a high-vacuum condition so that the 
solid aluminum source sublimates at the temperature of 120-170 DEG C, loading the solid aluminum source into a source region of a filament of an 
ion implanter by using 
argon as a carrier, enabling the solid aluminum source to be collided with electrons generated by the filament to form the charged aluminum ions, accelerating the charged aluminum ions by 
high voltage, screening the ions by a magnetic analyzer, and further 
doping aluminum impurities into the silicon wafer; cleaning the silicon wafer; dehydrating the cleaned silicon wafer by 
anhydrous ethanol and placing the silicon wafer in a 
drying oven at the temperature of 100-110 DEG C to dry the silicon wafer; and placing the dried silicon wafer in a 
diffusion furnace, heating the diffusion furnace so that the temperature of the diffusion furnace is 1250-1260 DEG C, and keeping the temperature constant for 10-12 hours. The method has the advantages that the total 
doping contents for 
ion implantation are accurately controlled, the precision and the 
repeatability of a diffusion process are improved, and a large-area uniform 
doping effect is realized.