Diffusion furnace

The utility model discloses a diffusion furnace, which relates to the technical field of diffusion furnaces and comprises a reaction chamber, a quartz boat for containing silicon wafers is arranged in the reaction chamber, a first air outlet pipe and a second air outlet pipe are arranged on two sides of the quartz boat in the reaction chamber, a plurality of first air outlets distributed in an array are arranged on the first air outlet pipe, and a plurality of second air outlets distributed in an array are arranged on the second air outlet pipe. A spiral gas outlet pipe is arranged on the periphery of the silicon wafer in the reaction chamber, a plurality of third gas outlets are formed in the spiral gas outlet pipe, nitrogen is discharged through the first gas outlet pipe, boron trichloride is discharged through the second gas outlet pipe, and oxygen is discharged through the spiral gas outlet pipe. The oxygen and the boron trichloride are discharged separately, so that the pipeline is prevented from being b