Channel filling method, STI structure and chip

The invention belongs to the technical field of semiconductor technologies, and particularly relates to a channel filling method, an STI structure and a chip. A hydrogen treatment H2T (H2 Treating) step, namely a third filling step (300), is added between an in-situ water vapor generation ISSG (In Situ Stem Generation) process and a high aspect ratio process (HARP) deposition process, and the content of hydrogen element H in a target channel (333) of a workpiece (001) from a channel opening to the bottom of the channel is adjusted according to a preset gradient; the hydrogen H content of the target channel (333) is gradually increased from the channel opening to the channel bottom, so that the corresponding HARP deposition rate is gradually reduced from the channel opening to the channel bottom; therefore, the sealing phenomenon of a delay structure of a suspended OHG (Over-HanG) part is reduced, and the effect of filling a GPF (Gap Film) in a channel is improved; the limitation that the inclination angle of