Method to accurately control the manufacturing of high performance photodiode

The present invention provides a method to accurately control the manufacturing of high performance photodiode, which comprises providing a substrate; form a hard mask layer with a specific pattern on this substrate; etch this substrate without being covered by this hard mask layer, and form a shallow trench; grow a liner thermal oxide layer in this shallow trench by thermal oxidation method; apply a first thermal annealing process; define an n-well region in this shallow trench; implant this n-type well region; apply a second thermal annealing process, photodiodes which meet the requirement of various applications can be manufactured by adjusting the gradient of junction doping concentration according to this manufacturing method, and which won't affect the characteristics of the logic devices. Also, this method is compatible to the standard logic device process. In addition, the junction leakage defect can be improved by applying the thermal annealing process to the n-type well of photodiode.