Manufacturing method for n-polar gan transistor structure and semiconductor structure

A fabrication method of an N-polar GaN transistor structure, comprising steps of:

• depositing a buffer layer on one side of a structural substrate;
• depositing an etching-blocking barrier layer on a side of the buffer layer away from the structural substrate;
• depositing an epitaxial functional layer of an upside-down N-polar transistor on a side of the etching-blocking barrier layer away from the structural substrate, such that a side of the epitaxial functional layer away from the structural substrate is a Ga-polar surface;
• forming by bonding a support substrate on the side of the epitaxial functional layer away from the structural substrate;
• removing the structural substrate to make the buffer layer exposed;
• removing the buffer layer to make the etching-blocking barrier layer exposed;
• and
• manufacturing a source electrode, a drain electrode and a gate electrode on a side of the epitaxial functional layer away from the support substrate, so as to form an N-polar GaN transistor.