Fabricating method of fin field effect transistor (FinFET)

A fabricating method of a fin field effect transistor (FinFET), comprising:

• providing a substrate;
• forming a plurality of fin structures by removing a portion of the substrate;
• depositing a dielectric layer on the substrate filling between the fin structures;
• forming a plurality of recesses to reveal a portion of the fin structure by removing a first portion of the dielectric layer;
• performing a cleaning process on the fin structures and the dielectric layer using a cleaning solution selected from one of a first solution and a second solution, wherein the first solution consists of dilute hydrogen fluoride and hydrogen peroxide and the second solution consists of dilute hydrogen fluoride and ozonated deionized water;
• forming a gate structure on the fin structures, wherein an extending direction of the gate structure is perpendicular to an extending direction of the fin structures;
• and
• forming a source/drain structure on the substrate at two lateral sides of the gate structure.