System and method of thinning wafer substrate

A wafer processing system comprising:

• a processing tool comprising:
• a rotation shaft;
• a rotation head fixed to a lower end of the rotation shaft and defining a recess at a bottom surface of the rotation head;
• a grinding member positioned on the bottom surface of the rotation head and surrounding the recess;
• a first electrode surrounding the rotation shaft and electrically connected to the rotation head;
• and
• a fluid supply line formed within the rotation shaft and the rotation head and configured to supply an electrolyte to the recess;
• a holding module configured to hold a wafer substrate and comprising a second electrode;
• an actuator assembly configured to drive a rotation of the processing tool;
• and
• a power supply module configured to apply an electric current to the first and the second electrodes.

A wafer processing method, comprising:

• loading a wafer substrate on a holding module;
• contacting a grinding member with a surface of the wafer substrate, wherein the grinding member is arranged around a recess;
• applying an electric current to the wafer substrate and the grinding member and supplying an electrolyte into the recess so as to form an oxide layer on the surface of the wafer substrate;
• performing a grinding process by rotating the grinding member;
• and
• adjusting the movement of the grinding member or the supply of the electrolyte when a monitored parameter that is associated with thickness of the oxide layer is not within a range of a preset value.