Journal
JOURNAL OF MANUFACTURING PROCESSES
Volume 88, Issue -, Pages 97-109Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.jmapro.2023.01.039
Keywords
Chemical mechanical polishing; Bipolar electrochemistry; Wireless photoelectrochemical mechanical; polishing; Material removal rate; Ultrasmooth surface; GaN
Categories
Ask authors/readers for more resources
An efficient wireless photoelectrochemical mechanical polishing (WPECMP) method was proposed based on the mechanism of bipolar photoelectrochemistry, which applies a wireless electric field to separate photogenerated electron-hole pairs during polishing. The WPECMP method enables wafers to achieve a damage-free surface/subsurface, with a lower surface roughness and higher surface flatness compared to the CMP technology.
Chemical mechanical polishing (CMP) remains the necessary polishing technology in chip manufacturing, but its applications on inert n-type gallium nitride (GaN) and carborundum (SiC) semiconductors are inefficient. Based on the mechanism of bipolar photoelectrochemistry, an efficient wireless photoelectrochemical mechanical polishing (WPECMP) method was proposed. The method applies a wireless electric field to the ultraviolet (UV) light-irradiated semiconductor wafer to separate photogenerated electron-hole pairs during polishing, rather than the traditional wire-connecting wafer to a power source. WPECMP is thus a universal polishing method for freestanding and semiconductor-on-insulator substrate wafers. The material removal rate (MRR) may reach similar to mu m h(-1) level because the unpaired holes oxidize the wafer to accelerate the material removal in the mechanical polishing process. An apparatus was devised to allow the wafer to alternate between oxidation and mechanical polishing, and the method was validated by finishing GaN wafers that are inert in CMP processing. The best MRR achieved 1.2 mu m h(-1), one order of magnetite higher than that of the CMP technology. The WPECMP method enables wafers to achieve a damage-free surface/subsurface, a surface roughness (Sa) of less than 0.082 nm in 5 x 5 mu m(2), and a surface flatness of less than 3.2 nm over 45 mm. The study opens a way to develop ultra-precision processing technologies with wireless electric field assistance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available