The semiconductor industry’s rule on wafer flatness is getting high year after year. That’s because the demand for thinner and smaller gadgets is growing each day. Thus, ultra flat wafers are born. Ultra-flat wafers are like you regular wafers, except they’re ultra-thin. In this article, we will discuss what you need to know about the grinding-based method of manufacturing ultra flat wafers.
To achieve ultra flat wafers, wafers need to go through the wafer grinding process. It involves diamond cup wheels. Traditional grinding uses a porous ceramic chuck to vacuum a wafer in place and grind it. At the same time, soft-pad grinding uses a punctured soft pad between the wafer and the ceramic chuck. During wafer grinding, the diamond cup wheel and the wafer spin about their rotation axes simultaneously. The wheel is then brought near the wafer along its axis.
Regular wafers go through lapping, etching, and rough polishing. Unfortunately, the lapping process can cause subsurface damage and scratches on the wafer. Wafer grinding replaces the lapping, etching, and grinding polishing processes. This helps improve the quality of the ultra flat wafers.
This grinding-based method does not use any wet etching process. It also only uses minimal polishing. Because of this, manufacturers produce flatter wafers at a lower cost.
Because the grinding process is automatic, it is more efficient at grinding wafers. This automation results in lower labor costs and fewer chipped wafers.