Ultra Flat Wafers | Wafer Thinning Techniques

The demand for ultra flat wafers has increased as the demand for slimmer and handier electronic devices has also increased. Thus, wafer manufacturers have developed various techniques to achieve the desired wafer flatness. If you’re wondering how ultra-flat wafers are made possible, here are some wafer thinning techniques used for ultra flat wafers:

Mechanical Grinding

Mechanical grinding is considered to be the most common technique because of its high thinning rate. It is a two-step process which involves coarse grinding and fine grinding. Fine grinding is crucial to get rid of the damage and surface irregularity brought about by the coarse grinding step. The damages produced by this technique is examined through x-ray topography and interference contrast microscopy. The leftover defects put force on the thinned wafers which results in broken wafers and additional bow, especially during handling and further processing. That is why additional thinning is crucial to remove the layer with flaws.

CMP or Chemical Mechanical Planarization

This technique is used to polish silicon wafers. CMP produces ultra-flat surfaces and low total thickness variation standards. The thinning rate of CMP is low compared to the mechanical grinding technique. CMP is practical for large quantity application for thick wafers.

Dry Etching or Atmospheric Downstream Plasma (ADP) Dry Chemical Etching (DCE)

This is considered to be a new method for wafer thinning. Traditional dry etch processing uses plasma which contains fluorine and chlorine but the new method involves Ar/ CF-containing plasma.

Wet Chemical Etching

This common thinning technique involves etching one side of the wafer. Spin etching is one of the approaches that involves a thin surge of etching agent flowing systematically on top of the rotating wafer. For silicon, common etching agents are HF and HNO3.

Are you Looking for Ultra Flat Wafers?

Not all ultra flat wafers are created equal. Make sure to get high-quality wafers at a reasonable price from Wafer World. We are proud to serve our clients for more than 20 years. We have provided them nothing but the best products in the market- paired with excellent customer service. Call us today for any inquiry or purchase wafers online!