Deep silicon etch is a critical process for manufacturing advanced chips that power a wide range of applications, including mobile devices, smart cars, and power grid and energy sectors. It is used to create larger and higher aspect ratio features such as through-silicon vias and trenches:
- Through-silicon vias (TSVs) are vertical structures that create electrical connections through a die or wafer. A key solution for advanced packaging, including heterogeneous integration, TSVs require excellent profile control, high within-wafer uniformity, and high productivity.
- Deep trench structures used in complementary metal-oxide-semiconductor (CMOS) image sensors face similar challenges, requiring smooth sidewall profiles with stringent taper control. Depth uniformity, CD uniformity, and mask selectivity are also essential.
- Large open area and high aspect ratio trench structures in advanced power devices poses additional challenges in controlling profile and uniformity cross wafer, as well as improving productivity for high volume manufacturing.
One approach for creating these structures is to quickly switch between etch and deposition steps during the manufacturing process, thereby carving the feature and layering material on the walls to protect them. However, this has become more challenging in recent years, due to increasingly higher aspect ratios, new materials being introduced, and tighter dimensional requirements in the manufacturing process.
In addition, chipmakers often have to choose between unwanted scallops – the features that result from alternating etch and deposition steps – and etch rate. Scallop size can be decreased, but at the expense of productivity needed for cost-efficient manufacturing.
Syndion’s enhanced source, chamber hardware, and process capabilities provides the precision solution chipmakers require to support deep silicon etch applications.