Backside Etching Solution (Spin-D, Spin-E, Spin-BT…)

Backside Etching

As semiconductor devices move towards higher precision and the trend of being "compact and lightweight," backside etching has gradually replaced traditional mechanical backside grinding. In addition to reducing silicon wafer stress and minimizing defects, it effectively removes impurities from the backside, preventing contamination of the front-side processing.
Since the backside surface often includes various materials such as silicon dioxide, polysilicon, organic substances, metals, silicon nitride, and polysilicon, the wet backside etching solution also contains a mixture of several inorganic acids, including H₃PO₄, HNO₃, H₂SO₄, and HF. This composition is necessary to effectively remove the complex structure of the backside layer.

Detailed introduction

Some defects caused by the backside grinding of silicon wafers include: grinding damage layers, crystal defects, and micro-cracks. The rotational wet etching process can effectively reduce mechanical stress on the backside of the wafer, minimizing surface damage (sub-surface damage layer) caused by the grinding process, thus improving the structural integrity of the wafer.

Additionally, when backside metal deposition is required after grinding to increase adhesion, special reagents (spin-etching) can be added to the etching solution. This creates a micro-roughened surface on the wafer, which enhances the adhesion of the metal deposition.

Packaging type：200L drum

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