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Mar 28th, 2013
WASAVI series “BGM300” TSV back grinding process measurement system
Lasertec Corporation today announced “BGM300”, a new WASAVI* series product that measures silicon wafer thicknesses and TSV depths prior to back grinding process of 3D semiconductor device production. Lasertec is planning to deliver an initial unit of BGM300 to a major device manufacturer.
Efforts are being made in the semiconductor industry to commercialize 3D integrated circuits that have multiple silicon chips vertically stacked for a further increase of density, process speed, and energy efficiency. The stacked chips are electrically interconnected by electrodes called Through Silicon Vias (“TSVs”). In production of 3D semiconductors with
BGM300 can also measure remaining silicon thickness (RST) over TSVs after grinding. BGM300 combines a newly developed IR optics with an interferometer used on Lasertec’s MPM series, which is acclaimed as an industry standard of phase shift measurement systems among photomask manufacturers and users. Since visible lights used by most commercially available measurement systems have limited penetration depths into wafers, they are not desirable for the pre-grinding measurement. conventional IR optics-based systems also have difficulty with TSV depth measurement due to spot size limitations.
Furnished with the proven and reliable interferometer and new IR optics, BGM300 has overcome the challenges associated with pre-grinding TSV depth measurement. Unlike indirect measurement methods such as scatterometry, BGM300 does not require
Lasertec has developed BGM300 in a joint effort with DISCO Corporation. Lasertec is proposing optimum solutions for back grinding process.
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