Multilayer Processing

Semiconductor suppliers are constantly challenged as the semiconductor industry is one that evolves very rapidly. Throughout the years, technological advancements have led to a regular decrease in the size of chips, meaning that semiconductor suppliers have had to develop solutions to shrink feature sizes due to the smaller surface areas.

While these smaller chips allow for increased performance abilities, they aren’t without their downfalls. The small sizes of the features often affect the photoresists, causing such problems as pattern collapse and smaller processing windows. These may seem like significant issues, but they have been rather easily countered. Semiconductor suppliers and others in the industry have started to use thinner photoresists ranging between only 60 nm and 100 nm. These thin photoresists allow the smaller chips to avoid pattern collapse and actually perform at higher levels, which is what they were initially designed to do.

With thin photoresists, however, another issue presents itself to the semiconductor suppliers. Thinner photoresists decrease the etch budget when applying the pattern to a substrate, meaning a solution must be found to properly apply the pattern. For this, the industry has turned to multilayer processing. This process takes the thin photoresist and combines it with an inorganic hardmask, which is an essential material for effectively applying the pattern using a multilayer stack. The photoresist and hardmask are applied using one of two multilayer stack methods: Chemical Vapor Deposition (CVD) or Spin Coating.

Both methods rely on the highly inorganic material of the hardmask, which actually requires thinner photoresists. This inorganic material leads to better performance levels, including higher plasma etching speeds and pattern resolutions. To work most effectively, the hardmask layer must also contain high levels of carbon as it is essential for quality etching on inorganic substrates.

While both CVD and spin coating are great methods used regularly by the semiconductor industry, spin coating is known as the easier process of the two. CVD requires each wafer to be transferred to another module while spin coating takes the whole multilayer stack and places it in the coating module at once. Both processes work well and are up to the preference of the semiconductor manufacturer.

No matter which multilayer process you choose, you can benefit from increased production rates and quality as well as cost reduction. If you are interested in multilayer processing, Shin-Etsu MicroSi has high quality semiconductor materials for your operations. For more information on multilayer processing and the specialty products required, please call Shin-Etsu MicroSi, a top semiconductor supplier, at (480) 893-8898 or contact us online today.