Roll-to-roll Semiconductor Manufacturing facility

Our group has developed technologies to fabricate single-crystalline-like semiconductor thin films on inexpensive, flexible substrates. These semiconductors have been used to demonstrate thin film transistors with 100-fold higher mobility than those currently used in flexible electronic devices. Also, they have been used to demonstrate thin film III-V semiconductor photovoltaics to achieve high efficiency solar cells at low cost. We have established a complete range of roll-to-roll thin film deposition systems for semiconductor manufacturing, including two ion beam assisted deposition (IBAD), three magnetron sputtering and one e-beam evaporation systems (Figure 6).

Figure 6. Several roll-to-roll thin film deposition tools for semiconductor manufacturing

Roll-to-roll semiconductor processing, device manufacturing and metrology are conducted in our 13,000 sq.ft. Semiconductor Device Fabrication Laboratory (building 15) at the UH Energy Research Park. The Semiconductor Device Fabrication Laboratory consists of a class 10,000 cleanroom, a device fabrication area and a metrology area. The Laboratory is equipped with facilities to safely handle several toxic and pyrophoric gases (Figure 7) that are used in metal organic chemical vapor deposition (MOCVD) and plasma enhanced chemical vapor deposition (PECVD) processes for semiconductor manufacturing. Low pressure gas cylinders are used for arsine, phosphine and germane delivery to further enable safe operation. Being a self-contained facility off-campus with specialized gas handling in a secured building and its own in-house safety manager, our Semiconductor Device Fabrication laboratory provides a unique facility for UH researchers, not feasible elsewhere on campus.

Figure 7. Facilities at or Semiconductor Device Fabrication Laboratory to safely handle pyrophoric gases and toxic gases for semiconductor manufacturing

We have established a novel tool for roll-to-roll MOCVD of III-V thin films in the cleanroom area in the Semiconductor Device Fabrication Laboratory (Figure 8). Some of the key features of this tool include dual reactors, one for roll-to-roll processing of 100 m long, 50 mm wide flexible substrates and another for 50 mm diameter wafers, delivery of six metal organic and six hydrides precursors, deposition temperature capability up to 1300°C, 600 W plasma sources, and all necessary features for safe operation. This tool is very likely the first roll-to-roll compound semiconductor MOCVD system ever to be built in the world.

Figure 8. Roll-to-roll III-V compound semiconductor MOCVD tool at our facility

Two Plasma Enhanced Chemical Vapor Deposition (PECVD) tools, one for epitaxial germanium and silicon deposition (Figure 9) and another for dielectric deposition are present in a class 10,000 cleanroom along with the MOCVD tool. Complete semiconductor device fabrication equipment including sputter, e-beam and thermal evaporation systems and lithography tools are available in the device fabrication area. Photolithographic tools for semiconductor device fabrication are present in a separate device fabrication area (Figure 9).

Figure 9. (Left) PECVD tool for silicon, germanium and other semiconductor manufacturing (Right) Device fabrication tools including mask aligner for photolithography.