AMLCD on plastic substrates

: A review of the advantages of plastic substrates for AMLCD shows that the initial market is likely to be in the ‘hand held’ portable computing area. There, the combination of ruggedness, low weight and high performance will become essential. Work on top gate TFT devices made using the industry standard PECVD deposition of a-Si and SiN shows that growth at temperatures suitable for poly-ethyl sulphone (PES) substrates can lead to excellent device characteristics. A key issues with PES is the dimensional instability during etching between lithography steps. A TFT ‘finger’ design allows for dimensional changes and provides acceptable display performance.