39‐4: TFT Integrated Microelectromechanical Shutter for Display Application

Abstract

Vertically translating prestressed spring supported microelectromechanical shutters can be used as digital spatial light modulators for high speed, efficient transmissive display applications. Prestressed MEMS shutters have been fabricated alongside top gate a-Si:H TFTs using a four mask TFT-MEMS process and active matrix driving has been demonstrated.

50.2: Invited Paper: Characterization of Co‐Fabricated Silicon TFT and MEMS Shutter Display

“…Sub-millisecond response times are highly desirable as they would be indispensable for fieldsequential color systems. Previously, we reported a surprisingly strong asymmetry of the switching behavior of directly addressed MEMS devices 8 . Those experiments demonstrated a collapse response time in the range of 500 µs and release times in the range of tens of milliseconds.…”

“…Using the optimized five mask manufacturing process, an initial 1.45 cm diagonal active matrix demonstrator with 48x72 pixels, each containing one amorphous silicon addressing TFT (W/L=20µm/5µm) in the pixel area of 220µm x 130 µm, had previously been demonstrated 8 . Figure 7 shows a new 6 cm diagonal AM-MEMS display demonstrator having 320x240 pixels of 150µm x 150µm each.…”

High‐performance MEMS shutter display with metal‐oxide thin‐film transistors and optimized MEMS element

“…So unlike active matrix liquid crystal displays where the bottom gate is used to protect the channel from the backlight, the MEMS shutter display requires top gate structures. Co-fabrication of prestressed MEMS elements with top gate a-Si:H TFTs had been presented before [5][6][7] by our group.…”

“…Several optimizations had been performed before and the "P" structure had been proposed where the bending radius around 150 μm with actuation voltage around 35 V had been achieved. 6 Decreasing the bending radius without increasing the actuation voltage will not only increase the lightoutcoupling but also open the possibility to implement higher resolution (>250 ppi). For structures with lower bending radius ($60-70 μm), an "L"-shaped structure (Figure 5) is more advantageous because much light can be outcoupled through direct transmission.…”

“…Though several attempts at commercialization had failed before, [2][3][4] our group has successfully demonstrated highly efficient and robust vertically translating MEMS shutter display for transmissive display application. [5][6][7] The vertically translated MEMS shutter display technology has been further improved by integrating metaloxide thin-film transistors (TFTs) and optimizing the structure for a high-resolution and highly efficient display.…”