Tim Koch

Review Paper: A critical review of the present and future prospects for electronic paper

Abstract— The commercial success of monochrome electronic paper (e-Paper) is now propelling the development of next-generation flexible, video, and color e-Paper products. Unlike the early battles in the 1980s and 1990s between transmissive and emissive display technologies, there is a extraordinary diversity of technologies vying to become the next generation of e-Paper. A critical review of all major e-Paper technologies, including a technical breakdown of the performance limitations based on device physics and commentary on possible future breakthroughs, is presented. In addition, the visual requirements for color e-Paper are provided and compared to standards used in conventional print. It is concluded that researchers have much work remaining in order to bridge the significant gap between reflective electronic displays and print-on-paper.

Arsenic out‐diffusion during TiSi2 formation

The behavior of implanted As atoms during high‐temperature (800–900 °C) TiSi2 formation was investigated by helium backscattering. A significant As loss was observed during TiSi2 formation by vacuum furnace annealing. The main factors influencing the As loss were the initial As profiles and Ti film thickness. Most of the As loss was caused by rapid As out‐diffusion through the TiSi2 layer; the remaining As atoms were only observed in the Si substrate after TiSi2 formation. As long as the As distribution was deeper than the TiSi2 layer, the loss of As atoms was kept to a minimum. Careful selection of the As implantation energy and the Ti film thickness can achieve high As concentration at the TiSi2/Si interface.

Dopant redistribution during titanium silicide formation

For advanced metal‐oxide‐semiconductor structures it is highly desirable to have a self‐aligned silicide structure on source and drain regions as well as on the gate in order to simplify lithography while reducing parasitic resistances. The reproducible formation of metal silicides on highly doped n+ and p+ regions with shallow junctions is required for those structures. Therefore, it is essential to understand the dopant behavior, silicide phase formation, and grain growth during high‐temperature annealing. Titanium silicides were formed on arsenic and boron difluoride implanted and annealed Si substrates. Arsenic atoms showed a significant redistribution and loss during titanium silicide formation. Arsenic atoms diffused out of the silicide surface with an activation energy of 0.95 eV. Boron atoms segregated to the silicide surface, and some boron atoms were lost from the surface; on the other hand, fluorine atoms were retained in the silicide layer. After prolonged 900 °C annealing, the thin titanium d...

A Bond Failure Mechanism

Intermittent continuity failures of P-DIP parts were found to be the result of wire bond failures induced by stresses associated with the assembly process. The bond failures were characterized by cracking of the underlying pad structure. It was found that silicon nodule precipitates from the aluminum metallization in the pad acted as points of high stress during the bonding of gold to the pad regions. By altering the bonding parameters and the underlying pad structure, failure of the bonds could be prevented.

21.4: Zinc Indium Oxide Thin-Film Transistors for Active-Matrix Display Backplane

We report on the development of low-temperature gate dielectric materials for zinc indium oxide (ZIO) thin-film transistors (TFTs). Several films, including ALD HfO2 and PECVD SiNx (deposited at 175°C and 150°C, respectively), yield good TFT performance. Bias stress-induced threshold shift for HfO2 is quite small, however does not follow conventional trends associated with hydrogenated amorphous Si (a-Si:H) TFTs; PECVD SiNx conversely, shows bias stress characteristics that conform reasonably to a model appropriate for a-Si:H devices.

69.4: Novel Flexible Reflective Color Media Integrated with Transparent Oxide TFT Backplane

A novel architecture and proprietary electrically addressable inks have been developed to provide disruptive, print-like full color reflective digital media solutions based on an electrokinetic technology platform. The thin, flexible, low-power, reflective electronic media is fabricated with a new roll-to-roll manufacturing platform. Here we demonstrate the integration of this media with multi-component oxide (MCO) thin-film transistor (TFT) backplane for an active matrix reflective electronic display.

Novel flexible reflective color media with electronic inks

A novel architecture and proprietary electronic inks were developed to provide disruptive digital-media solutions based on an electrokinetic technology platform. The flexible reflective electronic media (eMedia) was fabricated by imprinting three-dimensional microscale structures with a roll-to-roll manufacturing platform. The HP technologies enable the required attributes for eMedia, such as low power, transparency, print-quality color, continuous levels of gray, and low-cost scalability. Pixelation was also demonstrated by integrating with the prototype oxide thin-film transistor backplane, and the system architecture was further developed by stacking primary-colorant layers for color reflective-display application. The innovations described in this paper are currently being developed further for the eSkins, eSignage, and ePaper applications.

Roll-to-roll fabrication and metastability in metal oxide transistors

A roll-to-roll process is used to fabricate amorphous silicon and amorphous multicomponent oxide (MCO) transistors on flexible substrates using self aligned imprint lithography (SAIL). SAIL solves the layer to layer alignment problem. The imprint lithography patterned MCO transistors had a mobility of 15 cm2V-1 sec-1 and an on-off ratio of 107. Full display arrays with data, gate, hold capacitors and cross-overs were patterned using SAIL technology. Studies of stability of the MCO transistors indicate the importance of controlling O vacancies in the material particularly the back channel. Devices subjected to -10V gate bias stress at 60C under illumination exhibited behavior consistent with state creation in the upper and lower half of the gap near the back channel interface possibly associated with O vacancy formation.

58.3: Fabrication of Zinc Tin Oxide TFTs by Self-Aligned Imprint Lithography (SAIL) on Flexible Substrates

Zinc tin oxide (ZTO) thin-film transistors (TFTs) provide attractive performance and are suitable for low-temperature processes compatible with flexible “plastic” substrates. We report our progress in integrating ZTO into our SAIL process to produce high-performance TFT on flexible substrates.

49.5L: Late-News Paper: Roll-To-Roll Manufacturing of Electronic Skins

A new roll-to-roll manufacturing platform has been developed that enables the fabrication of durable and flexible electronics. Here we present this platform capability and its application to create thin, conformable electronic skins that can change their appearance upon application of low-power electronic signals.