3.1:Invited Paper: Oxide Versus LTPS TFTs for Active-Matrix Displays

ABSTRACTOxide-nitride-oxide (ONO) stacked films deposited by plasma enhanced chemical vapor deposition (PECVD) have been studied for use as the gate dielectric in active matrix displays. Good electrical properties were obtained for cadmium selenide thin film transistors (TFTs) with either ONO or single layer SiO2 gate insulation. However, the dielectric strength was up to twice as large for the ONO films. This improvement was observed with both Al and Cr electrodes.The individual oxide layers had compressive stress, while the individual nitride layers had tensile stress. When combined in an ONO structure, a net tensile stress of relatively low magnitude was obtained. Index of refraction and infrared absorption measurements indicated that the oxide films were oxygen deficient. Hydrogen incorporation was present for both the oxide and nitride films.

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Monocrystalline Si Films from Transfer Processes for Thin Film Devices

MRS Proceedings ◽

10.1557/proc-685-d2.1.1 ◽

2001 ◽

Vol 685 ◽

Cited By ~ 3

Author(s):

Ralf B. Bergmann ◽

Christopher Berge ◽

Titus J. Rinke ◽

Jürgen H. Werner

Keyword(s):

Thin Film ◽

Epitaxial Growth ◽

Defect Density ◽

Silicon On Insulator ◽

Active Matrix ◽

Plastic Substrates ◽

Light Point ◽

Single Host ◽

Active Matrix Displays ◽

Si Films

AbstractThe transfer of thin monocrystalline silicon films to foreign substrates is of great interest for a number of applications such as silicon on insulator devices, active matrix displays and thin film solar cells. We present a transfer approach for the fabrication of monocrystalline Si films on foreign substrates based on the formation ofquasi-monocrystallineSi-films. Our transfer approach is compatible with high temperature processing such as epitaxial growth at 1100°C, thermal oxidation and phosphorous diffusion. Reuse of Si host wafers is demonstrated by the subsequent epitaxial growth of three monocrystalline Si films on a single host wafer. Monocrystalline Si films with a thickness of 15 µm and a diameter of 3” are transferred to glass and flexible plastic substrates. The typical light point defect density in films transferred from virgin wafers ranges between 10 to 100 cm−2, while stacking fault and dislocation densities are ≤ 100 cm−2. The minority carrier diffusion length in the epitaxial Si films is around 50 µm.

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Organic Thin-Film-Transistors with High on/off Ratios

MRS Proceedings ◽

10.1557/proc-377-695 ◽

1995 ◽

Vol 377 ◽

Cited By ~ 2

Author(s):

L. Torsi ◽

A. Dodabalapur ◽

H. E. Katz ◽

A. J. Lovinger ◽

R. Ruel

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Switching Time ◽

Channel Length ◽

Organic Thin Film ◽

Field Effect Mobility ◽

Short Channel ◽

Active Matrix ◽

Current Voltage ◽

Active Matrix Displays

ABSTRACTIn this article a new procedure to obtain alpha-hexathienylene (α-6T) thin-film-transistors (TFTs) with on/off ratios in excess of one million is reported. This procedure involves subjecting the TFTs to rapid thermal annealing. Previously, high on/off ratios have been achieved with improved device design and better chemical synthesis of α-6T oligomers. High on/off ratios, along with a switching time of ∼ 10 μs, render α-6T TFTs potential candidates as switching devices in active matrix displays. The experimental current-voltage (I-V) characteristics of oc-6T TFTs with channel length L = 4μm are also presented and a measured field effect mobility of 0.02 cm2/V-s is extracted from these characteristics using an analytical model which we have developed for short-channel α-6T TFTs.

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