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New thin-film dielectrics and nanolaminates have been synthesized via aqueous-solution deposition of Hf and Zr sulfates, where facile gelation and vitrification of the precursor solution have been achieved without organic additives. X-ray reflectivity, imaging, and metal-insulator-metal capacitor performance reveal that smooth, atomically dense films are readily produced by spin coating and modest thermal treatment (T

The recent advance in soft solution processing of inorganic materials offers an exciting opportunity to develop large-area manufacturing technologies for inorganic thin-film transistors (TFTs). In this paper, we report our recent progress in fabricating CdS TFTs using chemical bath deposition (CBD) to deposit CdS channel layers. Device analysis of an enhancement-mode CdS metal-insulator-semiconductor field effect transistor (MISFET) with a field-effect mobility of ∼1.5 cm 2 V -1 s -1 and a threshold voltage of v T ∼ 14 V is reported here. An on-to-off ratio of ∼10 6 is achieved. This rather large drain current on-to-off ratio indicates that this device will function well as a switch. An examination of the CdS film morphology by scanning electron microscopy indicates that the films deposited by CBD and used for our current device fabrication are dominated by a particle sticking growth mechanism. This is supported by a real-time quartz crystal microbalance growth curve and atomic force microscopy characterizations of the particles formed in the CBD solution. A different bath condition for CBD was tested to obtain a dense CdS layer. A selected-area electron diffraction pattern indicates that the CdS thin film deposited by CBD has a hexagonal structure with an optical bandgap of 2.4 eV as determined by UV-Vis absorption.

A SnO2 transparent thin-film transistor (TTFT) is demonstrated. The SnO2 channel layer is deposited by RF magnetron sputtering and then rapid thermal annealed in O2 at 600°C. The TTFT is highly transparent, and enhancement-mode behaviour is achieved by employing a very thin channel layer (10–20 nm). Maximum field-effect mobilities of 0.8 cm2 V−1 s−1 and 2.0 cm2 V−1 s−1 are obtained for enhancement- and depletion-mode devices, respectively. The transparent nature and the large drain current on-to-off ratio of 105 associated with the enhancement-mode behaviour of these devices may prove useful for novel gas-sensor applications.

Transparent electronics is an embryonic technology whose objective is the realization of invisible electronic circuits. We have recently reported the fabrication of a novel n-channel transparent thin-film transistor (TTFT). [1] This ZnO-based TTFT is highly transparent and exhibits electrical characteristics that appear to be suitable for implementation as a transparent select-transistor in each pixel of an active-matrix liquid-crystal display. Moreover, the processing technology used to fabricate this device is relatively simple and appears to be compatible with inexpensive glass substrate technology. The objective of the work reported herein is to summarize some of our recent TTFT electrical performance results. Materials, processing, and device structure details related to these devices appear in future publications.