Electronic Devices advanced microelectronic

In the past decade, microfabrication methods developed in the microelectronic industry have led to new opportunities for device research and development involving chemically sensitive electronic structures. In 1980, this subject was reviewed in depth at a NATO Advanced Study Institute (1). Over the last five years, there have been three international conferences 2-k), devoted to sensors with a strong emphasis on chemical sensors as well as a number of national and specialized meetings on the subject (5,6). In this paper, some recent developments that will have long term consequences on the study of chemically sensitive electronic devices will be reviewed. To simplify the discussion, the topics are divided into the following categories ... 

The design of the most advanced microelectronic devices now requires with sub-half micron dimensions. Photo, electron beam and x-ray lithographies are all candidates for patterning at such resolution. Resist resolution, along with relief image wall profiles and contrast must be improved and controlled in order for the fabrication of such devices to become practical. 

Polyimides have been widely used in the advanced microelectronics industry such as passivation or stress-relief layers for high-density electronic packaging, interlayer dielectric layers for wafer-level semiconductor fabrication, or alignment layers for liquid crystals in advanced liquid crystal display devices (LCDs) owing to their outstanding thermal, mechanical and good insulation properties with low dielectric constant, good adhesion to common substrates and superior chemical... 

The fabrication of microelectronic and photonic components involves long sequences of batch chemical processes. The manufacture of advanced microstructures can involve more than 200 process steps and take from 2 to 6 weeks for completion. The ultimate measure of success is the performance of the final circuits. The devices are highly sensitive to process variations and are difficult, if not impossible, to repair if a particular chemical process step should fail. Furthermore, because of intense competition and rapidly evolving technology, the development time from layout to final product must be short. Therefore, process control of electronic materials processing holds considerable interest [30, 31]. The process control issues involve three levels ... 

The special properties of nanomaterials, such as those currently used as the conductive "pigment" in conductive inkjet inks, will be exploited more and more in advanced second-generation products. New inks will be developed to print additional electronic functionalities such as resistors, capacitors, and semiconductors, thereby enabling inkjet printing of complete electronic components and devices. Inkjet s capability to layer materials and build 3D structures will be further developed for microelectronics applications. These efforts have already been initiated in universities, research institutes, and commercial entities — in the large established ink companies as well as smaller startups financed by joint VC and government funding. 

Our technologically advanced way of life would not be possible without the semiconductor industry. The first semiconductor device known as a transistor was discovered at Bell Labs in the late 1940s, and was widely used shortly thereafter for radio electronics. Today, transistors are still pervasive in every microelectronic component such as CD/DVD players, cellular phones, modes of transportation (e.g., planes, automobiles, etc.), and computers. In fact, the dual-core chips released by Intel in early 2006 feature over 1.7 billion transistors - all on a surface that is smaller than a postage stamp ... 

The electronic structures of the cooperative J-T phases of all three group IVB transition metal oxides are always referenced to ideal structures, cubic rutile for Ti02, and cubic Cap2 for HfOi and ZrOa. This approach parallels the seminal electronic structure calculations of the Robertson group at the University of Cambridge in which conduction band offset energies between Si and these TM oxides have been addressed in the context of replacement or alternative dielectrics for Si02 in advanced Si microelectronic devices [1,10]. 

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