Atomic Layer Deposition of High-k Dielectrics and Selective Atomic Layer Deposition of HfO2 and TiO2

Physicist Julius Edgar Lilienfeld filed the first patent for a transistor in Canada in 1925, describing a device similar to a Field Effect Transistor or "FET" [1]. However, Lilienfeld did not publish any research articles about his devices, nor did his patent cite any examples of devices actually constructed. In 1934, German inventor Oskar Heil patented a similar device [2]. From 1942 Herbert Mataré experimented with so-called Duodiodes while working on a detector for a Doppler RADAR system. The dual diodes built by him had two separate but very close metal contacts on the semiconductor substrate. He discovered effects that could not be explained by two independently operating diodes and thus formed the basic idea for the later point contact transistor. In 1947, John Bardeen and Walter Brattain at AT&T's Bell Labs in the United States observed that when electrical contacts were applied to a crystal of germanium, the output power was larger than the input. Solid State Physics Group leader William Shockley saw the potential in this, and over the next few months worked to greatly expand the knowledge of semiconductors. The term transistor was coined by John R. Pierce [3]. According to physicist/historian Robert Arns, legal papers from the Bell Labs patent show that William Shockley and Gerald Pearson had built operational versions from Lilienfeld's patents, yet they never referenced this work in any of their later research papers or historical articles. The transistor is the key active component in practically all modern electronics, and is considered by many to be one of the greatest inventions of the twentieth century [4]. Its importance in today's society rests on its ability to be mass 2 produced using a highly automated process (semiconductor device fabrication) that achieves astonishingly low per-transistor costs

Selective atomic layer deposition of HfO2 on copper patterned silicon substrates

Selective atomic layer deposition (ALD) was performed on copper patterned silicon substrates to selectively deposit HfO2 film on silicon. The selectivity is based on differences of surface physics/chemistry rather than use of any molecular masking such as self-assembled monolayers. On silicon, the growth rate of HfO2 is 0.11 nm /cycle with no initial inhibition of film growth, while on copper no HfO2 deposition was observed up to at least 25 ALD cycles. The selective growth on silicon over copper at 25 ALD cycles provides a patterned film deposition at thicknesses of 2.8 nm HfO2 which is relevant to semiconductor nanofabrication. © 2010 American Institute of Physic

Atomic layer deposition and characterization of stoichiometric erbium oxide thin dielectrics on Si(1 0 0) using (CpMe)3Er precursor and ozone

Thin stoichiometric erbium oxide films were atomic layer deposited on p-type Si(100) substrates using tris(methylcyclopentadienyl)erbium and ozone. The film growth rate was found to be 0.12 ± 0.01 nm/cycle with an atomic layer deposition temperature window of 170-330 ºC. X-ray photoelectron spectral (XPS) analysis of the resulting Er2O3 films indicated the as-deposited films to be stoichiometric with no evidence of carbon contamination. Studies of post deposition annealing effects on resulting films and interfaces were done using Fourier transforms infrared spectroscopy, XPS, glancing incidence X-ray diffraction, and optical surface profilometry. As-deposited Er2O3 films were found to crystallize in the cubic structure with dominant (222) orientation; no erbium silicate was found at the interface. After annealing at 800 ºC in N2 for 5 min, a new XPS feature was found and it was assigned to the formation of erbium silicate. As the annealing temperature was increased, the interfacial erbium silicate content was found to increase in the temperature range studied

Phenazopyridine Cocrystal and Salts That Exhibit Enhanced Solubility and Stability

One phenazopyridine monohydrate (<b>1</b>·H₂O), one cocrystal of phenazopyridine with phthalimide (<b>2</b>), and three salts of phenazopyridine with benzoic acid (<b>3</b>), 4-hydroxyphenylacetic acid (<b>4</b>), and scaaharin (<b>5</b>) were synthesized, and their structures were determined by single crystal X-ray diffraction. The results of dissolution experiments indicate that the solubility of phenazopyridine can be enhanced after the formations of cocrystal and salts, in which the apparent solubility value of <b>5</b> is approximately 9 times as large as that of phenazopyridine in water, and the apparent solubility value of <b>4</b> is approximately 10 times as large as that of phenazopyridine hydrochloride (<b>1</b>·HCl) in 0.1 M HCl aqueous solution. The results of the stability study demonstrate that <b>2</b>–<b>5</b> are less hygroscopic than <b>1</b>·H₂O and <b>1</b>·HCl at both 85% and 98% RH

Comparison of Anatomical Parameters of the Parotid Gland Between Two Groups.

<p>Comparison of Anatomical Parameters of the Parotid Gland Between Two Groups.</p

Phenazopyridine Cocrystal and Salts That Exhibit Enhanced Solubility and Stability

One phenazopyridine monohydrate (<b>1</b>·H₂O), one cocrystal of phenazopyridine with phthalimide (<b>2</b>), and three salts of phenazopyridine with benzoic acid (<b>3</b>), 4-hydroxyphenylacetic acid (<b>4</b>), and scaaharin (<b>5</b>) were synthesized, and their structures were determined by single crystal X-ray diffraction. The results of dissolution experiments indicate that the solubility of phenazopyridine can be enhanced after the formations of cocrystal and salts, in which the apparent solubility value of <b>5</b> is approximately 9 times as large as that of phenazopyridine in water, and the apparent solubility value of <b>4</b> is approximately 10 times as large as that of phenazopyridine hydrochloride (<b>1</b>·HCl) in 0.1 M HCl aqueous solution. The results of the stability study demonstrate that <b>2</b>–<b>5</b> are less hygroscopic than <b>1</b>·H₂O and <b>1</b>·HCl at both 85% and 98% RH

Stabilization of Multimeric Enzymes against Heat Inactivation by Chitosan-<i>graft</i>-poly(<i>N</i>‑isopropylacrylamide) in Confined Spaces

The inactivation of multimeric enzymes is a more complicated process compared with that of monomeric enzymes. Stabilization of multimeric enzymes is regarded as a challenge with practical values in enzyme technology. Temperature-sensitive copolymer chitosan-<i>graft</i>- poly­(<i>N</i>-isopropylacrylamide) was synthesized and encapsulated with multimeric enzymes in the confined spaces constructed by the W/O microemulsion. In this way, the quaternary structures of multimeric enzymes are stabilized and the thermal stabilities of them are enhanced. The whole process was studied and discussed. This method, which works well for both glucose oxidase and catalase, can be developed as a general protection strategy for multimeric enzymes

Enantioselective Recognition and Separation of Racemic 1‑Phenylethanol by a Pair of 2D Chiral Coordination Polymers

A pair of 2D chiral coordination polymers were constructed through the self-assembly of a chiral metal-camphor-10-sulfonate salt and a bidentate linker, which show selective inclusion of <i>S</i> and <i>R</i> enantiomers of 1-phenylethanol respectively with an enantioselectivity of 9:1

Enantioselective Recognition and Separation of Racemic 1‑Phenylethanol by a Pair of 2D Chiral Coordination Polymers

A pair of 2D chiral coordination polymers were constructed through the self-assembly of a chiral metal-camphor-10-sulfonate salt and a bidentate linker, which show selective inclusion of <i>S</i> and <i>R</i> enantiomers of 1-phenylethanol respectively with an enantioselectivity of 9:1

Enantioselective Recognition and Separation of Racemic 1‑Phenylethanol by a Pair of 2D Chiral Coordination Polymers

A pair of 2D chiral coordination polymers were constructed through the self-assembly of a chiral metal-camphor-10-sulfonate salt and a bidentate linker, which show selective inclusion of <i>S</i> and <i>R</i> enantiomers of 1-phenylethanol respectively with an enantioselectivity of 9:1