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Many researchers have studied the noise properties of optical amplifiers and have shown that all nonlinear optical amplifiers introduce noise into the amplified beam.1 In our research, we have conducted a theoretical and experimental investigation of the quantum noise generated by a phase-conjugate mirror (PCM) obtained using four-wave mixing in potassium vapor. An ideal PCM will generate light that exhibits excess quantum noise that is inherent to the phase conjugation process.2 Additional noise can be introduced as a result of fluctuations (e.g., collisions) in the nonlinear medium, as has been predicted for the nonlinear process of two-beam coupling in an atomic vapor.3 These sources of noise determine the fundamental limit on the smallest signal that can be phase-conjugated.

Studies of the growth of crystals of energetic materials under conditions of high acceleration in an ultracentrifuge are reported. When a saturated solution is accelerated in an ultracentrifuge, the solute molecules move individually through the solvent molecules to form a crystal at the outer edge of the tube if the solute is more dense than the solvent. Since there is no evaporation or temperature variation, convection currents caused by simultaneous movement of solvent and solute are minimized and crystal defects are potentially minimized. Crystal growth is controlled by the g-level of the acceleration. In addition, solution inclusions and bubbles migrate out of the saturated solution as a result of the pressure gradient induced by the g-force. We present results of TNT, RDX, and TNAZ grown at high g from various solutions.

Studies of the growth of crystals of energetic materials under conditions of high acceleration are reported. This new way of growing crystals of energetic materials by using a concentration gradient is different than the usual procedure of crystal growth by solvent evaporation at constant temperature or by temperature variation with slow cooling. When a solution is accelerated in an ultracentrifuge, the solute molecules concentrate at the outer edge of the tube if the solute is more dense than the solvent. If the solution is initially saturated, then the solution at the outer edge of the tube becomes supersaturated and crystal growth can occur. Results are presented for growth of TNT and RDX crystals at high g in an ultracentrifuge using no seed crystals for most of the samples.

This commemorative issue is graciously edited by Guest Editor Larry Nagel, with advice and input from Prof. David Hodges. In this issue, we are proud to feature original articles about the origin and impact of SPICE. We hope that you will enjoy reading all of these articles, and we are grateful to our expert authors for writing the articles that appear in this issue. I thank Dr. Nagel for serving as guest editor for this issue and Prof. Hodges for his advice and coordination with Dr. Nagel.

This Summer 2011 issue marks the third issue of the third year of IEEE Solid-State Circuits Magazine. In this issue, we are proud to feature articles about the technical innovations and impact of Prof. Kenneth Laker, who is a faculty member at the University of Pennsylvania. We hope that you will enjoy reading them, and we are grateful to our expert authors for contributing to this issue.

In the Summer 2010 and Fall 2010 issues, we are honored to feature the work of Alberto Sangiovanni-Vincentelli, a technical and intellectual pioneer at the University of California at Berkeley.

Welcome to the Spring 2010 issue of IEEE Solid-State Circuits Magazine! This Spring 2010 issue, profiling the career of John Meredith as a life-long member of the IEEE, and featuring a profile of the IEEE by 2008 IEEE President Lew Terman, marks the second issue of the second year of this magazine. As with the previous issues, we remain thankful for the support and initiatives of Executive Director Anne O'Neill, SSCS Technology Editor Dick Jaeger, SSCS Treasurer Rakesh Kumar, and News Editor Katherine Olstein and for the columns of Pengfei Zhang, associate editor of Asia and Africa, Tony Harker, associate editor of Europe, and Tom Lee, contributing editor. The goal of each issue of IEEE Solid-State Circuits Magazine continues to be to create a series of self-contained resources, with original sources and new contributions by experts describing the current state of affairs in technology in view of the influence of original papers and/or patents.

With this Winter 2009 issue, the SSCS Newsletter transforms into IEEE Solid-State Circuits Magazine, thanks to the initiative of Executive Director Anne O'Neill, IEEE Solid-State Circuits Society (SSCS) Past President Dick Jaeger, and SSCS Treasurer Rakesh Kumar. The transition process during the past months involved presentations to the SSCS AdCom and IEEE TAB by Prof. Jaeger and Dr. Kumar and required the approval of both groups. The design of the magazine was executed by the IEEE Magazines Department, whose goal was to bring it into line with other IEEE magazine offerings.

SILICON oxidation is perhaps the most common process in the fabrication of electronic devices. The silicon/silicon dioxide inter-face has excellent electrical properties which are employed in field-effect devices and surface passivation, and are arguably responsible for the dominance of silicon technology in the micro-electronics industry. As device dimensions shrink, the need for high-quality oxides grown at increasingly lower thicknesses and temperatures has demanded ever more perfect, extremely flat Si/SiO2 interfaces. Here we use transmission electron microscopy to image exposed and buried monatomic interfacial steps at the Si/SiO2 interface during oxidation. The results show that extremely flat boundaries can be formed at low temperatures and that atomic steps do not play a dominant role in the oxidation process itself. A simple bulk-terminated Si/amorphous SiO2 inter-face is consistent with our data.

Surface-sensitive bulk-forbidden Bragg reflections have been used to study the oxidation of silicon. Images reveal the appearance of atomic steps on clean silicon surfaces and after oxide growth. Diffraction patterns given quantitative estimates of buried interface roughness from plan-view samples. Diffracted beam intensities allow atomistic analysis of the O 2 / Si surface interaction during the initial stages of oxidation.

We have developed a novel technique for determining interfacial roughness from plan‐view transmission electron diffraction. Certain bulk forbidden Bragg reflections can occur due to crystal termination at surfaces and are very sensitive to steps on crystal boundaries. We demonstrate the technique in the study of Si/SiO2 interfaces and observe that interfaces appear to be significantly flatter than previously found, especially after post‐oxidation annealing. The technique is simply quantified and is more reliable than those which require stripping of the oxide to expose the interface.

Using a UHV transmission electron microscope we have examined the initial stages of Si oxidation. Using the surface-sensitive forbidden 1/3 reflection on Si (111) we have imaged surface steps at various stages of oxidation, including buried Si/SiO 2 interface formation.

We discuss applications of an ultra-high vacuum TEM to the study of clean Si surfaces and in-situ deposited films. For the Nisi2 on Si system, we show the importance of metastable phases during growth. For native oxidation of Si, the behavior of individual atomic steps is viewed. In summary, moderate resolution TEM and diffraction is shown to have a great deal to contribute to semiconductor surface science primarily because of the kinematical diffraction by monolayers and the penetration to view sub-surface phenomena.

Interfacial roughness can be measured at buried interfaces using plan view transmission electron diffraction. The method relies on surface termination Bragg reflections and is applied to the Si/SiO2 system. In contrast to other methods, this does not require stripping of the SiO2 overlayer or projection assumptions. We find that thermal oxide interfaces are significantly flatter than previously supposed.The Si/SiO2 interface has been extensively examined by a wide variety of techniques. A subset of these studies have focussed on the interfacial roughness and it has been shown that increased step density reduces electron mobility.[1, 2 ] Although supporting the correlation of mobility with step density, the data presented here shows thermally oxidized Si/SiO2 interfaces to be significantly flatter than previously assumed.