Slight Radiation Damage in Silicon for Si-Based Device Processing

1993 ◽  
Vol 316 ◽  
Author(s):  
A. Harnau ◽  
H.-U. Schreiber

ABSTRACTUtilization of radiation damage by means of ion implantation to reduce parasitic capacitances in GaAs integrated circuits has become a well-established technique in the last years. Similar to GaAs, novel high-speed silicon-based devices, e.g. the Si/SiGe heterojunction bipolar transistor, are generally marked by additional short time annealing related to doping activation and a metallization annealing step in the range of 400 °C .For reproducing the external base region of such devices, Si-p+nn+ diodes were realized and investigated using I-V and C-V measurements. Slight radiation damage was achieved by Ne-implantation. Apart from enhanced leakage currents due to space charge recombination, capacitance reduction for frequencies above 50 kHz was observed even for a n-layer doping concentration as high as 1 to 2x1017 cm-3 including a 12 min 400 °C annealing step. Preliminary tests with 250 keV-Ne-ions within a dose range between 1013 and 1014 cm-2 were carried out with Schottky diodes on moderately doped n-type Si-substrate (0.3 Ωcm). For a high temperature furnace anneal at 900 °C (2 min), no capacitance reduction could be observed.Compared to previous results with Ar-implantation to obtain amorphized silicon layers, this technique allows a more easy technological handling concerning the metallization and the use of a simple photoresist pattern.

Author(s):  
E.D. Wolf

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.


Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.


Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.


Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.


Author(s):  
Mark Kimball

Abstract This article presents a novel tool designed to allow circuit node measurements in a radio frequency (RF) integrated circuit. The discussion covers RF circuit problems; provides details on the Radio Probe design, which achieves an input impedance of 50Kohms and an overall attenuation factor of 0 dB; and describes signal to noise issues in the output signal, along with their improvement techniques. This cost-effective solution incorporates features that make it well suited to the task of differential measurement of circuit nodes within an RF IC. The Radio Probe concept offers a number of advantages compared to active probes. It is a single frequency measurement tool, so it complements, rather than replaces, active probes.


Author(s):  
Kenneth Krieg ◽  
Richard Qi ◽  
Douglas Thomson ◽  
Greg Bridges

Abstract A contact probing system for surface imaging and real-time signal measurement of deep sub-micron integrated circuits is discussed. The probe fits on a standard probe-station and utilizes a conductive atomic force microscope tip to rapidly measure the surface topography and acquire real-time highfrequency signals from features as small as 0.18 micron. The micromachined probe structure minimizes parasitic coupling and the probe achieves a bandwidth greater than 3 GHz, with a capacitive loading of less than 120 fF. High-resolution images of submicron structures and waveforms acquired from high-speed devices are presented.


2021 ◽  
Vol 11 (3) ◽  
pp. 933
Author(s):  
Mario Lucido

The method of analytical preconditioning combines the discretization and the analytical regularization of a singular integral equation in a single step. In a recent paper by the author, such a method has been applied to a spectral domain integral equation formulation devised to analyze the propagation in polygonal cross-section microstrip lines, which are widely used as high-speed interconnects in monolithic microwave and millimeter waves integrated circuits. By choosing analytically Fourier transformable expansion functions reconstructing the behavior of the fields on the wedges, fast convergence is achieved, and the convolution integrals are expressed in closed form. However, the coefficient matrix elements are one-dimensional improper integrals of oscillating and, in the worst cases, slowly decaying functions. In this paper, a novel technique for the efficient evaluation of such kind of integrals is proposed. By means of a procedure based on Cauchy integral theorem, the general coefficient matrix element is written as a linear combination of fast converging integrals. As shown in the numerical results section, the proposed technique always outperforms the analytical asymptotic acceleration technique, especially when highly accurate solutions are required.


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