A novel TEM technique for junction delineation in integrated circuits

1990 ◽  
Vol 48 (4) ◽  
pp. 748-749
Author(s):  
A. Romano ◽  
J. Vanhellemont ◽  
A. De Keersgieter ◽  
W. Vandervorst ◽  
J. R. Morante ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Cross Section ◽  
Chemical Etching ◽  
Etching Rate ◽  
Annealed Sample ◽  
Doping Profile ◽  
Silicon Substrates ◽  
Low Concentrations ◽  
Combined Action ◽  
Established Technique

Ion implantation is a well established technique to dope selectively prespecified regions of silicon substrates. It has the drawback that a thermal treatment is required to activate the dopant and to reconstruct the crystal lattice. This leads to dopant diffusion in depth and also laterally, when the implantation has been preformed through a patterned mask.In this paper two different approaches to determine the doping profile using chemical etching and TEM are presented. Cross-section specimens are prepared using a technique described elsewhere, followed by preferential etching.The first approach is well established and is based on the combined action of HF and HNO3.Low concentrations of HF are used to keep the etching rate low enough. Figure 1 shows a cross-section of a boron implanted and annealed sample which has been etched using the solution HF(40%):HNO3(65%)= 1:300 at 5°C for 80 seconds. The etching rate is proportional to the doping level, as shown in figure 2 and it can be observed that the lowest level which one can delineate with this solution is of the order of 1017cm−3, which is in agreement with the delineated level of figure 1, namely 6·1017 cm−3.

Formation of defects in implanted hipox-structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1406-1407
Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Semiconductor Devices ◽  
Silicon Substrates ◽  
Processing Conditions ◽  
Pressure Oxidation ◽  
Deep Trench ◽  
Local Oxidation ◽  
Trench Isolation ◽  
And Behavior

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.

Root Cause Analysis Techniques Using Picosecond Time Resolved LADA

2014 ◽  
Author(s):  
Dan Bodoh ◽  
Kent Erington ◽  
Kris Dickson ◽  
George Lange ◽  
Carey Wu ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Picosecond Laser ◽  
Root Cause Analysis ◽  
Fault Isolation ◽  
Time Resolved ◽  
Cause Analysis ◽  
Root Cause ◽  
Design And Manufacturing ◽  
Multiple Interactions ◽  
Established Technique

Abstract Laser-assisted device alteration (LADA) is an established technique used to identify critical speed paths in integrated circuits. LADA can reveal the physical location of a speed path, but not the timing of the speed path. This paper describes the root cause analysis benefits of 1064nm time resolved LADA (TR-LADA) with a picosecond laser. It shows several examples of how picosecond TR-LADA has complemented the existing fault isolation toolset and has allowed for quicker resolution of design and manufacturing issues. The paper explains how TR-LADA increases the LADA localization resolution by eliminating the well interaction, provides the timing of the event detected by LADA, indicates the propagation direction of the critical signals detected by LADA, allows the analyst to infer the logic values of the critical signals, and separates multiple interactions occurring at the same site for better understanding of the critical signals.

Microfabricated Fiber Probe by Combination of Electric Arc Discharge and Chemical Etching Techniques

2012 ◽  
Vol 462 ◽  
pp. 38-41 ◽  
Author(s):  
Wan Maisarah Mukhtar ◽  
P. Susthitha Menon ◽  
Sahbudin Shaari
Keyword(s):  
Optical Fibers ◽  
Chemical Etching ◽  
Arc Discharge ◽  
Etching Rate ◽  
Electric Arc ◽  
Buffer Solution ◽  
Fiber Probe ◽  
Optical Fiber Probes ◽  
Electric Arc Discharge ◽  
Fiber Probes

In this study, optical fiber probes were fabricated by combination of electric arc discharge and chemical etching techniques. Size of tips diameters fabricated using different etching solutions were observed. When the optical fibers were pulled and heated by the electric arc discharge using a fusion splicer, fiber tips with few microns in diameter were obtained. To minimize the tips diameter, the pulled fiber probes were etched vertically for 10 minutes using two different etching solutions namely 49% HF and HF buffer solution (49% HF and 40% NH4F) with ratio of 2:1. A thick overlayer was added on top of the HF solution to prevent dangerous vapors escape to the environment. When the tapered part of the pulled fiber (FP1) was dipped into 49% HF solution, the diameter of tip was slightly decreased from 4.41μm to 1.31μm with etching rate of 5.17x10-3 μms-1. When the pulled fiber (FP2) was etched into HF buffer solution, the etching rate was increased up to 52.35% with the etching rate of 10.85x10-3μms-1. The tip diameter was reduced from 7.01μm to 468.9 nm in diameter. Combination of “heat and pull” technique with chemical etching by using HF buffer solution produced fiber probe with small tip diameter.

Diffusion Phenomena of the Oxygen and Nitrogen in Niobium by Mechanical Spectroscopy

2010 ◽  
Vol 297-301 ◽  
pp. 1346-1353
Author(s):  
Odila Florêncio ◽  
Paulo Sergio Silva ◽  
Carlos Roberto Grandini
Keyword(s):  
Diffusion Coefficients ◽  
Short Range ◽  
Annealed Sample ◽  
Relaxation Processes ◽  
Torsion Pendulum ◽  
Mechanical Spectroscopy ◽  
Interstitial Diffusion ◽  
Relaxation Parameters ◽  
Low Concentrations ◽  
Diffusion Phenomena

The short-range diffusion phenomenon (Snoek Effect) was investigated by mechanical spectroscopy measurements between 300 K and 650 K, in a polycrystalline niobium sample, containing oxygen and nitrogen, using a torsion pendulum. Experimental spectra of anelastic relaxation were obtained under three conditions: as-received sample; annealed sample and subsequently annealed in an oxygen atmosphere for three hours at 1170 K in partial pressure of 5x10-5mbar. The experimental spectra obtained were decomposed in elementary Debye peaks and the anelastic relaxation processes were identified. With anelastic relaxation parameters and the lattice parameters, the interstitial diffusion coefficients of the oxygen and nitrogen in niobium were calculated for each kind of preferential occupation (octahedral and tetrahedral). The results were compared with the literature data, and confirmed that the best adjustment is for the preferential occupation octahedral model for low concentrations of interstitial solutes, but at higher concentration of oxygen were observed deviations of experimental data for the interstitial diffusion coefficients of oxygen in niobium when compared with the literature data, this could be related to the possible occurrence of a double occupation of interstitial sites in the niobium lattice by oxygen interstitials.

Laser cross section measurement for the evaluation of single-event effects in integrated circuits

2000 ◽  
Vol 40 (8-10) ◽  
pp. 1371-1375 ◽  
Author(s):  
V. Pouget ◽  
P. Fouillat ◽  
D. Lewis ◽  
H. Lapuyade ◽  
F. Darracq ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Cross Section ◽  
Single Event ◽  
Cross Section Measurement ◽  
Single Event Effects ◽  
Section Measurement

scholarly journals Specific identification of fibrin polymers, fibrinogen degradation products, and crosslinked fibrin degradation products in plasma and serum with a new sensitive technique

Blood ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 589-597
Author(s):  
DG Connaghan ◽  
CW Francis ◽  
DA Lane ◽  
VJ Marder
Keyword(s):  
Degradation Products ◽  
Sodium Dodecyl ◽  
Fibrinolytic Therapy ◽  
Electrophoretic Patterns ◽  
Fibrin Degradation Products ◽  
Low Concentrations ◽  
Combined Action ◽  
Derivatives Of ◽  
Normal Controls ◽  
Immunological Identification

A new method is described for identifying low concentrations of circulating derivatives of fibrinogen and fibrin, even when present in heterogeneous mixtures. This technique is applicable to plasma and serum and uses electrophoresis in 2% agarose in the presence of sodium dodecyl sulfate (SDS) followed by immunological identification of separated derivatives, using radiolabeled antifibrinogen antiserum and autoradiography. Unique electrophoretic patterns distinguish plasmic derivatives of crosslinked fibrin from those of fibrinogen and also identify crosslinked fibrin polymers produced by the combined action of thrombin and factor XIII on fibrinogen. The assay is sensitive to a concentration of 0.1 micrograms/mL of fibrinogen in serum or plasma. Fibrin polymers, plasmic degradation products of fibrinogen, and plasmic degradation products of crosslinked fibrin were detected in the plasma or serum of a patient with disseminated intravascular coagulation. Plasmic derivatives of both fibrinogen and crosslinked fibrin appeared in serum in the course of fibrinolytic therapy for pulmonary embolism, whereas during acute myocardial infarction a marked increase in the proportion of fibrin polymers in plasma was found in comparison with normal controls. Thus, the procedure can distinguish between the simultaneous processes of fibrin polymer formation, fibrinogenolysis, and fibrinolysis, and is sufficiently sensitive to detect relevant quantities of derivatives in pathologic conditions.

scholarly journals Metal-Assisted Chemical Etching for Anisotropic Deep Trenching of GaN Array

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3179
Author(s):  
Qi Wang ◽  
Kehong Zhou ◽  
Shuai Zhao ◽  
Wen Yang ◽  
Hongsheng Zhang ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Low Cost ◽  
Etching Rate ◽  
Surface Damage ◽  
Device Fabrication ◽  
Irreversible Damage ◽  
Catalytic Role ◽  
Metal Assisted Chemical Etching ◽  
Gan Etching

Realizing the anisotropic deep trenching of GaN without surface damage is essential for the fabrication of GaN-based devices. However, traditional dry etching technologies introduce irreversible damage to GaN and degrade the performance of the device. In this paper, we demonstrate a damage-free, rapid metal-assisted chemical etching (MacEtch) method and perform an anisotropic, deep trenching of a GaN array. Regular GaN microarrays are fabricated based on the proposed method, in which CuSO4 and HF are adopted as etchants while ultraviolet light and Ni/Ag mask are applied to catalyze the etching process of GaN, reaching an etching rate of 100 nm/min. We comprehensively explore the etching mechanism by adopting three different patterns, comparing a Ni/Ag mask with a SiN mask, and adjusting the etchant proportion. Under the catalytic role of Ni/Ag, the GaN etching rate nearby the metal mask is much faster than that of other parts, which contributes to the formation of deep trenches. Furthermore, an optimized etchant is studied to restrain the disorder accumulation of excessive Cu particles and guarantee a continuous etching result. Notably, our work presents a novel low-cost MacEtch method to achieve GaN deep etching at room temperature, which may promote the evolution of GaN-based device fabrication.

scholarly journals Focused Ion Beam Etching of GaN

1999 ◽  
Vol 4 (S1) ◽  
pp. 769-774 ◽  
Author(s):  
C. Flierl ◽  
I.H. White ◽  
M. Kuball ◽  
P.J. Heard ◽  
G.C. Allen ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Etching Rate ◽  
Side Wall ◽  
Device Fabrication ◽  
Direct Write ◽  
Ion Beam Etching ◽  
Etched Surface ◽  
A Current ◽  
Established Technique

We have investigated the use of focused ion beam (FIB) etching for the fabrication of GaN-based devices. Although work has shown that conventional reactive ion etching (RIE) is in most cases appropriate for the GaN device fabrication, the direct write facility of FIB etching – a well-established technique for optical mask repair and for IC failure analysis and repair – without the requirement for depositing an etch mask is invaluable. A gallium ion beam of about 20nm diameter was used to sputter GaN material. The etching rate depends linearly on the ion dose per area with a slope of 3.5 × 10−4 μm3/pC. At a current of 3nA, for example, this corresponds to an each rate of 1.05 μm3/s. Good etching qualities have been achieved with a side wall roughness significantly below 0.1 μm. Change in the roughness of the etched surface plane stay below 8nm.

BALLISTIC COLLECTION TRANSISTORS AND THEIR APPLICATIONS

1994 ◽  
Vol 05 (03) ◽  
pp. 349-379 ◽  
Author(s):  
T. ISHIBASHI ◽  
Y. YAMAUCHI ◽  
E. SANO ◽  
H. NAKAJIMA ◽  
Y. MATSUOKA
Keyword(s):  
Integrated Circuits ◽  
High Speed ◽  
Monte Carlo Analysis ◽  
Heterojunction Bipolar Transistor ◽  
Doping Profile ◽  
Electron Velocity ◽  
Collector Current ◽  
Microwave Characterization ◽  
Current Densities ◽  
Dynamic Frequency

We describe the design, fabrication and application of ballistic collection transistors (BCTs) in which electron velocity overshoot is introduced in the collector of a GaAs-based heterojunction bipolar transistor. The guideline for the BCT design is the effective confinement of electrons to the Γ-valley, as simulated by Monte Carlo analysis, and the control of electron energy is accomplished basically with an i-p+-n+ doping profile. Microwave characterization demonstrates the existence of significant overshoot and cutoff frequencies higher than 100 GHz at collector current densities in the mid 104 A/cm 2 range for a typical BCT structure. Some high speed integrated circuits implemented with BCTs include a selector circuit that operates at bit rates up to 40 Gb/s, a dynamic frequency divider with divide-by-four function up to 50 GHz and a broadband preamplifier having an S21 bandwidth as high as 40 GHz.

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