Track etch formation in thin SSNTD in case of variable etch rate ratio

1984 ◽  
Vol 8 (1-4) ◽  
pp. 13-16 ◽  
Author(s):  
Almasi G. ◽  
B. Kunsch
Keyword(s):  
Rate Ratio ◽  
Etch Rate ◽  
Track Etch

scholarly journals Gamma Irradiation Effects on Track Properties of PADC-American Acrylics Track Detector

2012 ◽  
Vol 9 (4) ◽  
pp. 2226-2231
Author(s):  
Dipak Sinha
Keyword(s):  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Rate Ratio ◽  
Etch Rate ◽  
Dose Range ◽  
Track Detector ◽  
Irradiation Effects ◽  
Etch Rates ◽  
Track Etch

Gamma irradiation effects on track properties of Polyallyl Diglycol Carbonate (PADC) track detector (PADC-American Acrylics) are studied in the dose range of 101-106Gy. It is observed that due to gamma exposure the bulk and track-etch rates of the detector increases. This increase in both etch-rates is more pronounced in post gamma exposed PADC detectors. The etch-rate ratio (S) for both pre and post-gamma exposed detectors decreases with increasing etching temperature at the dose of 106Gy. At a higher etching temperature of 70ºC, the etch rates ratio becomes almost equal for post gamma exposed detector. Etching efficiency of the detector is found to be much higher when exposed to gamma radiation. However it is observed that at the etching temperature of 70ºC, etching efficiency for both pre and post-gamma exposed samples tends to become almost equal to the pristine one.

An Etch-Back Planarization Process Using A Sacrificial Polymide Layer

1991 ◽  
Vol 240 ◽  
Author(s):  
J. R. Lothian ◽  
T. R. Fullowan
Keyword(s):  
Surface Topography ◽  
Dielectric Layer ◽  
Rate Ratio ◽  
Parallel Plate ◽  
Etch Rate ◽  
Dielectric Film ◽  
Sacrificial Layer ◽  
Loading Effect ◽  
Planarization Process ◽  
Etching System

ABSTRACTAn etch-back polymide planarization process for the emitter contact of AlGaAs/GaAs HBTs using PC-1500 is presented. The degree of surface topography has a major impact on the yield in HBT fabrication. A planarization process using a spin-on sacrificial layer to produce a planar interlevel dielectric layer would be very beneficial in allowing thicker and more uniform emitter contacts therefore enhancing the yield and current handling capability. The PC-1500 polymer flows at 200°C and provides a much better planarity than regular photoresist. For patterns from -3 μm to 250 this polymer can achieve 80% to 92% planarity. The wafers were etched in a parallel plate, single wafer reactive ion-etching system with a mixture of oxygen and Freon-14. The etch rate of this polymer increased with the oxygen content of the discharge then became fairly constant at high O2 concentrations while the etch rate of the underlying dielectric film (SiN) was proportional to the Freon 14 content. This new polymer shows little loading effect. A 1:1 etch rate ratio of SiN to PC-1500 was established for good planarity.

A method for increasing the etch‐rate ratio of oxides to nonoxides in inert‐gas ion milling processes

1980 ◽  
Vol 51 (6) ◽  
pp. 3362-3364 ◽  
Author(s):  
U. Gerlach‐Meyer ◽  
J. W. Coburn ◽  
E. Kay
Keyword(s):  
Rate Ratio ◽  
Etch Rate ◽  
Inert Gas ◽  
Ion Milling

Alpha track registration and revelation in CR-39 using new etching method for ultratrace alpha radioactivity quantification in solution media

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sushma S. Chavan ◽  
Amol M. Mhatre ◽  
Ashok K. Pandey ◽  
Hemlata K. Bagla
Keyword(s):  
Induction Time ◽  
Chemical Etching ◽  
Etch Rate ◽  
Phase Transfer ◽  
Alpha Activity ◽  
Phase Transfer Catalyst ◽  
Tetraethylammonium Bromide ◽  
Etching Method ◽  
Track Etch ◽  
Registration Efficiency

Abstract A CR-39 based method was developed for measuring the ultra-trace alpha radio activities in aqueous samples having curie levels of γ/β-radio activities. The chemical etching method was optimized to reveal the alpha tracks in CR-39. This new chemical etching method involved the use of a phase transfer catalyst tetraethylammonium bromide which reduced the track revelation induction time without deteriorating the track-etch parameters. The alpha track-etch parameters such as bulk-etch rate, track-etch rate, induction time, and the critical angle of alpha track registration were measured at 60 and 70 °C, with and without using a phase transfer catalyst in the chemical etching for the comparison and optimization. The track registration efficiency of CR-39 in the solution medium was measured using the samples having known alpha activity of mixPu, and value obtained was found to be (4.42 ± 0.12) × 10−4 cm. The registration efficiency value thus obtained was corroborated with the expected efficiency expected from the calculated range of alpha particles in the solution. This CR-39 based method was employed to quantify the alpha activity, as low as 0.2 Bq mL−1, in the aqueous radiopharmaceutical samples having the curie levels of γ/β radio activities.

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