Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers.

ABSTRACT: A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm(2), using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements.

SUBMITTER: Zhang Z

PROVIDER: S-EPMC4880934 | biostudies-other | 2016

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

A novel approach of chemical mechanical polishing using environment-friendly slurry for mercury cadmium telluride semiconductors.

Project description:A novel approach of chemical mechanical polishing (CMP) is developed for mercury cadmium telluride (HgCdTe or MCT) semiconductors. Firstly, fixed-abrasive lapping is used to machine the MCT wafers, and the lapping solution is deionized water. Secondly, the MCT wafers are polished using the developed CMP slurry. The CMP slurry consists of mainly SiO2 nanospheres, H2O2, and malic and citric acids, which are different from previous CMP slurries, in which corrosive and toxic chemical reagents are usually employed. Finally, the polished MCT wafers are cleaned and dried by deionized water and compressed air, respectively. The novel approach of CMP is environment-friendly. Surface roughness Ra, and peak-to-valley (PV) values of 0.45, and 4.74 nm are achieved, respectively on MCT wafers after CMP. The first and second passivating processes are observed in electrochemical measurements on MCT wafers. The fundamental mechanisms of CMP are proposed according to the X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Malic and citric acids dominate the first passivating process, and the CMP slurry governs the second process. Te(4+)3d peaks are absent after CMP induced by the developed CMP slurry, indicating the removing of oxidized films on MCT wafers, which is difficult to achieve using single H2O2 and malic and citric acids solutions.

| S-EPMC4772544 | biostudies-other

Effect of chemical mechanical polishing on surface nature of titanium implants FT-IR and wettability data of titanium implants surface after chemical mechanical polishing implementation.

Project description:Bioactivity of titanium depends on the quality and characteristics of its surface oxide film. Through implementation of chemical mechanical polishing (CMP) process on titanium plates, a protective oxide (titania) film grows on the titanium based implant surface. In this article, surface properties of the titanium oxide are investigated as a function of the CMP process conditions. Surface responses were evaluated in terms of wettability, nano-scale surface roughness and material removal rates (MRR). Surface chemical compositions were also evaluated through Fourier transform infrared spectroscopy (FT-IR).

| S-EPMC5137329 | biostudies-literature

Photo-oxidative degradation of polyacids derived ceria nanoparticle modulation for chemical mechanical polishing.

Project description:The effects of photo-oxidative degradation of polyacids at various concentrations and with different durations of ultraviolet (UV) irradiation on the photo-reduction of ceria nanoparticles were investigated. The effect of UV-treated ceria on the performance of chemical mechanical polishing (CMP) for the dielectric layer was also evaluated. When the polyacids were exposed to UV light, they underwent photo-oxidation with consumption of the dissolved oxygen in slurry. UV-treated ceria particles formed oxygen vacancies by absorbing photon energy, resulting in increased Ce3+ ions concentration on the surface, and when the oxygen level of the solution was lowered by the photo-oxidation of polymers, the formation of Ce3+ ions was promoted from 14.2 to 36.5%. Furthermore, chain scissions of polymers occurred during the oxidation process, and polyacids with lower molecular weights were found to be effective in ceria particle dispersion in terms of the decrease in the mean diameter and size distribution maintaining under 0.1 of polydispersity index. With increasing polyacid concentration and UV irradiation time, the Ce3+ concentration and the dispersity of ceria both increased due to the photo-oxidative degradation of the polymer; this enhanced the CMP performance in terms of 87% improved material removal rate and 48% lowered wafer surface roughness.

| S-EPMC8803865 | biostudies-literature

Breast composition measurement with a cadmium-zinc-telluride based spectral computed tomography system.

Project description:To investigate the feasibility of breast tissue composition in terms of water, lipid, and protein with a cadmium-zinc-telluride (CZT) based computed tomography (CT) system to help better characterize suspicious lesions.Simulations and experimental studies were performed using a spectral CT system equipped with a CZT-based photon-counting detector with energy resolution. Simulations of the figure-of-merit (FOM), the signal-to-noise ratio (SNR) of the dual energy image with respect to the square root of mean glandular dose (MGD), were performed to find the optimal configuration of the experimental acquisition parameters. A calibration phantom 3.175 cm in diameter was constructed from polyoxymethylene plastic with cylindrical holes that were filled with water and oil. Similarly, sized samples of pure adipose and pure lean bovine tissues were used for the three-material decomposition. Tissue composition results computed from the images were compared to the chemical analysis data of the tissue samples.The beam energy was selected to be 100 kVp with a splitting energy of 40 keV. The tissue samples were successfully decomposed into water, lipid, and protein contents. The RMS error of the volumetric percentage for the three-material decomposition, as compared to data from the chemical analysis, was estimated to be approximately 5.7%.The results of this study suggest that the CZT-based photon-counting detector may be employed in the CT system to quantify the water, lipid, and protein mass densities in tissue with a relatively good agreement.

| S-EPMC3292597 | biostudies-other

KDP Aqueous Solution-in-Oil Microemulsion for Ultra-Precision Chemical-Mechanical Polishing of KDP Crystal.

Project description:A novel functional KH₂PO₄ (KDP) aqueous solution-in-oil (KDP aq/O) microemulsion system for KDP crystal ultra-precision chemical-mechanical polishing (CMP) was prepared. The system, which consisted of decanol, Triton X-100, and KH₂PO₄ aqueous solution, was available at room temperature. The functional KDP aq/O microemulsion system was systematically studied and applied as polishing solution to KDP CMP technology. In this study, a controlled deliquescent mechanism was proposed for KDP polishing with the KDP aq/O microemulsion. KDP aqueous solution, the chemical etchant in the polishing process, was caged into the micelles in the microemulsion, leading to a limitation of the reaction between the KDP crystal and KDP aqueous solution only if the microemulsion was deformed under the effect of the external force. Based on the interface reaction dynamics, KDP aqueous solutions with different concentrations (cKDP) were applied to replace water in the traditional water-in-oil (W/O) microemulsion. The practicability of the controlled deliquescent mechanism was proved by the decreasing material removal rate (MRR) with the increasing of the cKDP. As a result, the corrosion pits on the KDP surface were avoided to some degree. Moreover, the roughnesses of KDP with KDP aq/O microemulsion (cKDP was changed from 10 mM to 100 mM) as polishing solutions were smaller than that with the W/O microemulsion. The smallest surface root-mean-square roughness of 1.5 nm was obtained at a 30 mmol/L KDP aq solution, because of the most appropriate deliquescent rate and MRR.

| S-EPMC5503384 | biostudies-literature

Comparative Performances of Dipyridamole and Regadenoson to Detect Myocardial Ischemia using Cardiac Cadmium-Zinc-Telluride Single-Photon Emission Computerized Tomography.

Project description:Objective:We evaluated the relative performances of dipyridamole (Dip) and regadenoson (Reg) in a cohort of patients referred for coronary artery disease diagnosis or follow-up using myocardial perfusion imaging. Materials and Methods:We retrospectively included 515 consecutive patients referred for 99mTc-sestamibi myocardial perfusion single-photon emission computerized tomography (SPECT) on a cadmium-zinc-telluride (CZT) camera after pharmacologic stress. About three quarters (n = 391, 76%) received Dip. Reg was administrated to patients with chronical respiratory disease or with body mass index (BMI) over 38 kg/m2 (n = 124, 24%). Patients with an abnormal stress scan (92%) underwent a rest imaging on the same day. Qualitative interpretation of perfusion images was achieved using QPS software, and the ischemic area was assessed using the 17-segment model. In patients undergoing a stress-rest protocol, perfusion polar plots were postprocessed using automated in-house software to quantify the extension, intensity, and location of the reversible perfusion defect. Statistical comparison between groups was performed using univariate and multivariate analysis. Results:Qualitative analysis concluded to myocardial ischemia in 70% of the patients (69% in the Dip group, 76% in the Reg group, P = ns). In those patients, the number of involved segments (Dip 2.5 ± 1.6, Reg 2.7 ± 1.6, P = ns) and the proportion of patients with an ischemic area larger than two segments (Dip 30%, Reg 37%, P = ns) were comparable. Automated quantification of the reversible perfusion defect demonstrated similar defect extension, intensity, and severity in the two groups. Defect location was identical at the myocardial segment and vascular territory scales. Conclusions:Reg and Dip showed equal performances for ischemic burden characterization using myocardial CZT SPECT.

| S-EPMC6251245 | biostudies-literature

Impact of selenium addition to the cadmium-zinc-telluride matrix for producing high energy resolution X-and gamma-ray detectors.

Project description:Both material quality and detector performance have been steadily improving over the past few years for the leading room temperature radiation detector material cadmium-zinc-telluride (CdZnTe). However, although tremendous progress being made, CdZnTe still suffers from high concentrations of performance-limiting defects, such as Te inclusions, networks of sub-grain boundaries and compositional inhomogeneity due to the higher segregation coefficient of Zn. Adding as low as 2% (atomic) Se into CdZnTe matrix was found to successfully mitigate many performance-limiting defects and provide improved compositional homogeneity. Here we report record-high performance of Virtual Frisch Grid (VFG) detector fabricated from as-grown Cd0.9Zn0.1Te0.98Se0.02 ingot grown by the Traveling Heater Method (THM). Benefiting from superior material quality, we achieved superb energy resolution of 0.77% at 662 keV (as-measured without charge-loss correction algorithms) registered at room temperature. The absence of residual thermal stress in the detector was revealed from white beam X-ray topographic images, which was also confirmed by Infra-Red (IR) transmission imaging under cross polarizers. Furthermore, neither sub-grain boundaries nor their networks were observed from the X-ray topographic image. However, large concentrations of extrinsic impurities were revealed in as-grown materials, suggesting a high likelihood for further reduction in the energy resolution after improved purification of the starting material.

| S-EPMC8121847 | biostudies-literature

Numerical Analysis of the Effect of Retaining Ring Structure on the Chemical Mechanical Polishing Abrasive Motion State.

Project description:Optimizing the retaining ring structure can improve the quality of Chemical Mechanical Polishing (CMP). This study establishes a two-dimensional Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) model, while the model is validated by experiments. The results graphically demonstrate the influence of the retaining ring groove design on the motion of the slurry abrasive particles. The size of the retaining ring groove appears to have a threshold value, above which the abrasives start to have significant distribution in the wafer region. As the groove size continues to increase, the number of abrasives entering the ring increases abruptly and oscillates at specific nodes. The abrasive transfer rate increases with the number of grooves in the early stage but reaches a limit at a certain number of grooves. Meanwhile, the retaining ring position affects the transfer of the abrasives. This study provides a base for optimizing the design of retaining rings.

| S-EPMC9821106 | biostudies-literature

Evaluation data about accuracy of cadmium-zinc-telluride imaging in detecting single and multivessel coronary artery disease: Focus on gender differences.

Project description:The data presented in this article are related to the research article entitled: "Accuracy of cadmium-zinc-telluride imaging in detecting single and multivessel coronary artery disease: is there any gender difference?" (Gimelli et al., 2018). We evaluated gender-related differences in diagnostic accuracy of cadmium-zinc-telluride (CZT) myocardial perfusion imaging (MPI) in detecting single- and multi-vessel coronary artery disease (CAD). We included 1161 consecutive patients with known or suspected coronary artery disease (228, 25% women and 873, 75% men) who had been referred to our laboratory for stress-rest myocardial perfusion imaging (single-day stress-rest low-dose ultrafast protocol). All patients underwent coronary angiography within 30 days; CAD was defined in the presence of a coronary stenosis >70%. Summed stress scores (SSS), summed rest scores (SRS) and summed difference scores (SDS) were obtained. Image quality was graded "good" or better in more than 90% of patients.

| S-EPMC6247448 | biostudies-literature

Polymer link breakage of polyimide-film-surface using hydrolysis reaction accelerator for enhancing chemical-mechanical-planarization polishing-rate.

Project description:In this study, the chemical decomposition of a polyimide-film (i.e., a PI-film)-surface into a soft-film-surface containing negatively charged pyromellitic dianhydride (PMDA) and neutral 4,4'-oxydianiline (ODA) was successfully performed. The chemical decomposition was conducted by designing the slurry containing 350 nm colloidal silica abrasive and small molecules with amine functional groups (i.e., ethylenediamine: EDA) for chemical-mechanical planarization (CMP). This chemical decomposition was performed through two types of hydrolysis reactions, that is, a hydrolysis reaction between OH- ions or R-NH3+ (i.e., EDA with a positively charged amine groups) and oxygen atoms covalently bonded with pyromellitimide on the PI-film-surface. In particular, the degree of slurry adsorption of the PI-film-surface was determined by the EDA concentration in the slurry because of the presence of R-NH3+, that is, a higher EDA concentration resulted in a higher degree of slurry adsorption. In addition, during CMP, the chemical decomposition degree of the PI-film-surface was principally determined by the EDA concentration; that is, the degree of chemical composition was increased noticeably and linearly with the EDA concentration. Thus, the polishing-rate of the PI-film-surface increased notably with the EDA concentration in the CMP slurry.

| S-EPMC8888717 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data