scholarly journals Hybrid CMP Slurry Supply System Using Ionization and Atomization

2021 ◽  
Vol 11 (5) ◽  
pp. 2217
Author(s):  
Hoseong Jo ◽  
Da Sol Lee ◽  
Seon Ho Jeong ◽  
Hyun Seop Lee ◽  
Hae Do Jeong

Chemical mechanical planarization (CMP) is frequently used in semiconductor manufacturing to polish the surfaces of multiple layers in a wafer. The CMP uses a slurry that aids in fabricating a smooth surface by removing the excess materials. However, excessive use of slurry affects the environment and is expensive. Therefore, we propose a hybrid slurry supply system that combines ionization and atomization to reduce slurry consumption and improve the polishing quality. The proposed hybrid system atomizes the ionized slurry using electrolysis and a spray slurry nozzle. We compared the material removal rate (MRR) and polishing uniformity based on the slurry supply systems used in Cu and SiO2 non-patterned wafers. Additionally, the step height reduction and dishing were compared in the Cu-patterned wafers. The experimental analysis using the hybrid system confirmed a 23% and 25% improvement in the MRR and uniformity, respectively, in comparison with the conventional slurry supply system. This improvement can be attributed to the chemical activation and uniform supply of the ionized and atomized slurries, respectively. Moreover, a significant reduction was observed in dishing and pitch-size dependence. Furthermore, the proposed system prevents heat accumulation between the CMP processes, serving as a cooling system.

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7825
Author(s):  
Pradeep Shakya ◽  
Gimson Ng ◽  
Xiaoli Zhou ◽  
Yew Wah Wong ◽  
Swapnil Dubey ◽  
...  

A hybrid cooling system which combines natural ventilation with a radiant cooling system for a hot and humid climate was studied. Indirect evaporative cooling was used to produce chilled water at temperatures slightly higher than the dew point. With this hybrid system, the condensation issue on the panel surface of a chilled ceiling was overcome. A computational fluid dynamics (CFD) model was employed to determine the cooling load and the parameters required for thermal comfort analysis for this hybrid system in an office-sized, well-insulated test room. Upon closer investigation, it was found that the thermal comfort by the hybrid system was acceptable only in limited outdoor conditions. Therefore, the hybrid system with a secondary fresh air supply system was suggested. Furthermore, the energy consumptions of conventional all-air, radiant cooling, and hybrid systems including the secondary air supply system were compared under similar thermal comfort conditions. The predicted results indicated that the hybrid system saves up to 77% and 61% of primary energy when compared with all-air and radiant cooling systems, respectively, while maintaining similar thermal comfort.


2007 ◽  
Vol 22 (3) ◽  
pp. 777-787 ◽  
Author(s):  
Hyun-Goo Kang ◽  
Hyung-Soon Park ◽  
Ungyu Paik ◽  
Jea-Gun Park

The effects of the molecular weight and concentration of poly(acrylic acid) (PAA) with different primary abrasive sizes in ceria slurry on the nitride film loss, removal rate, film surface roughness, and removal selectivity of SiO2-to-Si3N4 films were investigated by performing chemical mechanical polishing (CMP) experiments using blanket and patterned wafers. In the case of the blanket wafers, we found that for a lower PAA molecular weight, the removal selectivity of SiO2-to-Si3N4 films increased more significantly with increasing PAA concentration in slurry containing a larger primary abrasive size. For the patterned wafers, with a higher PAA molecular weight in the ceria slurry suspension, the erosion of the Si3N4 film was less, but the removed amount was also smaller, and the surface roughness became worse after CMP. These results can be qualitatively explained by the layer of PAA adsorbed on the film surface, in terms of electrostatic interaction and rheological behavior.


2021 ◽  
Vol 11 (4) ◽  
pp. 1783
Author(s):  
Ming-Yi Tsai ◽  
Kun-Ying Li ◽  
Sun-Yu Ji

In this study, special ceramic grinding plates impregnated with diamond grit and other abrasives, as well as self-made lapping plates, were used to prepare the surface of single-crystal silicon carbide (SiC) wafers. This novel approach enhanced the process and reduced the final chemical mechanical planarization (CMP) polishing time. Two different grinding plates with pads impregnated with mixed abrasives were prepared: one with self-modified diamond + SiC and a ceramic binder and one with self-modified diamond + SiO2 + Al2O3 + SiC and a ceramic binder. The surface properties and removal rate of the SiC substrate were investigated and a comparison with the traditional method was conducted. The experimental results showed that the material removal rate (MRR) was higher for the SiC substrate with the mixed abrasive lapping plate than for the traditional method. The grinding wear rate could be reduced by 31.6%. The surface roughness of the samples polished using the diamond-impregnated lapping plate was markedly better than that of the samples polished using the copper plate. However, while the surface finish was better and the grinding efficiency was high, the wear rate of the mixed abrasive-impregnated polishing plates was high. This was a clear indication that this novel method was effective and could be used for SiC grinding and lapping.


Author(s):  
Kara G. Cafferty ◽  
David J. Muth ◽  
Jacob J. Jacobson ◽  
Kenneth M. Bryden

Engineering feedstock supply systems that deliver affordable, high-quality biomass remains a challenge for the emerging bioenergy industry. Cellulosic biomass is geographically distributed and has diverse physical and chemical properties. Because of this feedstock supply systems that deliver cellulosic biomass resources to biorefineries require integration of a broad set of engineered unit operations. These unit operations include harvest and collection, storage, preprocessing, and transportation processes. Design decisions for each feedstock supply system unit operation impact the engineering design and performance of the other system elements. These interdependencies are further complicated by spatial and temporal variances such as climate conditions and biomass characteristics. This paper develops an integrated model that couples a SQL-based data management engine and systems dynamics models to design and evaluate biomass feedstock supply systems. The integrated model, called the Biomass Logistics Model (BLM), includes a suite of databases that provide 1) engineering performance data for hundreds of equipment systems, 2) spatially explicit labor cost datasets, and 3) local tax and regulation data. The BLM analytic engine is built in the systems dynamics software package Powersim™. The BLM is designed to work with thermochemical and biochemical based biofuel conversion platforms and accommodates a range of cellulosic biomass types (i.e., herbaceous residues, short-rotation woody and herbaceous energy crops, woody residues, algae, etc.). The BLM simulates the flow of biomass through the entire supply chain, tracking changes in feedstock characteristics (i.e., moisture content, dry matter, ash content, and dry bulk density) as influenced by the various operations in the supply chain. By accounting for all of the equipment that comes into contact with biomass from the point of harvest to the throat of the conversion facility and the change in characteristics, the BLM evaluates economic performance of the engineered system, as well as determining energy consumption and green house gas performance of the design. This paper presents a BLM case study delivering corn stover to produce cellulosic ethanol. The case study utilizes the BLM to model the performance of several feedstock supply system designs. The case study also explores the impact of temporal variations in climate conditions to test the sensitivity of the engineering designs. Results from the case study show that under certain conditions corn stover can be delivered to the cellulosic ethanol biorefinery for $35/dry ton.


2013 ◽  
Vol 634-638 ◽  
pp. 2949-2954
Author(s):  
Xin Liang Tang ◽  
Yu Ling Liu ◽  
Hong Yuan Zhang ◽  
Jie Bao

Silica abrasive plays an important role in chemical mechanical planarization (CMP) of copper. In this paper, effect of different silica abrasive concentrations on copper removal rate and planarization performance of copper was investigated. The results show that the copper removal rate was increased as the concentration of silica abrasive increase. However, excessive abrasive will lead to a decreased copper removal rate. The initial step height values of the multilayer copper wafers were all about 2500Å, and after being polished for 30s, the remaining values of step height of slurry A, B, C and D were 717 Å, 906 Å, 1222 Å and 1493 Å. It indicates that alkaline copper slurries with different abrasive concentrations all had a good planarization performance on copper patterned wafer CMP. As the abrasive concentration increased, the planarization capability was enhanced.


2007 ◽  
Vol 991 ◽  
Author(s):  
Tae-Young Kwon ◽  
In-Kwon Kim ◽  
Jin-Goo Park

ABSTRACTThe purpose of this study was to characterize KOH based electrolytes and effects of additives on electro-chemical mechanical planarization. The electrochemical mechanical polisher was made to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat. Cu disk of 2 inch was used as a working electrode and Pt electroplated platen was used as a counter electrode. KOH was used as the electrolyte. H2O2 and citric acid were used as additives for the ECMP of Cu. In static and dynamic potentiodynamic measurements, the corrosion potential decreased and corrosion current increased as a function of KOH concentration. In dynamic state, different potentiodynamic curve was obtained when compared to the static state. The current density did not decrease in passivation region by mechanical polishing effect. The static etch and removal rate were measured as function of KOH concentration and applied voltage. In ECMP system, polishing was performed at 30 rpm and 1 psi. The removal rate was about 60 nm/min at 0.3 V when 5 wt% KOH was used. Also, the effect of additive was investigated in KOH based electrolyte on removal rates. As a result, The removal rate was increased to 350 nm/min when 5wt% KOH, 5vol% H2O2, 0.3 M citric acid were used.


2000 ◽  
Vol 612 ◽  
Author(s):  
Shyama P. Mukherjee ◽  
Joseph A. Levert ◽  
Donald S. Debear

ABSTRACTThe present work describes the process principles of “Spin-Etch Planarization” (SEP), an emerging method of planarization of dual damascene copper interconnects. The process involves a uniform removal of copper and the planarization of surface topography of copper interconnects by dispensing abrasive free etchants to a rotating wafer. The primary process parameters comprise of (a) Physics and chemistry of etchants, and (b) Nature of fluid flow on a spinning wafer. It is evident, that unlike conventional chemical-mechanical planarization, which has a large number of variables due to the presence of pads, normal load, and abrasives, SEP has a smaller number of process parameters and most of them are primary in nature. Based on our preliminary works, we have presented the basic technical parameters that contribute to the process and satisfy the basic requirements of planarization such as (a) Uniformity of removal (b) Removal rate (c) Degree of Planarization (d) Selectivity. The anticipated advantages and some inherent limitations are discussed in the context of process principles. We believe that when fully developed, SEP will be a simple, predictable and controllable process.


Author(s):  
A. Yu. Efimov ◽  
M. N. Saraikin ◽  
V. A. Efimov ◽  
E. V. Troshkin

Цель. Большинство известных компрессоров используют механический привод от электродвигателя для достижения своей цели – перекачки необходимого потребителю количества сжатого воздуха. Во время работы любого компрессора прямого вытеснения выделяется большое количество тепла, которое вырабатывается как за счет трения движущихся частей блока, так и при сжатии воздуха.Метод. Предложена система охлаждения поршневого компрессора с импульсным потоком теплоносителя с последующим использованием тепла в системе ГВС при помощи пластинчатого теплообменника, зарекомендовавшего себя своей компактностью и эффективностью.Результат. С целью более глубокого отбора тепла в качестве типа движения нагреваемой линии был предложен импульсный поток, организованный при помощи ударного узла.Вывод. В качестве оценки системы было проведено сравнение с аналогичной системой со стационарным потоком, как по техническим параметрам (температура рубашки компрессора t руб. ; температура воздуха в ресивере tвозд. ; средняя тепловая мощность N ср. ; коэффициент теплопередачи K ; объём воздуха, перекачиваемый за 1 цикл Vвозд. ) так и по экономическим параметрам (время окупаемости установки по сравнению с аналогичной установкой со стационарным потоком Tок ).


2020 ◽  
Vol 219 ◽  
pp. 02001
Author(s):  
Nikolay Ilkevich ◽  
Tatyana Dzyubina ◽  
Zhanna Kalinina

This paper proposes taking into account new properties of gas supply systems in a mathematical model of flow distribution in comparison with the traditional formulation. The approach suggests introducing an arc coefficient, which allows for changes in the magnitude of gas flow passing along the arc, a vector of an increase in the arc throughput, and lower constraints on the gas flow along the arc. We also propose considering a new economic environment, namely, new criteria for optimizing the flow distribution and setting fictitious gas prices for consumers. These criteria enable us to take account of the priority gas supply to a definite group of consumers. As an example, the calculation of gas flows for the aggregated Unified Gas Supply System (UGSS) for 2030 is considered. This calculation takes into account the arc coefficients and the increase in the throughput of arcs.


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