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1.
CsLiB6O10(CLBO) is a new-type nonlinear optical crystal material. CLBO has many good performances, especially the frequency multiplication performance in deep ultraviolet band. CLBO has important application prospect on solid-state UV laser, broad band tunable laser and laser nucleus flame igniter. Though, CLBO will be air slaking and cracking when the ambient humidity is more than 40%, which brings more difficult on CLBO surface finishing. According to the performance and structure characteristic of CLBO crystal, a new water-free slurry applying for CLBO crystal chemical mechanical polishing(CMP) was investigated. The abrasive is SiO2. The influence of polishing processing parameter on polishing process for CLBO crystal was discussed, and the parameter optimal value of polishing plate speed, pressure, pH value and abrasive concentration were determined. Through such parameters, high efficiency and precision plane polishing was gotten. The CLBO CMP process was studied, the results show that low pressure and high speed can improve the CLBO crystal surface removal rate and flatness.  相似文献   

2.
An isotropic etching technique of texturing silicon solar cells has been applied to polycrystalline silicon wafers with different acid concentrations. Optimal etching conditions have been determined by etching rate calculation, scanning electron microscope (SEM) image and reflectance measurement. The surface morphology of the textured wafers varies in accordance with the different etchant concentration which in turn leads to the dissimilarity of etching speed. Textured polycrystalline silicon wafer surfaces display randomly located etched pits which can reduce the surface reflection and enhance the light absorption. The special relationship between reflectivity and etching rate was studied. Reflectance measurements show that isotropic texturing is one of the suitable techniques for texturing polycrys talline silicon wafers and benefits solar cells performances.  相似文献   

3.
The effects of trace element Fe on the corrosion behavior of AZ80 magnesium alloy were investigated by salt spray test and electrochemical measurements.The results show that the corrosion rate decreases with decreasing the trace element Fe content in an approximately linear relation even though the amount of trace element Fe reduces to 0.000 2%(mass fraction).The electrochemical measurements show that the corrosion potential(φcorr)of the alloy with lower trace element Fe content shifts to less negative value.It is suggested that the control trace element by purification is an effective way to enhance the corrosion resistance of AZ80 magnesium alloy.  相似文献   

4.
Electrochemical impedance spectroscopy(EIS) and film thickness measurement have been employed to study the atmospheric corrosion of a weathering steel covered with a thin electrolyte layer in a simulated coastal–industrial atmosphere. The results indicate that the corrosion rate is a function of the covered electrolyte thickness and the wet/dry cycle. Within each wet/dry cycle, the increased corrosion rate is related to the increased Cl-and SO2-4concentration and an enhancement of oxygen diffusion rate with the evaporation of the electrolyte. In addition, the corrosion rate increases during the initial corrosion stage and then decreases as the wet/dry cycle proceeds. Moreover, one mathematical approach based on the numerical integration method to obtain corrosion mass loss of steel from the measurements of EIS has been developed, and this would be useful for the development of indoor simulated atmospheric corrosion tests.  相似文献   

5.
The corrosion behaviors of low-pressure sand cast Mg-10Gd-3Y-0.5Zr(wt.%) alloys in as-cast, solution treated(T4) and aged(T6) conditions were studied by means of immersion test and electrochemical measurements in 5wt.% NaCl solution saturated with Mg(OH)_2. It was observed that the corrosion rate in the T4 condition was lower than that of the as-cast and T6 conditions by both sand casting and permanent mold casting with the same order of as-castT6T4; while the corrosion resistance of the permanent mold casting is superior to the sand casting. The morphologies of the corrosion products are similar porous structures consisting of tiny erect flakes perpendicular to the corroded surface of the alloy, irrespective of the heat treatment conditions. Especially, the corrosion film in T4 condition is more compact than that in the other two conditions. In addition, the severer corrosion happening to the as-cast condition is correlated with the galvanic corrosion between the matrix and the eutectic compounds; while improved corrosion resistance for the T4 and T6 conditions is ascribed to the dissolution of the secondary eutectic compounds. The measured corrosion current densities of Mg-10Gd-3Y-0.5Zr alloys in as-cast, T4, and T6 conditions are 36 μA?cm~(-2), 10 μA?cm~(-2), and 33 μA?cm~(-2), respectively. The proposed equivalent circuit [Rs(CPE_1(R_t(R_fCPE_2))] by Zview software matches well with the tested electrochemical impedance spectra(EIS) data.  相似文献   

6.
The corrosion characteristics of copper in magnetic action system were investigated by mass loss method, electrochemical test, scanning electron microscopy (SEM) and energy analysis. It is found that the corrosion process of copper is influenced by magnetic field. The flow corrosion rate of copper decreases at the initial segment, then drives to gentle stage at the final segment. From electrochemical test, the corrosion rate of copper in the magnetized sea water is minimal compared with that in 3.5% NaCl solution and sea water. Electlochemical impedance spectroscopy (EIS) plots of copper in 3.5% NaCl, sea water and magnetized sea water are similar. However, EIS plot of copper in magnetized sea water shifts rightwards due to the effect of magnetic field on sea water. The corrosion process of copper in magnetized sea water is pitting corrosion. The surfaces of samples are finer in magnetized sea water relative to those in 3.5% NaCl solution and sea water. The corrosion products of copper include large amount of Cu element, O element and Cl element. Cu2O and CuCl2 are the primary products. This suggests that electromagnetic treatment has remarkable effect on the corrosion of copper.  相似文献   

7.
The Zn-Mg alloys with Mg additions of 35%, 40% and 45%(mass fraction) were prepared by conventional casting method, with the aim to develop new biodegradable materials. The effects of cooling rate and composition on the microstructures, hardness and corrosion resistance were studied by XRD, SEM, microhardness and corrosion testing techniques. The corrosion behaviors of experimental alloys in simulated body fluids were analyzed. The results show that the amount of the petal-like MgZn2 phase decreases, as well as the hardness of the alloys, but that of the polygonal MgZn2 phase increases with the increase of Mg content when the cooling rate is constant. When the alloy composition is constant, the MgZn2 phase changes easily from petal-like to polygon, and the hardness decreases with the decrease of the cooling rate.  相似文献   

8.
The electrochemical behaviors of commercially pure titanium(CP Ti) and Co-Cr alloy in Ringer‘s solution have been investigated.The results indicate that the electric potential of passive region for CP Ti is up to 3000mV,and its passive current density is 3.078 μA/cm^2,The excellent corrosion resistance of CP Ti can be attributed to the formation of TiO2 oxide film.The passive region of Co-Cr alloy is 770mV,which is narrower than that of CP Ti.However,no hystersis loops are found in the reverse scanning curves of Cu-Cr alloy.A complex oxide film of Co3O4,Co2O3,and Cr2O3 formed on the surface provides Co-Cr alloy with a stable electrochemistry property.The corrosion rates of the crevice samples increase with the pH value of medium decreasing.The electron probe microanalyzer(EPMA) analysis indicates that Ti in CP Ti and Co,Cr in Co-Cr alloy dissolve in crevice area due to the Sealed-Cell effect.  相似文献   

9.
The preparation of copper arsenite with arsenic trioxide was presented and its application in the purification of copper electrolyte was proposed. The variables of n(OH^-)/n(As), n(Cu)/n(As), NaOH concentration, reaction temperature and pH value have some effects on the yield of copper arsenite. The optimum conditions of preparing copper arsenite are that the molar ratio of alkali to arsenic is 2:1, NaOH concentration is 1 mol/L, the molar ratio of copper to arsenic is 2:1, pH value is 6.0 and reaction temperature is 20℃. The yield of copper arsenite is as high as 98.65% under optimum conditions and the molar ratio of Cu to As in the product is about 5:4. The results of the purification experiments show that the removal rate of antimony and bismuth is 53.85% and 53.33% respectively after 20g/L copper arsenite is added. The purification of copper electrolyte with copper arsenite has the advantages of simple technique, good purification performance and low cost.  相似文献   

10.
The purification effects of Er addition in chloride flux during smelting on microstructure, tensile properties, and corrosion resistance of as-cast AZ80 D magnesium alloy were carried out. The results show that Er addition in the flux can eliminate the MgO inclusions and improve the tensile properties and corrosion resistance of the alloy. Using chloride flux mixed with 8.0 wt% Er, σb and δ of the as-cast AZ80 D magnesium alloy can be improved from 150 MPa and 2.1 % to the maximum value of 230 MPa and 4.8 %, respectively. Meanwhile, the corrosion rate decreases from 1.10 to 0.12 mg·(cm^2·d)^-1 in 5 wt% NaCl solution. However, with increasing Er content in chloride flux further, φ-(Al7ErMn5) and τ-(Al66.7Mg23.3Er10) phase are formed, and the morphology of γ-(Mg17Al12) phase is modified. The coarse φ-(Al7ErMn5)phase along dendrite boundaries decreases cohesion force between dendrites, which results in the worse of tensile properties.  相似文献   

11.
目的 化学机械抛光(CMP)包含化学腐蚀和机械磨削两方面,抛光液pH、磨粒粒径和浓度等因素均会不同程度地影响其化学腐蚀和机械磨削能力,从而影响抛光效果。方法 采用30~150 nm连续粒径磨粒抛光液、120 nm均一粒径磨粒抛光液、50 nm和120 nm配制而成的混合粒径磨粒抛光液,分别对蓝宝石衬底晶圆进行循环CMP实验,研究CMP过程中抛光液体系的变化。结果 连续粒径磨粒抛光液中磨粒大规模团聚,满足高材料去除率的抛光时间仅有4 h,抛光后的晶圆表面粗糙度为0.665 nm;均一粒径磨粒抛光液中磨粒稳定,无团聚现象,抛光9 h内材料去除率较连续粒径磨粒抛光液高94.7%,能至少维持高材料去除率18 h,抛光后的晶圆表面粗糙度为0.204 nm;混合粒径磨粒抛光液初始状态下磨粒稳定性较高,抛光9 h内材料去除率较连续粒径磨粒抛光液高114.8%,之后磨粒出现小规模团聚现象,后9 h材料去除率仅为均一粒径磨粒抛光液的59.6%,18 h内材料去除率仅为均一粒径磨粒抛光液的87.7%,但抛光后的晶圆表面粗糙度为0.151 nm。结论 一定时间内追求较高的材料去除率和较好的晶圆表面粗糙度选用混合粒径磨粒抛光液,但需要长时间CMP使用均一粒径磨粒抛光液更适合,因此,在工业生产中需要根据生产要求配合使用混合粒径磨粒抛光液和均一粒径磨粒抛光液。  相似文献   

12.
目的研究抛光液pH值、温度和浓度对化学机械抛光蓝宝石去除率的影响,以提高抛光效率。方法采用CP4单面抛光试验机对直径为50.8 mm C向蓝宝石晶元进行化学机械抛光,通过电子分析天平对蓝宝石抛光过程中的材料去除率进行了分析,采用原子力显微镜(AFM)对蓝宝石晶元抛光前后的表面形貌和粗糙度(Ra)进行了评价。结果蓝宝石在化学机械抛光过程中的材料去除率均随抛光液pH值和温度的升高呈先增大后减小趋势。当抛光原液与去离子水按1:1的体积比混合配制抛光液,KOH调节pH值为12.2,水浴加热抛光液35℃时,蓝宝石抛光的材料去除率(MRR)达到1.119μm/h,Ra为0.101 nm。结论随着pH的增大,化学作用逐渐增强,而机械作用逐渐减弱,在pH为12.2的时候能达到平衡点,此时的MRR最佳;随着温度的升高,化学作用逐渐增强,而机械作用保持不变,抛光液温度为35~40℃时,化学作用与机械作用达到平衡,MRR最佳,当温度高于40℃后,抛光液浓度明显增大,而过高的浓度会导致MRR的减小。抛光液的相关性能优化后,化学机械抛光蓝宝石的MRR较优化前提高了71.4%。  相似文献   

13.
Recently, many researchers have studied the material removal mechanism of copper chemical mechanical planarization (CMP). On the basis of their previous works, we studied the mechanical effect of copper (Cu) CMP on the material removal rate profile. Copper CMP was performed using citric acid (C6H8O7), hydrogen peroxide (H2O2), colloidal silica, and benzotriazole (BTA, C6H4N3H) as a complexing agent, an oxidizer, an abrasive, and a corrosion inhibitor, respectively. In this paper, the abrasives and process condition are main mechanical factors of CMP. The colloidal silica, used as an abrasive in copper CMP slurry containing 0.01 M citric acid and 3 vol% hydrogen peroxide, controlled the wafer edge profile by abrading the wafer edge. The polishing pressure did not contribute to the material removal rate (MRR) profile, but did to the MRR. As the rotational velocity of the polishing head and table increased, the deviation of MRR profile became smaller. The results of this paper showed that the abrasive concentration was the key factor which controlled the wafer edge profile, and also the rotational velocity was the key factor which controlled wafer center profile of MRR.  相似文献   

14.
段世祥  吕冰海  邓乾发 《表面技术》2022,51(11):337-346, 384
目的 采用剪切增稠抛光方法对K9玻璃进行抛光,以工件表面粗糙度Sa为评价指标,研究不同磨粒抛光液对K9玻璃的抛光效果。方法 采用金刚石、CeO2、Al2O3和SiO2等4种单一磨粒,以及金刚石+SiO2混合磨粒,制备了不同的剪切增稠抛光液,并测试其流变特性。以?20 mm K9玻璃圆片为工件,首先在相同磨粒浓度下,进行4种单一磨粒抛光液的抛光实验,观测在抛光时间不同时工件表面粗糙度Sa的变化情况,比较4种抛光液的抛光效果。然后,对比CeO2抛光液与金刚石+SiO2混合磨粒抛光液的抛光效果,并分析讨论混合磨粒抛光液的材料去除过程。结果 使用CeO2抛光液抛光35 min后,将工件的表面粗糙度Sa从(233.1±15.2)nm降至(1.6±0.2)nm;金刚石抛光液次之,在抛光55 min后工件的表面粗糙度Sa达到(1.86± 0.2)nm;Al2O3抛光液的效果相对最差。采用SiO2(质量分数10%)+金刚石(质量分数5%)抛光液,在抛光5 min后工件的表面粗糙度Sa比CeO2抛光液的低53.3%;在抛光35 min后,工件的表面粗糙度Sa从(230.7±10.5)nm降至(1.43±0.9)nm。在金刚石(质量分数5%)抛光液中添加不同浓度SiO2磨粒的抛光实验中发现,在抛光初始阶段,抛光效率随着SiO2磨粒浓度的增加而增大。结论 CeO2抛光液和SiO2(质量分数10%)+金刚石(质量分数5%)抛光液的抛光效果相对最优,后者在低表面质量时的抛光效率更高。  相似文献   

15.
路家斌  熊强  阎秋生  王鑫  廖博涛 《表面技术》2019,48(11):148-158
目的为了探究紫外光催化辅助抛光过程中,化学反应速率对SiC化学机械抛光的影响规律。方法通过无光照、光照抛光盘和光照抛光液3种光照方式,研究紫外光催化辅助作用对单晶SiC抛光过程中材料去除率的影响。测量不同条件下光催化反应过程中的氧化还原电位(ORP)值,来表征光催化反应速率,并进行了单晶SiC的紫外光催化辅助抛光实验,考察光催化反应速率对抛光效果的影响规律。结果实验表明,引入紫外光催化辅助作用后,材料去除率提高14%~20%,随着材料去除率的增加,光催化辅助作用对材料去除率的影响程度变小。光照射抛光液方式的材料去除率明显高于光照射抛光盘。不同条件下的抛光结果显示,化学反应速率越快,溶液的ORP值越高,材料去除率越大,表面粗糙度越低。在光照抛光液、H_2O_2体积分数4.5%、TiO_2质量浓度4 g/L、光照强度1500 mW/cm~2、pH=11的条件下,用W0.2的金刚石磨料对SiC抛光120 min后,能够获得表面粗糙度Ra=0.269 nm的光滑表面。结论在单晶SiC的紫外光催化辅助抛光过程中,光催化反应速率越快,溶液ORP值越高,抛光效率越高,表面质量越好。在H_2O_2浓度、TiO_2浓度、光照强度、pH等4个因素中,对抛光效果影响最大的是H_2O_2浓度,光照强度主要影响光催化反应达到稳定的时间。  相似文献   

16.
用游离磨料对圆光栅玻璃表面进行了研磨抛光实验,讨论了磨粒尺寸、磨料质量分数、加工时间、研磨盘转速、加载压力、抛光垫材料对试件表面粗糙度和材料去除率的影响。研究表明,硬质抛光垫能更好地保持试件的平面度。获得的优化工艺参数组合为:研磨盘转速75r/min;磨料质量分数10%;研磨液流量10mL/min;5μm的Al2O3加载压力0.019MPa,粗研20min;1μm的Al2O3加载压力0.015MPa,精研20min;30nm的CeO2加载压力0.012MPa,精抛10min。在该工艺组合下,获得了表面粗糙度值Ra为3.3nm、平面度为5μm的圆光栅玻璃。  相似文献   

17.
目的提高Co在超大规模集成电路全局化学机械抛光过程中的去除速率及Co/Ti去除选择比,并对去除机理进行详细描述。方法研究不同浓度的磨料、多羟多胺络合剂(FA/OII)、氧化剂等化学成分及不同pH值对钴去除率的影响。利用电化学实验、表面化学元素分析(XPS)揭示钴实现高去除速率的机理,通过原子力显微镜(AFM)对钴抛光前后的表面形貌进行了观察,并采用正交实验法找到抛光液最佳组分配比。结果随磨料浓度的升高,钴去除速率增大。随pH值的升高,钴去除速率降低。随氧化剂浓度的提升,钴去除速率升高,但Co/Ti去除选择比先升后降。随螯合剂浓度的增大,钴去除速率及Co/Ti去除选择比均先升后降。正交试验找到了最佳的抛光液配比及条件(3%磨料+20 mL/L多胺螯合剂(FA/OⅡ)+5 mL/L氧化剂(H_2O_2),pH=8),实现了钴的高去除(~500 nm/min)及较好的Co/Ti去除选择比(100:1)。并且,表面的平坦化效果明显提高,原子力显微镜测试结果显示Co面粗糙度由原本的3.14 nm降低到0.637 nm。结论采用弱碱性抛光液能有效提升钴的去除速率,并保证腐蚀可控。抛光液中同时含有氧化剂和螯合剂时,通过强络合作用实现了钴的抛光速率和Co/Ti去除选择比的大幅度提升。  相似文献   

18.
(锇有可能作为大规模集成电路铜互连扩散阻挡层新材料.)利用自制的抛光液对金属锇片进行抛光,研究在双氧水-磷酸体系抛光液中H2O2浓度和抛光液pH值对抛光速率的影响.结果表明,当抛光液中主要成分仅为氧化剂H2O2时,并不能在金属锇表面达到好的腐蚀效果.在磷酸体系抛光液中,H2O2能够通过促进阴极反应的进行从而增强抛光液对金属锇的化学作用;低浓度H2O2通过增强抛光液对金属锇的化学腐蚀能力,从而增加了抛光速率值:较高浓度H2O2的加入对抛光速率值影响较小.H3PO4能够在抛光液中起到抑制剂、pH调节剂和络合剂的作用.当抛光液pH值为4.0时,金属锇表面生成的钝化膜最致密.当pH值为4.0或5.0时,金属锇表面生成的钝化膜OCP值大于金属锇的OCP值,且此条件下的抛光速率值较高.  相似文献   

19.
许宁徽  李薇薇  钱佳  孙运乾 《表面技术》2022,51(12):277-284, 319
目的 探究不同配比方案配制pH值相同的抛光液对抛光去除速率、抛光液寿命和表面粗糙度的影响,优化硅衬底晶圆抛光液,使其满足半导体产业的发展要求。方法 以二氧化硅水溶胶为磨料,通过设置有机碱、pH缓冲剂、pH稳定剂的不同配比来调节和稳定抛光液的初始pH值(11.0~12.0),在最佳工艺参数下循环使用抛光液对2英寸(1英寸≈2.54 cm)硅衬底晶圆进行抛光实验。研究不同配比下抛光液pH值、抛光去除速率随抛光液循环使用时间的变化情况。对比实验结果,分析各种成分在抛光过程中的作用,以及对抛光效果产生的影响,得出最佳配比方案,优化抛光液方案。结果 通过优化硅衬底晶圆的抛光液方案,使抛光去除速率达到0.804 μm/min,抛光液的寿命延长了约114.29%,抛光后硅衬底晶圆的表面粗糙度最低为0.156 nm。结论 得到了抛光液的最佳配比方案,有机碱的质量分数为1.0%,pH缓冲剂的质量分数为1.1%,并加入pH稳定剂调节pH,使其抛光去除速率、抛光液寿命、表面粗糙度都得到很大提升。  相似文献   

20.
Mechano-chemical polishing of silicon wafers   总被引:2,自引:0,他引:2  
Rapid progress in recent IC fabrication industry has increased the demand of tight specification of non-uniformity (NU) and surface polishing in silicon wafer planarization. Chemical–mechanical polishing (CMP) is currently the most popular method for IC wafer planarization. However, the sub-surface damage problem caused by hard abrasives and chemical waste problem of CMP have decreased the throughput and increased the cost of IC fabrication. This study is to investigate the mechano-chemical polishing (MCP) of silicon wafers by slurry of soft abrasives, BaCO3 and through experiments to verify that the solid phase chemical reaction (SPCR) is the main reaction process involved in MCP. A planarization mechanism with compliance has been designed and tested through MCP experiments. Experimental results of MCP of silicon wafers have achieved the average of surface roughness improvement ratio (SRIR) to 99% and the surface roughness Ra=0.633 nm measured by atomic force microscope (AFM). The material removal rate (MRR) has been calculated and the significant influence of slurry weight percent and polishing pressure have been found. The NU has also been estimated for evaluation of MCP parameters. The sub-surface damage of silicon wafer has not yet been found in experimental results and hence the MCP process of silicon wafers has been verified to become a green or environment-friendly technology of silicon wafer planarization.  相似文献   

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