铜互连电镀中有机添加剂的合成与分析

铜互连是保障电子设备的功能、性能、能效、可靠性以及制备良品率至关重要的一环。铜互连常通过在酸性镀铜液电镀铜实现,并广泛用于芯片、封装基材和印制电路板中。其中,有机添加剂在调控铜沉积完成沟槽填充、微孔填充以形成精密线路和实现层间互连方面起着决定性作用。添加剂主要由光亮剂、抑制剂和整平剂三组分组成,在恰当的浓度配比下,添加剂对于盲孔超级填充具有协同作用。目前,已报导的文献聚焦于代表性添加剂的超填充机理及其电化学行为,而对于添加剂的化学结构与制备方法鲜有深入研究。本文重点研究了各添加剂组分的制备工艺和快速电化学筛选方法,为电镀铜添加剂的未来发展提供理论指导。

SGK3 overexpression correlates with a poor prognosis in endoscopically resected superficial esophageal squamous cell neoplasia:A long-term study

BACKGROUND The expression status of serum and glucocorticoid-induced protein kinase 3(SGK3)in superficial esophageal squamous cell neoplasia(ESCN)remains unknown.AIM To evaluate the SGK3 overexpression rate in ESCN and its influence on the prognosis and outcomes of patients with endoscopic resection.METHODS A total of 92 patients who had undergone endoscopic resection for ESCN with more than 8 years of follow-up were enrolled.Immunohistochemistry was used to evaluate SGK3 expression.RESULTS SGK3 was overexpressed in 55(59.8%)patients with ESCN.SGK3 overexpression showed a significant correlation with death(P=0.031).Overall survival and disease-free survival rates were higher in the normal SGK3 expression group than in the SGK3 overexpression group(P=0.013 and P=0.004,respectively).Cox regression analysis models demonstrated that SGK3 overexpression was an independent predictor of poor prognosis in ESCN patients(hazard ratio 4.729;95% confidence interval:1.042-21.458).CONCLUSION SGK3 overexpression was detected in the majority of patients with endoscopically resected ESCN and was significantly associated with shortened survival.Thus,it might be a new prognostic factor for ESCN.

Microstructure evolution,mechanical properties and tailoring of coefficient of thermal expansion for Cu/Mo/Cu clad sheets fabricated by hot rolling

The law of microstructure evolution and mechanical properties of hot roll bonded Cu/Mo/Cu clad sheets were systematically investigated and the theoretical prediction model of the coefficient of thermal expansion(CTE)of Cu/Mo/Cu clad sheets was established successfully.The results show that the deformation of Cu and Mo layers was gradually coherent with an increase in rolling reduction and temperature and excellent interface bonding was achieved under the condition of a large rolling reduction.The development of the microstructure and texture through the thickness of Cu and Mo layers was inhomogeneous.This phenomenon can be attributed to the friction between the roller and sheet surface and the uncoordinated deformation between Cu and Mo.The tensile strength of the clad sheets increased with increasing rolling reduction and the elongation was gradually decreased.The CTE of Cu/Mo/Cu clad sheets was related to the volume fraction of Mo.The finite element method can simulate the deformation and stress distribution during the thermal expansion process.The simulation result indicates that the terminal face of the clad sheets was sunken inward.

Artificial neural network potential for gold clusters

In cluster science, it is challenging to identify the ground state structures(GSS) of gold(Au) clusters. Among different search approaches, first-principles method based on density functional theory(DFT) is the most reliable one with high precision. However, as the cluster size increases, it requires more expensive computational cost and becomes impracticable.In this paper, we have developed an artificial neural network(ANN) potential for Au clusters, which is trained to the DFT binding energies and forces of 9000 Au N clusters(11 ≤ N ≤ 100). The root mean square errors of energy and force are 13.4 meV/atom and 0.4 eV/A, respectively. We demonstrate that the ANN potential has the capacity to differentiate the energy level of Au clusters and their isomers and highlight the need to further improve the accuracy. Given its excellent transferability, we emphasis that ANN potential is a promising tool to breakthrough computational bottleneck of DFT method and effectively accelerate the pre-screening of Au clusters’ GSS.

Interventional radiology followed by endoscopic drainage for pancreatic fluid collections associated with high bleeding risk: Two case reports

BACKGROUND Endoscopic ultrasound(EUS)-guided transluminal drainage is an advanced technique used to treat pancreatic fluid collections(PFCs). However, gastric varices and intervening vessels may be associated with a high risk of bleeding and are, therefore, listed as relative contraindications. Herein, we report two patients who underwent interventional embolization before EUS-guided drainage.CASE SUMMARY Two 32-year-old males developed symptomatic PFCs after acute pancreatitis and came to our hospital for further treatment. One patient suffered from intermittent abdominal pain and vomiting, and computed tomography(CT) imaging showed an encapsulated cyst 7.93 cm × 6.13 cm in size. The other patient complained of a mass inside the abdomen, which gradually became enlarged. Gastric varices around the ideal puncture site were detected by EUS when we evaluated the possibility of endoscopic drainage in both patients. Interventional embolization was recommended as the first procedure to decrease the risk of bleeding. After that, EUS-guided transluminal drainage was successfully conducted, without vascular rupture. No postoperative complications occurred during hospitalization, and no recurrence was detected at the last follow-up CT scan performed at 1 mo.CONCLUSION Interventional embolization is a safe, preoperative procedure that is performed before EUS-guided drainage in PFC patients with gastric varices or at high risk of bleeding.