Studies and Application of Auger Monitoring System for Quality Control and Assurance of Al Bondpads

Author(s):  
Hua Younan

Abstract In wafer fabrication (Fab), Fluorine (F) based gases are used for Al bondpad opening process. Thus, even on a regular Al bondpad, there exists a low level of F contamination. However, the F level has to be controlled at a lower level. If the F level is higher than the control/spec limits, it could cause F-induced corrosion and Al-F defects, resulting in pad discoloration and NSOP problems. In our previous studies [1-5], the theories, characteristics, chemical and physical failure mechanisms and the root causes of the F-induced corrosion and Al-F defects on Al bondpads have been studied. In this paper, we further study F-induced corrosion and propose to establish an Auger monitoring system so as to monitor the F contamination level on Al bondpads in wafer fabrication. Auger monitoring frequency, sample preparation, wafer life, Auger analysis points, control/spec limits and OOC/OOS quality control procedures are also discussed.

Author(s):  
Hua Younan ◽  
Nistala Ramesh Rao ◽  
Ng Adrian ◽  
Tsai Tony

Abstract Non-stick on pad (NSOP) is a yield limiting factor that can occur due to various reasons such as particle contamination, galvanic corrosion, Fluorine-induced corrosion, process anomalies, etc. The problem of NSOP can be mitigated through a careful process characterization and optimization. In this paper, a bondpad qualification methodology (OSAT) will be discussed. It will be argued that by employing different physical analysis techniques in a failure analysis of wafer fabrication, it is possible to perform comprehensive characterization studies of the Aluminum bondpad so as to develop a robust far backend of line process. A good quality Al bondpad must meet the following four conditions-OSAT: (i) it should be no discoloration (using Optical inspection); (ii) should be defect free (using SEM inspection); (iii) should be with low contamination level (such as fluorine and carbon contamination should be within a control limit) (using Auger analysis) and (iv) should have a protective layer on bondpad surface so as to prevent bondpad corrosion (using TEM).


Author(s):  
Ng Sea Chooi ◽  
Chor Theam Hock ◽  
Ma Choo Thye ◽  
Khoo Poh Tshin ◽  
Dan Bockelman

Abstract Trends in the packaging of semiconductors are towards miniaturization and high functionality. The package-on-package(PoP) with increasing demands is beneficial in cost and space saving. The main failure mechanisms associated with PoP technology, including open joints and warpage, have created a lot of challenges for Assembly and Failure Analysis (FA). This paper outlines the sample preparation process steps to overcome the challenges to enable successful failure analysis and optical probing.


1974 ◽  
Vol 20 (4) ◽  
pp. 502-504 ◽  
Author(s):  
Daniel M Baer

Abstract Several technical difficulties diminish the usefulness of serum triglyceride estimation by the method of Stone and Thorp [Clin. Chim. Acta 14, 812 (1966)]. An artificial and somewhat unstable material is used in the standardization. Falsely elevated readings caused by scratched cuvettes are a frequent problem. Conventional quality-control procedures cannot be used because stable preparations are not available. Specimen stability is a greater problem than with conventional chemical methods. In spite of these difficulties, the method can be useful, if its limitations are recognized, in measurements made on nonfasting individuals.


2012 ◽  
Vol 500 ◽  
pp. 715-720
Author(s):  
Jian Guang Li ◽  
Jian Ding ◽  
Huai Jing Jing ◽  
Ying Xue Yao

Accuracy of the Stewart parallel manipulator is utmost important in assembly quality control procedures, and it's also difficult to demonstrate the inner relations quantitatively between errors of pose and of actuators. A novel methodology is proposed in this paper. Firstly the experiment area planning approach is proposed according to the pose and strut symmetries of the manipulator, and the uniform experiment design is conducted to investigate indexes of accuracy sensitivity. The regression equations are established to analyze the significance of various factors according to experiment results.


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