Failures semiconductor device

A novel method of improving the reliability of plastic packaged semiconductor devices has been developed. One of the major causes of failure in such devices is corrosion due to moisture permeating through the encapsulant, transporting small amounts of ionic impurity and condensing at the chip surface to form an aggressive electrolyte. 

A reliability concern with semiconductor devices, such as chip transistors in which one of the connections is made through the backside metallization by attaching with either eutectic alloy or conductive epoxy, is the loss of backside ohmic contact. Loss of ohmic contact may be due either to mechanical/physical or chemical mechanisms. Mechanical failures occur from partial or complete delamination of the adhesive interface. The smooth surface of the die metallization contributes to the problem whereas roughening the surface improves results. Loss of contact is evident from increases in resistance during initial electrical testing, but may better be detected... 

In this paper our task is to determine the average lifetime t of the semiconductor devices at functioning temperature. There is applied the Arrhenius model while considering that the lifetime to failure at a temperature is proportional with the rate of the chemical degradation reaction, which takes place at that temperature. The equation of Arrhenius for the lifetime may be written as follows ... 

We apphed this method on three lots of semiconductor device having adequate dimensions, and the time of failure occurrences is observed. 

Based on hypothesis H confirmation the researchers on semiconductor field are interested in knowing the activation energy. The second phase of the aging research consists in determining the activation energy characteristic to the evidenced failure mechanism for this type of semiconductor device. 

Baku, Floarea.2000. Doctor s Degree Thesis Contribution to the study of failure mechanisnts of semiconductor devices under accelerated aging. University of Bucharest. 

The damage thresholds for equipment containing semiconductor devices and other semiconductor components vary for device types and, due to physics-of-failure parameter differences, for otherwise identical parts (Corbin et al. 1982). Several equipment items are often needed to support an operational function (control system devices, measurement devices, etc.). In this case, the probabilities of equipment failure must... 

One of the main causes of failure in semiconductor devices is particles sticking to the surface, shorting out the conductor lines. Some of these contaminant particles arise from the wafer polishing operations needed to produce flat surfaces with roughness less than 1 nm. The polishing process is shown schematically in Fig. 13.12. 

Cook, J. P. and Servais, G. E., "Corrosion Failures in Semiconductor Devices and Electronic Systems, Proceedings of the Automotive Corrosion and Prevention Conference, SAE P-136, Warrendale, PA, 1983. 

Rdiability of semiconductor devices is determined by two considerations. The first one is early failures, usually caused by fluctuations in production, and the second one is fatigue, related to package design. Accelerated tests are necessa to detect those failures earlier. Many test methods have been proposed for development and assurance on the manufacturer s side and for incoming inspection on the user s... 

Also, avoid dry conditions to prevent static electricity problems. Static electricity applied directly to module or circuit terminals can cause erratic control operation and, in some instances, can produce voltage breakdown failures in semiconductor devices. 

The applications of semiconductors materials are discussed in Volume 2. The various topics on semiconductor devices include Si/GeSi heterostructures for Si-based nanoelectronics, impact ionization in compound semiconductor devices, quantum dot optoelectronic devices, failure mechanisms in compound semiconductors, electron devices, semiconductor quantum materials and their applications in electronics and optoelectronics, and photoelectromotive force effects in semiconductors. 

The temperarnre dependent acceleration factor % for 2 failure mechanisms (e.g. for discrete semiconductor devices, IC s, optoelectronic components...) are stated in DIN EN 61709 or SN 29500 as foUows ... 

Anion contamination can have a corrosive and or etching effect on semiconductor devices during the fabrication that can result in immediate or future device failure. Evaporation of solutions eontaining anions may leave surface residues. Anions ean also originate in the process chemicals or leach out of plastic parts. Anions are measured by Ion Chromatography. 

Heating is used to alloy the deposited material with the substrate surface. Post-deposition diffusion and reaction can form a more extensive interfacial region and induce compound formation in semiconductor metallization (Figure 9.3). Post-deposition heating and diffusion can be used to completely convert the deposited material to interfacial material. For example, a platinum film on silicon can be heated to form a platinum silicide layer. The diffusion at the interface can be studied by the motion of markers. Post-deposition interdiffusion can result in the failure of a metallized semiconductor device by diffusion and shorting of the junctions. Diffusion can be hmited by using diffusion barriers. Heating plus isostatic pressure may be used to remove voids in semiconductor metallization. 

RAC publications include data summaries for specific component types, such as hybrid microcircuits, small, medium and large-scale integration digital devices, linear and interface devices, digital monolithic devices, and discrete semiconductors. In addition, there are reliability and equipment maintenance data books that provide the failure and repair time data on military electronic equipment by application such as subsystem. 

The acoustic microscopy s primary application to date has been for failure analysis in the multibillion-dollar microelectronics industry. The technique is especially sensitive to variations in the elastic properties of semiconductor materials, such as air gaps. SAM enables nondestructive internal inspection of plastic integrated-circuit (IC) packages, and, more recently, it has provided a tool for characterizing packaging processes such as die attachment and encapsulation. Even as ICs continue to shrink, their die size becomes larger because of added functionality in fact, devices measuring as much as 1 cm across are now common. And as die sizes increase, cracks and delaminations become more likely at the various interfaces. 

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