MOS Integrated Circuit Reliability

This paper presents information on the reliability of MOS integrated circuits based on p-channel enhancement-mode transistors, and describes their failure modes and mechanisms. The principal failure mechanisms were ion migration at the surface and oxide shorting. The results of experimental studies of the effects of variations in construction, processing, and levels of stress are presented, and are compared with other available information on MOS integrated circuit reliability. The failure rate for commercially available complex MOS arrays is on the order of 0.001 to 0.01 per 1000 h of operating life at 125°C for arrays containing approximately 600 p-channel transistors. This corresponds to a failure rate on the order of 5 × 10?6 to 5 × 10?5 per equivalent gate per 1000 h. The effects of device complexity, operating temperature, and other factors are discussed. A reliability prediction equation for MOS integrated circuits is derived from available information. An overall activation energy for functional failure mechanisms of approximately 5 kcal/mole (?0.2 eV/molecule) is considered applicable to typical MOS integrated circuits. Thus, the failure rate of MOS devices operated at 50°C ambient temperature can be predicted to be on the order of 10?6 to 10?5 per equivalent gate per 1000 h.     

Beitrag zur Abschätzung der Kriechriβeinleitung in fehlerbehafteten Bauteilen

Versuche zur Bestimmung des makroskopischen Kriechanrisses. Unterscheidung der Versagensarten: Riβspitzenschädigung –Ligamentschädigung. Auswertung betriebsbeanspruchter Guβstücke mit Herstellungsfehlern. Vergleich der Bauteilbefunde mit den Laborergebnissen mit Hilfe der fiktiv elastischen Spannungsintensität K_lid des Anfangsrisses und der Nennspannung σ_n im Fernfeld des Risses. Zusammenhang üblicher Kriechdaten (R_mt und A_u) mit der Spannungsintensität K_lid für Kriechriβeinleitung.     

Assessing heat-affected zone properties of pressure vessel weldments using simulation techniques

This paper describes simulation methods for mechanisms occurring in the coarse grain heat affected zone (HAZ) of thick-walled weldments. The simulation process is divided into overheating simulation and simulation of stress-relief heat treatment. Overheating simulation is mainly practised by inductive or conductive heating and produces an HAZ-representative microstructure. For the stress-relief heat treatment simulation, annealing tests and constant load creep tests at stress-relief temperatures are carried out.Classifications in order of crack sensitivity and service-suitability are proposed. The order of crack sensitivity is derived from the magnitude of deformability and creep resistance in constant load creep tests. The order of service-suitability is based on the results of notch-impact tests (ISO-V) and tensile tests subsequent to both simulation treatments. The techniques are demonstrated on an example of an ASTM A 508 CI 2 (22 NiMoCr 37) plate material.     

Improving the uniformity in combustion-synthesized titanium carbide

The effects of reactant dispersion and outgassing on the microstructure of combustion-synthesized TiC were investigated. Pressure filtration casting of Ti+C colloidal suspension was shown to be an effective reactant dispersion method to improve the homogeneity of the product. The relation between the nature of the outgassing atmosphere and the formation of titanium oxide and precombustion titanium carbide was investigated. The combination of the colloidal dispersion technique with outgassing was shown to provide TiC products with reduced defects and improved microstructure.     

Darstellung von Poly-4-hydroxystyrol und dessen Umsetzung zu einem Chelataustauscher auf Basis o-(2-Hydroxyphenylazo)benzoesäure. Chelatbildende Austauscherharze,VIII

The radical pearl-copolymerization of 4-acetoxystyrene in the presence of divinylbenzene yields cross-linked poly-4-acetoxystyrene which can be carefully hydrolized to poly-4-hydroxystyrene. Poly-4-hydroxystyrene reacts with diazocompounds to chelate forming polymers with o,o′-disubstituted azo-groups. The synthesis of a chelating resin based on o-(2-hydroxyphenylazo)benzoic acid is described.     

Current capabilities and limitations of available stereological techniques

The various methods available for stereological analysis of sectioned material are reviewed with special emphasis on a critical evaluation of their capabilities, advantages and limitations. The review deals with four main topics: (I) Comparison with structural standards; (II) Point counting methods; (III) Image analysis with the scanning microphotometer; (IV) Automatic image analysis based on television systems. It is concluded that each of these approaches has its place, and that the choice essentially depends on the properties of the material and on the nature of the problem.