The interdiffusion and subsequent compound formation was investigated in thin film couples of Ti–Au, Ti–Pd, and Ti–Pt using transmission and glancing angle electron diffraction techniques. Aging temperatures up to 500°C and times up to 8 h were considered. For all three couples, intermetallic compound formation was observed in the as-deposited films indicating substantial diffusion during deposition (= 100–150°C). For the Ti–Au couples, the TiAu2, TiAu, and Ti3Au compounds formed during diffusion. For the Ti-Pd and Ti-Pt couples the isostructural compounds TiPd, TiPt and Ti3Pd, Ti3Pt were observed. After the formation of the Ti3Pd type compound diffusion ceased for temperatures <500°C indicating that this compound was acting as a diffusion barrier. In all cases Ti was found to be the fastest diffusing species, where it was observed that the diffusion occurred principally through the Au, Pd, or Pt grain boundaries. The effective diffusion coefficient was estimated to be about 105 times larger than expected for bulk diffusion. The role of diffusion in the formation of compounds and the role of film defects in determining the effective diffusion coefficients are discussed.

Silicon nitride films deposited on silicon substrates by several techniques were studied. Electron diffraction studies of the films revealed that films varied in crystallite size from <10 to ∼100Aå. Radiotracer diffusion experiments using Na22 as diffusant revealed that the smaller crystallite films were better barriers to sodium diffusion than the larger crystallite films. Field enhanced drift of sodium was not observed in any of the silicon nitride films regardless of crystallite size. Silicon nitride films composed of large crystallites appeared to etch faster than smaller crystallite films in dilute buffered hydrofluoric acid.

When gold surfaces are prepared by polishing with alumina abrasives, the contact angles of water on these surfaces are found to be 34r-56°, even after some of the surface has been removed by etching with aqua regia. Reflection electron diffraction patterns on these surfaces show evidence of residual abrasive material on the surface which is not removed by etching. Gold that is smoothed by compression between smooth surfaces of aluminum, stainless steel, or mica shows water contact angles in the same range of values, with electron diffraction patterns showing the presence of alumina, iron oxide, and muscovite, respectively, on the surfaces. When gold surfaces are prepared by vacuum evaporation of high-purity metal on silica substrates or by polishing of gold with diamond abrasive followed by firing in oxygen at 1000°, the contact angles of water on these surfaces are 55-65°. The electron diffraction patterns show no contaminating oxide material. These results show that the presence of hydrophilic inorganic contaminants on surfaces can affect wettabilities as seriously (but in the opposite direction) as the more commonly discussed contamination by hydrophobic organic material.

A high speed, LSI, n-channel Si-Gate technology has been developed and characterized for the manufacture of integrated circuits. Utilizing the advantages of local oxidation and ion implantation, a technology is achieved which is: (a) fabricated on high resistivity Si substrates; (b) quasi-planar in topological structure; (c) completely adjustable in gate threshold voltage (enhancement and depletion modes) and field threshold voltage; and (d) highly reproducible in electrical parameter control. Additionally, by employing a thin gate insulator structure (sio2, 75d) a factor of increase in gain is realized with respect to standard p-channel MOSFETs. 4,096 bit dynamic RAM circuits have been designed and fabricated in this technology. Typical access times of $50 nanoseconds with high circuit yields are realized.

The application of Pt or P d silicides in silicon device technologies stimulated interest in the crystallography and kinetics of compound formation between thin films of Pt or P d and bulk Si. Electron transmission observations of Pt-Si diffusion couples showed t h a t three compounds were formed during diffusion: Pt,Si, Pt,Si, and PtSi. The Pt,Si compound formed initially, followed by the formation of Pt,Si and PtSi. The Pt,Si compound disappeared as diffusion proceeded. The resulting film was found to be a two phase mixture of approximately 35 t o 40% Pt,Si and remainder PtSi. Long time annealing a t 650 "C resulted in no detectable changes from the two phase mixture. I n Pd-Si diffusion couples the dominant phase is Pd,Si with only small amounts of PdSi formed after vacuum annealing. In both cases it was concluded that the transformation to the PdSi or PtSi compound is determined by the kinetics of the transformation mechanism and not by the thermodynamic stability. F u r die Anwendung von Platin-oder Palladium-Siliziden in Silizium-Bauelementen ist die Untersuchung der Struktur und der Kinetik der Verbindungsbildung zwischen dunnen Schichten von Platin oder Palladium und dickem Silizium von Interesse. Mit Hilfe von Elektronenbeugung und Elektronenmikroskopie von Pt-Si-Proben konnte gezeigt werden, da13 drei Verbindungen, Pt,Si, Pt,Si und PtSi, wahrend des Diffusionsprozesses gebildet werden. Die Pt,Si-Phase wird im Anfangsstadium der Diffusionsprozesse gebildet, bei weiterem Tempern wird die Pt,Si-Phase abgebaut, wahrend die Pt,Si-und PtSi-Verbindungen auftreten. Die resultierende Schicht besteht aus ungefahr 35 bis 40% Pt,Si und 60 bis 65% PtSi. Langes nachtragliches Tempern bei 650 "C verursachte keine Anderung des Volumenverhaltnisses der zwei Phasen. I m Falle von Pd-Si-Proben wurde die Pd,Si-Verbindung als vorherrschende Phase gefunden. Die PdSi-Verbindung war nur in Spuren als Folge des Temperns im Vakuum vorhanden. Daraus kann geschlossen werden, daB in beiden Fiillen die Umwandlung in die PtSi-oder PdSi-Verbindung durch die Kinetik des Uqwandlungsmechanismus und nicht durch thermodynamische Stabilitat bestimmt ist.