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Thin silicon nitride films ͑less than 20 nm͒ deposited on ͑100͒ silicon substrates via low pressure chemical vapor deposition ͑LPCVD͒ at three temperatures ͑730, 760, and 825°C͒ were analyzed by spectroscopic ellipsometry ͑SE͒, attenuated total reflection ͑ATR͒, and other tools. Films appeared to have similar optical bandgaps ͑ϳ5 eV͒, and the values decreased slightly with the higher deposition temperature. Second ionic mass spectroscopy results showed that a similar amount of oxygen exists in the interface between silicon and silicon nitride. ATR spectra showed no sign of Si-H bonds and decreasing N-H bonds at higher deposition temperature in the thin films. The electrical properties of the films are also discussed.Silicon nitride films have been widely used in very large scale integration ͑VLSI͒ technologies, such as diffusion mask, passivation, antireflection coatings, and gate dielectrics. 1-4 Various processing methods of silicon nitride films were reported, such as thermal nitridation, 5 atmospheric pressure chemical vapor deposition ͑CVD͒, 6 plasma-enhanced CVD ͑PECVD͒, 7 hot wall CVD ͑HWCVD͒, 8 and low pressure CVD ͑LPCVD͒. 9 Among the fabrication techniques, LPCVD is commonly chosen. Even though LPCVD nitride films cannot be used for gate dielectrics due to their poor interface quality and high bulk trap density, they are widely chosen for applications such as diffusion mask, nitride spacers, etc. We studied the LPCVD silicon nitride thin films deposited by using a mixture of dichlorosilane ͑DCS͒ and ammonia (NH 3 ) with nitrogen as dilute at three temperatures in a conventional batch reactor.The purpose of this work was to analyze the optical properties of thin to ultrathin ͑below 10 nm͒ silicon nitride films via spectroscopic ellipsometry ͑SE͒ analysis and directly study the bond structure ͑es-pecially bonds with hydrogen such as Si-H and N-H͒ of the films by attenuated total reflection ͑ATR͒. SE is a nondestructive optical technique used to determine the optical properties of substrates and thin films based on measuring the polarization ellipse of a light beam reflected off a sample at a given angle. From this data, the complex index of refraction and film thickness can be determined using a computer model fit. ATR provides a way of directly analyzing very thin films with much higher sensitivity than normal Fourier transform infrared ͑FTIR͒ analysis. A schematic plot of ATR measurement is shown in Fig. 1. The infrared radiation signal penetrated into the monolayer film only once during the measurement. Typical thickness for normal FTIR analysis is equal or larger than 1000 Å to get desirable signal noise ratio. However, the actually used films in electronic devices may not necessarily meet this thickness requirement. In this work, all the films' thicknesses are less than 20 nm. By using ATR and Woollam SE analysis we can directly study the optical properties of these ultrathin nitride films. Other films properties like electrical data were also discussed. ExperimentalSingle crystal ͑100͒ p-type silico...

Thin films of ZnS,-,O, and ZnS,-,Se, have been deposited on to p-Si by radio-frequency sputtering either a solid target of ZnS in Ar/02 mixtures or solid targets of ZnS and ZnSe. Both types of ternary compound are more conducting than pure ZnS, and t h u s potentially useful for DC electroluminescence. The ZnS,_,O,films prepared in 02/Ar mixtures greaterthan 2% 0, are too conducting for electroluminescent devices; gas mixtures containing only fractional percentages of O2 will yield appropriate conductivities. For ZnS,-,Se, films the ideal value of x lies between 0.01 and 0.05.

Advancing technology nodes in semiconductor manufacturing require more demanding lithographic performance for patterning. The advent of 45 nm development necessitated dual damascene lithography moving from a KrF-based bilayer approach to one that includes an ArF photoresist for higher resolution. There are multiple methods for an ArF dual damascene (via first, trench last) system, including bilayer, trilayer and hard mask approaches. Flash manufacturing demands are sensitive to process cost of ownership, so more complex approaches such as trilayer and hard mask film stacks were not as attractive. One method examined as an ArF dual damascene solution was a so-called "modified bilayer" approach, which is a combination of both KrF and ArF resist materials; in particular, this film stack allows for the use of ArF silicon-containing resists along with a variety of anti-reflective and gap fill underlayer materials. The modified bilayer approach afforded many advantages, including chemical compatibility, etch performance and process robustness. The modified bilayer approach represents a culmination of learning that has enabled 45 nm back end of the line (BEOL) dual damascene processing with ArF silicon-containing photoresists.

With the rapid advances of deep submicron semiconductor technology, identifying defects is converted into a challenge for different modules in the fabrication of chips. Yield engineers often do bilinap on a memory circuit array (SRAM) to identify the failure bits. This is followed by a wafer stripback to look for visual defects at each deprocessei layer for feedback to the Fab. However, to identify the root cause of a problem, Fab engineers must be able to detect similar defects either on the product wafers in process or some short ioop test wafers. In the photolithography process, we recognize that the detection of defects is becoming as important as satisfying the Critical dimension (CD) of the device. For a multi-level metallization chemically mechanical polish backend process, it is very difficult to detect missing contacts or via at the masking steps due to metal grain roughness, film color variation and/orprevious layer defects. Often, photolithography engineer must depend on Photo Cell Monitor (PCM) and short ioop experiments for controlling baseline defects and improvement.In this paper, we discuss the fmdings on the Poly mask PCM and the Contact mask PCM. We present the comparison betweenthe Poly mask and the Contact mask ofthe I-line Phase Shifted Via mask and DUV maskprocess for a O.l8micron process technology. The correlation and the different type ofdefects between the Contact PCM and the Poly Mask are discussed. The Contact PCM was found to be more sensitive and correlated to contact failure at sort yield better. We also dedicate to study the root cause of a single closed contact hole in the Contact mask short loop experiment for a 0. 18 micron process technology. A single closed contact defect was often caused by the developer process, such as bubbles in the line, resist residue left behind, and the rinse mechanism. We also found surfactant solution helps to improve the surface tension of the wafer for the developer process and this prevents Ieliminates a single dosed contact hole defects. The applications and effects of using different subsirates like SiON, different thickness ofOxides, and Poly in the Contact Photo Mask is shown. Finally, some defect troubleshooting techniques and the root cause analysis are also discussed.