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Auger electron spectroscopy analyses of submicron features on semiconductor surfaces are routinely accompanied by analytical artifacts such as sample degradation and background contributions arising from electron beam scattering. Submicron analyses are commonly carried out at electron beam densities in excess of 1 A cm -2 and are especially damaging to silicon oxides. The evolution of oxide reduction is observed both as a loss of oxygen versus beam exposure and in a complementary growth of Si LVV and Si KLL elemental peaks. The O KLL signal intensity from a 1 μm 2 area of thermally grown oxide is found to decrease by 22% after exposure to a rastered 20 kV/10 nA beam for 10 min. Another aspect of submicron analysis is the contribution to survey spectra that originates when surrounding material is excited by backscattered electrons. Background contributions may dominate AES spectra even when the sample is flat and the probing beam is smaller than the feature of interest. Tungsten damascene contacts provide a useful platform for investigating this phenomenon in the absence of topography. Spectra have been collected from tungsten contacts of various sizes and the target and background contributions quantified. When a 0.25 μm diameter tungsten contact is probed with a narrow 20 kV beam, the W MNN signal intensity is determined to be only 70% of that emitted from a large tungsten structure. Target signal reduction coincides with increased signal contributions from the surrounding oxide.

As lithographic technology nodes advance beyond the 193 nm generation, the optical absorption of organic materials will require the use of thin layer imaging (TLI) techniques. Of the techniques under consideration, the use of ultra-thin resist (UTR) over a hardmask is the most desirable because of its simplicity and close similarity to standard single layer resist processes. Prior work has demonstrated that the UTR process is capable of pattern transfer to poly silicon device layers with as little as 1000 Angstrom of resist on flat wafers using 248 nm lithography. This was achieved with defect levels comparable to a conventional 5000 Angstrom resist process. In this work, we demonstrate 'proof of concept' by integrating the UTR process into the transistor gate module of a production device using 248 nm lithography. In doing so we focus on three key areas for manufacturability: inherent defectivity of UTR films, sensitivity of thin resist to topography, and quality of pattern transfer. We find that pinhole defects are of little concern in the UTR process after SEM review of defects on un-patterned UTR films. We show that the UTR process is sensitive to wafer topography, since it does not provide a completely planar surface over the underlying device features. Finally, we demonstrate that the UTR process is capable of reliable pattern transfer on a production device with defect levels comparable to the thicker baseline single layer resist process.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The thermodynamic properties of the binary LiZn, LiCd and LiPb alloy systems were investigated in an organic solvent-based electrolyte at ambient temperature. Titration curves showed several intermediate phases existing in each lithium alloy system. There was a wide composition range in Li y Cd (1.5 ⩽ y ⩽ 3), which showed a very low equilibrium potential (below 60 mV) against pure lithium. There was a longer potential plateau in the LiPb system corresponding to Li y Pb (1 ⩽ y ⩽ 3) at about 450 mV against pure lithium. The preliminary charge-discharge and polarization results showed rather fast kinetics for Li y Zn (0.67 ⩽ y ⩽ 1), Li y Cd (1.5 y y Pb (1 y

Boron nitride membranes (produced through chemical vapor deposition of diborane and ammonia) have been exposed to synchrotron radiation and have showed severe degradation in optical properties after absorbing doses on the order of 200kJ/cm3. Damage kinetics are described as well as measurements made to identify the damage mechanism. Preliminary results on associated mechanical damage are also presented. Boron nitride membranes (produced through the pyrolysis of borazine), silicon nitride and silicon membranes exposed and tested in the same manner showed no such degradation.

New Energy- Dependent Soft X -Ray Damage in MOS DevicesTung -Yi Chan, Henry Gaw, Daniel SeligsonIntel Corporation, SC2 -253065 Bowers AvenueSanta Clara, CA 95051Lawrence Pan, Paul L. King, and Piero PianettaStanford Synchrotron Radiation LaboratorySLAC /SSRL Bin 69, P.O. Box 4349Stanford, CA 94305AbstractAn energy- dependent soft x- ray- induced device damage has been discovered in MOSdevices fabricated using standard CMOS process. MOS devices were irradiated bymonochromatic x -rays in energy range just above and below the silicon K -edge (1.84keV). Photons below the K -edge is found to create more damage in the oxide andoxide /silicon interface than photons above the K -edge. This energy- dependent damageeffect is believed to be due to charge traps generated during device fabrication. Itis found that data for both n- and p -type devices lie along a universal curve ifnormalized threshold voltage shifts are plotted against absorbed dose in the oxide.The threshold voltage shift saturates when the absorbed dose in the oxide exceeds1.4X105 mJ /cm3, corresponding to 6 Mrad in the oxide.Using isochronal anneals, the trapped charge damage is found to recover with anactivation energy of 0.38 eV. A discrete radiation - induced damage state appears inthe low frequency C -V curve in a temperature range from 175 0C to 325 °C.I. IntroductionX -ray lithography is likely to displace optical lithography for semiconductordevice fabrication with dimensions < 0.4 um. Since x -ray photons have energies muchhigher than the band gap of silicon dioxide (about 9 eV), oxide damage caused by x-ray irradiation may be a serious concern in the application of x -ray lithography. Theeffects of x -rays and other forms of ionizing radiation on MOS structures have beenextensively studied for years [1 -4]. However, little work has been done to examinethe effect of varying the incident x -ray energy [5].In this paper, synchrotron x -ray sources were used to study the effect of x-rayenergy on radiation - induced device damage. X -ray photons studied have energy justabove and just below the silicon K -edge (1.84 keV). An energy- dependent soft