Silicon oxide thin films have been deposited in plasma-assisted CVD process. With tetraethylorthosilcate (TEOS, Si(OC2H5)4) as precursor and an oxygen RF-plasma, thin films of 50–100nm were deposited on silicon wafers. The deposition process was controlled in situ by monitoring the soft X-ray reflectivity of the growing layer. The influence of additional gases such as nitrogen and changes of the plasma conditions on the resulting films have been studied by analyzing the films with grazing incidence X-ray reflectometry, infrared spectroscopy, spectral ellipsometry and capacitance–voltage and current–voltage measurements were performed at different temperatures.

Carbon films in a thickness range between 10 and 100nm were deposited on silicon and glass substrates in an RF-plasma CVD reactor using methane as precursor. Various deposition parameters were changed, such as methane gas flow, plasma power, temperature and bias voltage of the substrate, and different gases were added to the deposition process (nitrogen, hydrogen, krypton). During deposition, an in-situ soft X-ray reflectivity measurement provided information about the growing film and controlled the thickness of the film. The resulting carbon films were characterized by grazing incidence X-ray reflectometry, Auger electron spectroscopy, infrared spectroscopy and spectral ellipsometry. The results showed that the carbon films were polymeric, with a smooth surface. In addition, the photoluminescence of the films was measured. In addition, some of the films showed strong photoluminescence.

Molybdenum oxide thin films were prepared by plasma-enhanced chemical vapor deposition of molybdenum pentacarbonyl 1-methylbutylisonitrile. This precursor is an interesting alternative for the commonly used molybdenum hexacarbonyl, because the substance is liquid at room temperature, offers sufficient volatility and stability to air and water. The film growth was monitored in situ by a soft X-ray reflectivity measurement. The films were deposited with different plasma gases (hydrogen and oxygen) under different conditions and analysed by Auger electron spectroscopy, X-ray diffraction and spectral ellipsometry.

We present a method of deriving single layer thickness fluctuations of Mo/Si EUV multilayers from cross-sectional high-resolution transmission electron microscopy micrographs. The obtained thickness values for each layer are used in a layer model to calculate the grazing-incidence X-ray reflectivity (GIXRR) and the corresponding at-wavelength-reflectivity curves. Comparison with XRR measurements shows the strong effect of thickness fluctuations on the intensity of the secondary Kiessig fringes and the main Bragg maxima. This model results in substantially better reflectivity simulations than the standard periodic four-layer model or the assumption of statistically distributed (random) thickness errors. Results for reflectivity curves at 13-nm wavelength are discussed in terms of peak reflectivity, peak shift and further changes in the shape of the reflectivity curve.

Three periodic Mo/Si multilayers were prepared by electron-beam evaporation at different conditions. An in situ polishing of amorphous Si layers with Ar+ ions of 800eV energy and substrate heating to 170°C were used for the two of them which were designed as multilayer mirrors optimized for 13nm wavelength at normal incidence (30 periods of nominally 6.9nm). A third multilayer was deposited at room temperature with reduced Mo layer thicknesses and number of periods to suppress interface roughness buildup. The goal was a comparison of ion beam polishing and substrate heating in terms of the interface quality and evaluation of the merit of more sophisticated depositions. The interfaces were studied by specular X-ray reflectivity and interface diffuse scattering measured at Cu Kα1 wavelength. The interface morphology parameters are very close on ion beam polishing and substrate heating indicating a similar relaxation mechanism of the growing surface. The main difference is a larger thickness of the Mo5Si3 interlayers with substrate heating, which has practical implications for peak reflectivities. On the other hand, a slightly worse interface replication here is appealing for the applications where a good imaging contrast is of primary importance. At room temperature deposition, the interface roughness is nearly doubled at 3 times smaller number of multilayer periods.

We have studied the suitability of Plasma Enhanced Chemical Vapor Deposition (PECVD) to produce ultrasmooth silicon oxide layers ranging in thickness from some nanometers to some 10 nm. A tight process control of the layer thickness, layer density and microroughness of the growing film is required. We deposited silicon oxide on silicon wafers, float glass and superpolished quartz substrates. In a remote plasma enhanced CVD process, we used tetraethylorthosilicate (TEOS, Si(OC 2 H 5 ) 4 ) as precursor. Films with a thickness of some 10 nm were produced at different deposition parameters and characterized by in-situ soft X-ray reflectivity, hard X-ray diffraction and auger electron spectroscopy. Best results could be found for the deposition using TEOS in oxygen plasma. In case of SiO 2 layers deposited on standard glass substrates signifcant roughness smoothing was obtained.

Our aim was to produce EUV multilayer mirrors with a small spectral bandwidth ΔE≤3 eV at 70 eV peak energy using UHV electron beam evaporation by varying the thickness ratio (Γ=\(\)) between the absorber layer and the bilayer. The deposition process was controlled by in situ soft X-ray reflectometry, and ion-beam polishing as well as substrate-heating methods were applied to reduce the interface roughness. The reflection properties of the Mo–Si multilayer mirrors prepared were characterized by hard and soft X-ray reflectometry and details of the multilayer structure were revealed from cross-sectional transmission electron microscopy.

Molybdenum oxide/silicon oxide and tungsten oxide/silicon oxide multilayer with 24 periods and a period thickness of 9.2 nm were fabricated with plasma-enhanced MOCVD. The layer thickness was controlled by an in situ soft X-ray reflectivity measurement. For the deposition of the SiO2 layers, a new silicon organic precursor, pentamethylcyclopentadienyldisilane (Me5C5Si2H5) was used in an O2 remote plasma process. The high quality of multilayer interfaces was observed by cross-section transmission electron microscopy (TEM), the interface Toughness wasmeasured by hard X-ray reflectivity and diffuse scattering at grazing incidence experiments to be about 0.1 nm. Auger electron spectroscopy (AES) gives the information, that the silicon oxide is practically carbon free, and the carbon content of the metal oxides is low (<5%).

The e-beam deposited multilayers (MLS) were studied under rapid thermal annealing (RTA) between 250°C and 1000°C during 30 s. MLS with five Co/Si/W/Si periods, each 13.9 nm (MLS1) and 18 nm (MLS2) were deposited onto oxidized Si substrates. Samples were analyzed by X-ray diffraction, hard and soft X-ray reflectivity measurements and grazing incidence X-ray diffuse scattering. The MLS period, interface roughness and its lateral and vertical correlations were obtained by simulation of the hard X-ray reflectivity and diffuse scattering spectra. The MLS1 with thinner Co layers is more temperature resistant. However, its soft X-ray reflectivity is smaller. The results show that this is because of shorter lateral and vertical correlation lengths of the interface roughness which may considerably influence the X-ray reflectivity of multilayers.