Ultrathin 2.5 nm high-k aluminum oxide ͑Al 2 O 3 ͒ films on p-type silicon ͑001͒ deposited by atomic layer deposition ͑ALD͒ were investigated with noncontact atomic force microscopy ͑NC-AFM͒ in ultrahigh vacuum, using a conductive tip. Constant force gradient images revealed the presence of oxide charges and experimental observations at different tip-sample potentials were compared with calculations of the electric force gradient based on a spherical tip model. This model could be substantially improved by the incorporation of the image of the tip in the semiconductor substrate. Based on the signals of different oxide charges observed, a homogenous depth distribution of those charges was derived. Application of a potential difference between sample and tip was found to result in a net electric force depending on the contact potential difference ͑CPD͒ and effective tip-sample capacitance, which depends on the depletion or accumulation layer that is induced by the bias voltage. CPD images could be constructed from height-voltage spectra with active feedback. Apart from oxide charges large-scale ͑150-300 nm lateral size͒ and small-scale ͑50-100 nm͒ CPD fluctuations were observed, the latter showing a high degree of correlation with topography features. This correlation might be a result from the surface-inhibited growth mode of the investigated layers.

Recent efforts on growth modeling of atomic layer deposition (ALD) have emphasized the need for an accurate understanding of the process, especially of the initial stage of the deposition. In this paper the first results obtained from in situ reflective high-energy electron diffraction (RHEED) measurements during the ALD of Al 2 O 3 on Si(001), using Al(CH 3 ) 3 and H 2 O as precursors, are presented. The goal of this work is to show the feasibility of using a surface-sensitive analysis technique to study the surface chemistry during ALD. The results show the expected decrease in reflected intensity on deposition of aluminum atoms and a recovery of intensity, attributed to removal of methyl groups from the surface, on exposure to H 2 O. Growth initiation by TMA exposure, and subsequent growth inhibition are observed. A discrete time model of ALD is used to analyze the measured decay in reflected intensity.

We investigated the thickness evolution of silicon dioxide grown on a silicon surface terminated by H-Si groups, at room temperature and an elevated temperature of 250 o C. At room temperature, we observed a noticeable difference in the oxidation rate between light-illuminated samples and the samples kept in the dark. No measurable difference between the oxidation of p-type Si and n-type Si was observed. To describe the low-temperature oxidation, we made further steps towards the extension of our oxidation model earlier developed for thin oxides grown in the temperature range 750-950 o C.

This article describes a novel CVD process for Titanium Nitride (TiN) films developed in a 300 mm vertical furnace. We have solved Chlorine incorporation at low temperature inside the TiN layer while at the same time the batch process yields a 3 times higher throughput per dual reactor system compared to a single wafer system with 3 chambers. We show process results for load sizes ranging from 5 to as much as 100 wafers that prove filler wafers are only required to a minimum. Applications with the developed TiN process are in Metal-Insulator-Metal memory devices such as Stack DRAM, and embedded DRAM.

Gate leakage has complicated the layout and measurement of C-V test structures. In this paper the impact of metal gate introduction to C-V test structure design is discussed. The metal gate allows for widergate structures and for the application of n + -p + diffusion edges. We show, both theoretically and with experimental data, the impact of both design modifications on C-V measurement results.