Wafers where deposited with BPSG films having phosphorus concentration varying from 3.65 to 6.25% and boron concentration varying from 4 to 5.7%. These wafers were polished using CMP and the rates were found to depend on dopant concentrations. A fit to the data indicated that removal rates were more than 3 times as sensitive to boron concentration compared to phosphorus concentration. For a constant phosphorus concentration of 5%, each percent increase in boron increases CMP removal rate by 340 Å/min. For a constant boron concentration of 5%, each percent increase in phosphorus increases CMP removal rate by 96 Å/min.

A new set of wafer-scale patterns has been designed for analysis and modeling of key CMP effects. In particular, the goal of this work is to develop methods to characterize the planarization capability of a CMP process using simple measurements on wafer scale patterns. We examine means to pattern large trenches (e.g. 1 to 15 mm wide and 15 mm tall) or circles across 4” and 8” wafers, and present oxide polish results using both stacked and solo pads in conventional polish processes. We find that large separation (15 mm) between trenches enables cleaner measurement and analysis. Examination of oxide removal in the center of the trench as a function of trench width shows a saturation at a length comparable to the planarization length extracted from earlier studies of small-scale oxide patterns. Increase in polish pressure is observed to decrease this saturation point. Such wafer scale patterns may provide information on pad flexing limits in addition to planarization length, and promise to be useful in both patterned wafer CMP modeling and studies of wafer scale CMP dependencies such as nanotopography.

This paper reports a technological advancement in developing and implementing a novel retaining ring of advanced edge performance (AEPTM ring) for an advanced polishing head design. The AEP ring has been successfully used for significantly improved CMP performance in different CMP applications: oxide (PMD and ILD), shallow trench isolation (STI), polysilicon, metal (W and Cu), silicon-on-insulator (SOI), and silicon CMP. Robust processes have been developed using AEP ring along with many hardware upgrades for each application with extended runs to meet requirements of advanced IC device fabrication.

Measurements of the decomposition of mixtures of boron trichloride (BCl3), titanium tetrachloride (TiCl4), and hydrogen at elevated temperatures are presented. The decomposition of BCl3 with hydrogen appears to drive the chemistry in this system. The species depositing boron on the surface contains at least 2 chlorine atoms. Once deposited, the surface chlorine is removed by reaction with hydrogen to form HCl and, presumably, surface B-H bonds.

The kinetics of gas-phase reactions occurring during the CVD of boron nitride (BN) from BCl3 and NH3 are investigated using an elementary reaction mechanism whose rate constants were obtained from theoretical predictions and literature sources. Plug-flow calculations using this mechanism predict that unimolecular decomposition of BCl3 is not significant under typical CVD conditions, but that some NH3 decomposition may occur, especially for deposition occurring at atmospheric pressure. Reaction of BCl3 with NH3 is rapid under CVD conditions and yields species containing both boron and nitrogen. One of these compounds, Cl2BNH2, is predicted to be a key gas-phase precursor to BN.

Methyltrichlorosilane (MTS) is a precursor commonly used in the production of silicon carbide for composites, protective coatings, and structural ceramics. Experiments suggest that MTS decomposes in the gas phase to produce a large number of species whose surface reactivity is expected to vary widely. In this work, we discuss the development of a gas-phase mechanism that describes the decomposition of MTS. Rate coefficients for the reactions were obtained from literature sources, theoretical methods, and comparisons with analogous reaction chemistry. Several unknown reaction rates were fit to experimental measurements of MTS decomposition. The results are used to predict the major reaction paths, identify reactions to which product concentrations are sensitive, and determine the rate-limiting step for MTS decomposition.

Experimental measurements of the decomposition of methyltrichlorosilane (MTS), a common silicon carbide precursor, in a high-temperature flow reactor are presented. Methane, hydrogen chloride, and silicon tetrachloride are observed as products of the decomposition. Trapping experiments with acetylene and ethylene also detected SiCl3 as a decomposition product. Upper limits on the concentrations of any CH3Cl, HSiCl3, H2SiCl2, or H2C=SiCl2 which might form are provided. Quantitative measurements of product branching and MTS decomposition rates are presented. The results suggest a radical-chain mechanism for the decomposition in hydrogen but not in helium.

Experimental measurements of the decomposition of methyltrichlorosilane (MTS), a common silicon carbide precursor, in a high-temperature flow reactor are presented. The results indicate that methane and hydrogen chloride are major products of the decomposition. No chlorinated silane products were observed. Hydrogen carrier gas was found to increase the rate of MTS decomposition. The observations suggest a radical-chain mechanism for the decomposition. The implications for silicon carbide chemical vapor deposition are discussed.