For the Ge nanowire formation in a gate-all-around (GAA) integration scheme, a selective etch of Si0.5Ge0.5 or Si0.3Ge0.7 selective to Ge is considered. Two wet process approaches were evaluated: a boiling TMAH as a commodity chemistry is compared with a formulated chemistry using a multi-stack SiGe/Ge layer as a test vehicle. The boiling TMAH exhibits an anisotropic etch of the SiGe whereas the formulated semi-aqueous chemistry removes the sacrificial SiGe by an isotropic etch which makes the process suitable for a Ge nanowire release process.

L'invention se rapporte a des compositions et a des procedes d'elimination de maniere pratique et efficace d'un materiau de NiPt (1 a 25 %) sur des dispositifs microelectroniques presentant le meme sur ceux-ci. Les compositions sont pratiquement compatibles avec d'autres materiaux presents sur le dispositif microelectronique tels que des materiaux de grilles metalliques.

At present there is a well recognized need for increased capacitance areal density in advanced DRAMs, i.e., for 256 Mb and future generations. Conventional silicon oxide and nitride dielectrics are the standard, and DRAM manufacturers are faced with greater and greater cell complexity in order to realize adequate capacitance. An alternative solution is to use more complicated dielectrics with higher relative permittivity (e) enabling simplified capacitor geometry and associated fabrication processes. The predominant choice for the high e dielectric has been (Ba,Sr)TiO3 @ST) based on its dielectric properties, low leakage, and chemical stability.

One approach for the deposition of porous PECVD CDO films uses simultaneous deposition of a backbone material and a sacrificial material (porogen) followed by post deposition processing to remove the porogen and harden the film. For ULK (k<2.2) films the pore volume fraction is typically 40% or higher. Efficient incorporation and removal of the porogen becomes increasingly important as lower k values dictate higher pore volume fractions. We will describe efforts to identify optimal hydrocarbon based porogen precursors with a view toward efficient incorporation and removal. A large number of suitable porogen precursors were investigated and we found that relatively small changes in the chemical structure of the porogen can result in large changes in incorporation and removal efficiencies. In many cases significant amounts of graphitic carbon residue can be left behind when these porogens are removed via UV assisted thermal removal. These residues can result in degraded dielectric properties such as increased dielectric loss factors, making complete removal essential. Additional screening was performed using porogen precursors alone. Bicyclic precursors were found to have the highest incorporation and removal efficiencies. For the two most promising porogen precursors, norbornadiene and norbornene, we have optimized the deposition and cure processes using DEOMORS as the backbone precursor. For films deposited with DEOMORS as the backbone and norbornene as the porogen we observed a k value of 2.17 with a hardness of 0.6GPa, modulus of 6.5GPa and average pore radius of 1nm.

Structural properties of polycrystalline Pb(Zr0.35Ti0.65)O3(PZT) thin films grown by metalorganic chemical vapor deposition on Ir bottom electrodes were investigated. Symmetric x-ray diffraction measurements showed that as-deposited 1500 íthick PZT films are partially tetragonal and partially rhombohedral. Cross-section scanning electron microscopy showed that these films have a polycrystalline columnar microstructure with grains extending through the thickness of the film. X-ray depth profiling using the grazing-incidence asymmetric Bragg scattering geometry suggests that each grain has a bilayer structure consisting of a near-surface region in the etragonal phase and the region at the bottom electrode interface in the rhombohedral hase. The required compatibility between the tetragonal and rhombohedral phases in he proposed layered structure of the 1500 Å PZT can explain the peak shifts observed n the symmetric x-ray diffraction results of thicker PZT films.