Photoemission studies of quantum well states in thin films

A DC magnetron sputter reactor for sputtering deposition materials such as tantalum and tantalum nitride, for example, and its method of use, in which self-ionized plasma (SIP) sputtering and capacitively coupled plasma (CCP) sputtering are promoted, either together or alternately, in the same chamber. Also, bottom coverage may be thinned or eliminated by inductively-coupled plasma (ICP) resputtering. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. CCP is provided by a pedestal electrode which capacitively couples RF energy into a plasma. The CCP plasma is preferably enhanced by a magnetic field generated by electromagnetic coils surrounding the pedestal which act to confine the CCP plasma and increase its density.

Self-ionized and capacitively-coupled plasma for sputtering and resputtering

Reactors for vapor deposition of materials onto a microelectronic workpiece, systems that include such reactors, and methods for depositing materials onto microelectronic workpieces. In one embodiment, a reactor for vapor deposition of a material comprises a reaction chamber and a gas distributor. The reaction chamber can include an inlet and an outlet. The gas distributor is positioned in the reaction chamber. The gas distributor has a compartment coupled to the inlet to receive a gas flow and a distributor plate including a first surface facing the compartment, a second surface facing the reaction chamber, and a plurality of passageways. The passageways extend through the distributor plate from the first surface to the second surface. Additionally, at least one of the passageways has at least a partially occluded flow path through the plate. For example, the occluded passageway can be canted at an oblique angle relative to the first surface of the distributor plate so that gas flowing through the canted passageway changes direction as it passes through the distributor plate.

Apparatus and method for depositing materials onto microelectronic workpieces

A method and apparatus for etching photomasks is provided herein. In one embodiment, the apparatus comprises a process chamber having a support pedestal adapted for receiving a photomask. An ion-neutral shield is disposed above the pedestal and a deflector plate assembly is provided above the ion-neutral shield. The deflector plate assembly defines a gas flow direction for process gases towards the ion-neutral shield, while the ion-neutral shield is used to establish a desired distribution of ion and neutral species in a plasma for etching the photomask.

Method and apparatus for photomask plasma etching

Angle-resolved photoemission from atomically uniform silver films on iron (100) shows quantum-well states for absolutely determined film thicknesses ranging from 1 to ∼100 monolayers. These states can be understood in terms of Fabry-Perot modes in an electron interferometer. A quantitative line shape analysis over the entire two orders of magnitude of thickness range yields an accurate measurement of the band structure, quasiparticle lifetime, electron reflectivity, and phase shift. Effects of confinement energy gap, reflection loss, and surface scattering caused by controlled roughness are demonstrated.

http://science.sciencemag.org/content/sci/283/5408/1709.full.pdf

Quantum-well states as fabry-Perot modes in a thin-film electron interferometer

Ag is grown epitaxially on Cu(111) to form quantum wells. The resulting quantum-well states and resonances, observed with angle-resolved photoemission, exhibit shifts in energy for varying emission directions and for changing Ag-film thicknesses. The results are utilized in a determination of the Ag bulk sp-band dispersion relation near the L point in the Brillouin zone. Effective masses and the Fermi surface near the L point are deduced. The Fermi surface agrees well with that obtained earlier from de Haas--van Alphen measurements.

Determination of the bulk band structure of Ag in Ag/Cu(111) quantum-well systems

A novel method of in-situ cleaning a Ti target in a Ti+TiN anti-reflective coating process when such Ti and TiN deposition process are conducted in the same process chamber by the addition of a simple process step and without the use of a shutter.

Method for in-situ cleaning a Ti target in a Ti + TiN coating process

The phase shift upon reflection of a valence Bloch electron in Ag at the Ag/Cu(111) interface is determined by angle-resolved photoemission. It shows a singularity at the band edge of Cu, allowing a determination of the substrate band-edge energy. The singular behavior is shown to be a characteristic interfacial property. A simple-model calculation reproduces the main features of the data.

Probing interfacial properties with Bloch electrons: Ag on Cu(111)

Article formed by in-situ cleaning a Ti target in a Ti+TiN coating process

A method of deposition for W or TiW on a silicon wafer in a physical vapor deposition chamber equipped with a clamping ring without incurring arcing problem between the wafer and the clamping ring by utilizing a novel two-step high-pressure/low-pressure process in which a first depositing step is carried out at a relatively high pressure above 11 mTorr so as to form an electrical bridge between the wafer and the clamping ring and a second depositing step is carried out at a lower pressure so as to form a high-quality conductive film.

Mark Mueller

Papers

Determination of the bulk band structure of Ag in Ag/Cu(111) quantum-well systems

Method for in-situ cleaning a Ti target in a Ti + TiN coating process

Probing interfacial properties with Bloch electrons: Ag on Cu(111)

Article formed by in-situ cleaning a Ti target in a Ti+TiN coating process

Two-step deposition process for preventing arcs