Deposition of debris produced in laser ablation of a workpiece situated in a vacuum chamber is reduced by introduction a background gas into the vacuum chamber prior to or during laser ablation. The background gas can be introduced diffusely into the vacuum chamber and can reduce contamination of surfaces such as a surface of an optical window that faces the workpiece during processing. Directed introduction of a background gas can be used as well and in some cases the same or a different background gas is directed to a workpiece surface at the same or different pressure than that associated with diffuse introduction of the background gas to reduce contamination of the workpiece surface with laser ablation debris.

Deposition of debris produced in laser ablation of a workpiece situated in a vacuum chamber is reduced by introduction a background gas into the vacuum chamber prior to or during laser ablation. The background gas can be introduced diffusely into the vacuum chamber and can reduce contamination of surfaces such as a surface of an optical window that faces the workpiece during processing. Directed introduction of a background gas can be used as well and in some cases the same or a different background gas is directed to a workpiece surface at the same or different pressure than that associated with diffuse introduction of the background gas to reduce contamination of the workpiece surface with laser ablation debris.

A nanopore structure includes an aperture extending from a first surface to a second surface of a substrate, the aperture having a wall comprising gold ions embedded in the substrate, the wall defining a first diameter; a first deoxyribonucleic acid (DNA) layer including a thiolated DNA strand covalently bonded to the embedded gold ions within the wall of the aperture; and a second DNA layer hydrogen bonded to the first DNA layer, the second DNA layer defines a substantially cylindrical nanopore that defines a second diameter within the wall of the aperture, the second DNA layer including a single-stranded DNA strand; wherein the second diameter is less than the first diameter.

A nanopore structure includes an aperture extending from a first surface to a second surface of a substrate, the aperture having a wall comprising gold ions embedded in the substrate, the wall defining a first diameter; a first deoxyribonucleic acid (DNA) layer including a thiolated DNA strand covalently bonded to the embedded gold ions within the wall of the aperture; and a second DNA layer hydrogen bonded to the first DNA layer, the second DNA layer defines a substantially cylindrical nanopore that defines a second diameter within the wall of the aperture, the second DNA layer including a single-stranded DNA strand; wherein the second diameter is less than the first diameter.

A substrate bonder includes a gas discharge hole (1413c, 1423c) provided in a second region in a stage and a head, and a controller that controls a chuck drive unit and a gas supply unit (1492) to release holding of a substrate with an electrostatic chuck (1413, 1423) and discharge gas from the gas discharge hole (1413c, 1423c) in a state where a peripheral portion of the substrate is held by the electrostatic chuck before bringing central portions of the substrates into contact with each other. The stage and the head include grooves (1413d, 1423d) provided in the second region and communicating with the gas discharge holes (1413c, 1423c).

A substrate bonder includes a gas discharge hole (1413c, 1423c) provided in a second region in a stage and a head, and a controller that controls a chuck drive unit and a gas supply unit (1492) to release holding of a substrate with an electrostatic chuck (1413, 1423) and discharge gas from the gas discharge hole (1413c, 1423c) in a state where a peripheral portion of the substrate is held by the electrostatic chuck before bringing central portions of the substrates into contact with each other. The stage and the head include grooves (1413d, 1423d) provided in the second region and communicating with the gas discharge holes (1413c, 1423c).