A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

A wafer polishing apparatus includes a wafer polishing assembly having a plurality of wafer carriers for substantially simultaneously polishing a plurality of wafers against a rotating polishing surface. A plurality of wafers to be polished are substantially simultaneously loaded into the plurality of wafer carriers by wafer holding apparatus of an index table. Similarly, a plurality of wafer carriers are substantially simultaneously unloaded into wafer holding apparatus of the index table. The wafer carriers are individually computer controlled for exact polishing and different polishing requirements can be met at the same time by different wafer carriers.

Wafer polishing method and apparatus

A polishing head for polishing a semiconductor wafer is described. The head design enables a wafer retainer to float during polishing and yet extend beyond a wafer carrier to define a pocket for the wafer and thereby facilitate wafer changing. The head construction also enables the carrier to be selectively projected beyond the retainer so that the surface of the carrier is easily accessible for changing an insert or the like. The head uses a positive air pressure to press the wafer against the polishing pad and the head includes interfering mechanical constructions which provide the positions mentioned above.

Wafer polisher head having floating retainer ring

A wafer polishing head utilizes a wafer backing member having a wafer facing pocket which is sealed against the wafer and is pressurized with air or other fluid to provide a uniform force distribution pattern across the width of the wafer inside an edge seal feature at the perimeter of the wafer to urge (or press) the wafer uniformly toward a polishing pad. Wafer polishing is carried out uniformly without variations in the amount of wafer material across the usable area of the wafer. A frictional force between the seal feature of the backing member and the surface of the wafer transfers rotational movement of the head to the wafer during polishing. A pressure controlled bellows supports and presses the wafer backing member toward the polishing pad and accommodates any dimensional variation between the polishing head and the polishing pad as the polishing head is moved relative to the polishing pad. An integral, but independently retractable and extendable retaining ring assembly is provided around the wafer backing member and wafer to uniformly and independently control the pressure of a wafer perimeter retaining ring on the polishing ad of a wafer polishing bed.

Fluid pressure regulated wafer polishing head

A chemical mechanical polishing apparatus polishes the surface of a substrate to remove material therefrom The apparatus includes a carrier, which positions the substrate against the rotating polishing pad The carrier includes an integral loading member therein, which controls the load force of the substrate against the polishing pad Multiple substrates may be simultaneously polished on a single rotating polishing pad, and the polishing pad may be rotationally oscillated to reduce the likelihood that any contaminants are transferred from one substrate to another along the polishing pad A multi-lobed groove in the polishing pad may be used, in conjunction with a moving substrate, to polish the surface of the substrate

Chemical mechanical polishing apparatus with improved polishing control

A polishing apparatus has a conventional carrier with a plurality of floating subcarriers. The benefits of single wafer polishing are achieved with the economies of multiple wafer polishing by adding the plurality of floating subcarriers to the conventional carrier. Each subcarrier has a single wafer adhered to its underside. Axial freedom is provided to duplicate the dynamics of single wafer polishing. The required axial freedom is obtained by axially loading each subcarrier via a mechanical spring or via pneumatic/hydraulic devices. In two variations, each subcarrier is also allowed auto-rotational freedom. In another two variations, the subcarriers are rotationally driven. In all variations, the wafers adhered to the floating subcarriers are substantially uniformly polished and the total indicated reading of the maximum deviation on the wafer surface is improved.

Kenneth C. Struven

Papers

Floating subcarriers for wafer polishing apparatus