Abstract: A method is for plasma etching elongate features in a generally planar workpiece of a type located in a chamber. The method includes etching a test workpiece in a flat configuration in the chamber, determining the respective angle of a longitudinal portion of the features relative to an axis passing orthogonally through the workpiece, and determining the curvature of the workpiece, which would have been required to reduce the angles, at least over a central portion of the workpiece, substantially to 0°. The method further includes processing a further workpiece of the same type whilst it is curved with the determined curvature.

Abstract: This invention relates to electrostatic clamping and associated clamps. A particular method is described of clamping a wafer, during the process that creates asymmetric stress in the wafer, to an electrostatic chuck having a concave portion in its clamping surface characterized in that the wafer is initially clamped around its periphery in a generally flat orientation and then is bowed into the concavity as the asymmetric stress is created in the wafer. It is particularly preferred that the degree of concavity of the chuck is such as to maintain a gas seal between the wafer and the chuck sufficient to allow backside cooling of the water.

Abstract: This invention relates to a method of etching a substrate in a chamber on an electrostatic chuck, which defines a gas cooling path at the substrate/chuck interface. The method includes electrostatically clamping the substrate on the chuck with gas in the gas path being at a first pressure; etching the substrate at a first power; detecting the end point for the etc; reducing the gas pressure to a second pressure at which the substrate floats on a gas; and over etching the wafer at a second power, which is lower than the first power.

Abstract: This invention relates to electrostatic clamping and associated clamps. A particular method is described of clamping a wafer, during the process that creates asymmetric stress in the wafer, to an electrostatic chuck having a concave portion in its clamping surface characterised in that the wafer is initially clamped around its periphery in a generally flat orientation and then is bowed into the concavity as the asymmetric stress is created in the wafer. It is particularly preferred that the degree of concavity of the chuck is such as to maintain a gas seal between the wafer and the chuck sufficient to allow backside cooling of the water.

Abstract: This invention relates to a method of etching a substrate in a chamber on an electrostatic chuck, which defines a gas cooling path at the substrate/chuck interface. The method includes electrostatically clamping the substrate on the chuck with gas in the gas path being at a first pressure; etching the substrate at a first power; detecting the end point for the etc; reducing the gas pressure to a second pressure at which the substrate floats on a gas; and over etching the wafer at a second power, which is lower than the first power.

Abstract: An electrostatic chuck 12 for a plasma reactor apparatus 10 comprises a base metallic section 23, a pair of electrodes 24 set in bonding material 27 and electrically insulated from the base by a plate 29 and a thick dielectric layer 20 (e.g. 0.5 to 1.5 mm), which covers the electrodes 24 and bonding material 27 and forms the support surfaces for wafers 31.