Devices and methods for detecting orientation and shape of an object

A method of supporting and sensing a substrate for use in semiconductor processing, comprising:

• supporting a substrate over a first support structure, said structure comprising at least one fluid channel in communication with a gap between the first support structure and an underside of the supported substrate;
• flowing fluid through the fluid channel;
• measuring a property of the fluid beneath the supported substrate;
• and
• using the measured property to determine one or more of an orientation of the substrate with respect to the first support structure and a shape of the substrate.

A system for sensing a condition of a substrate over a support structure, the method comprising:

• a substrate holder having an upper surface extending beneath a substrate supported thereover, the upper surface including a recess configured to accommodate the substrate therein;
• at least one fluid injection channel which breaches the upper surface to inject fluid into a gap between the substrate and upper surface;
• a fluid pressure sensor configured to measure pressure beneath the substrate;
• and
• a controller connected to the pressure sensor and configured to read the pressure sensed by the pressure sensor;
• wherein the controller is configured to compare the sensed pressure to a plurality of empirically determined pressure ranges associated with a corresponding plurality of substrate conditions to thereby determine a condition of the substrate based upon the sensed pressure.

A substrate supporting and sensing apparatus, comprising

• a support structure for receiving and supporting a substantially horizontally oriented substrate;
• a substrate sensing structure provided with at least three gas channels, the gas channels configured to inject gas at spaced apart positions against a lower surface of a substrate supported on the support structure above the substrate sensing structure, each of the gas channels provided with a sensor configured to generate a sensor signal relating to a property of gas flow through the channel;
• and
• a controller connected to the sensors, the controller configured to read, for each of the sensors, the sensor signal, while the substrate is supported on the support structure, the controller producing from sensor readings an indication of an orientation of a substrate relative to the support structure.