Abstract: A method of manufacturing a semiconductor structure comprising: depositing a first layer in contact with a first surface area of a substrate; depositing a second layer in contact with a second surface area of the substrate, the second surface area substantially co-planar with and outwards of the first surface area; depositing a third layer in contact with the first layer and the second layer; removing a portion of the third layer to expose a portion of the first layer; and removing at least a portion of the first layer to create a cavity between the substrate, the second layer and the third layer.

Abstract: An LED lighting unit comprising a support structure (14), an LED-based light emitting structure (10) mounted within the support structure and an optical beam shaping arrangement (50, 52) over the top of the support structure. The optical beam shaping arrangement comprises an optically transparent and thermally stable material, and the support structure supports the microstructured layer at a small height above the LED-based light emitting structure. This height may for example be less than 0.5 mm. The optical beam shaping arrangement enables a compact and low height lighting unit to be mounted on a carrier by reflow soldering without damaging the optical beam-shaping component.