Near field optical scanning system employing microfabricated solid immersion lens

A near field optical scanning system for optically scanning an object comprising:

• a flexible silicon or silicon nitride cantilever arm having a free end and a fixed end,
• a solid immersion lens made of material having a high refractive index for focusing light onto an integral tip, said solid immersion lens and tip being formed integral with said flexible silicon or silicon nitride cantilever arm,
• a light source for projecting light into said solid immersion lens whereby it emerges from the end of the tip, focused by the solid immersion lens,
• means for holding the object opposite the tip within the near field of focused light emerging from the solid immersion lens, and
• a scanner for moving the object relative to the tip whereby the emerging light scans the object.

An optical scanning system for scanning an object comprising:

• a plurality of cantilevers formed in a wafer, each cantilever including:
• a flexible cantilever arm having a free end and a fixed end,
• an integral transparent tip comprising a sharp end and a solid immersion lens for focusing light into the sharp end of the tip, said tip carried at the free end of said cantilever arm with the sharp end extending perpendicular to the longitudinal axis of the cantilever arm,
• an aperture at the sharp end of the tip,
• a piezoelectric transducer means on said arm for positioning the free end of the arm to position the sharp end so that near field from the sharp end impinges on the object, and
• means for controllably applying light to said solid immersion lens.

A method of fabricating a solid immersion lens integrated with a cantilever, the method comprising the steps of:

• forming a cavity in a layer of silicon material,
• applying a layer of high refractive index material on the surface of said silicon layer to fill said cavity and form a layer on the surface of said first layer,
• forming a tip in said high refractive index material on a side opposite said hemispherical cavity, and
• etching away said first layer to release said high refractive index material to provide a cantilever with an integral solid immersion lens.

A method of fabricating a solid immersion lens integrated with a cantilever, the method comprising the steps of:

• forming a cavity in a substrate layer to define a solid immersion lens,
• filling said cavity and coating the surface of said substrate with a high refractive index material,
• planarizing said high refractive index material to remove a conformal depression,
• forming a tip in said high refractive index material on a side of said high refractive index material opposite said cavity,
• removing part of said coating of high refractive index material to define a cantilever, and
• etching said silicon substrate layer to release said cantilever and the solid immersion lens defined by said cavity.

The method of fabricating a solid immersion lens and tip integrated with a cantilever which comprises:

• forming a layer of high refractive index material,
• forming a lens shaped member of material which resists etching on the surface of said layer,
• etching the layer whereby to transfer the lens shape to the high refractive index material,
• forming a tip-shaped member of material which resists etching on the surface of the high refractive index material opposite the transferred lens shape etching the layer whereby to form at tip, and
• selectively etching the high refractive index material to define a cantilever with the lens at one end of the cantilever.