Abstract: A method of: directing an exposing light through an optical diffuser; directing the diffused light though a photomask having transparent areas corresponding to a gray-tone pattern; directing the masked light onto a photoresist material on a substrate; developing the photoresist to produce a three dimensional structure in the photoresist.

Abstract: The device etches semiconductors with a large surface area in a trough-shaped receptacle containing a liquid electrolyte. A sample head is mounted inside the etching trough, and is provided with a device for holding at least one semiconductor wafer. The device is tilted to promote turbulent electrolyte flow in a space between a bottom surface of the semiconductor wafer and top surface of the trough-shaped receptacle.

Abstract: A biological sensor which includes: a macroporous semiconductor structure comprising a central layer interposed between upper and lower layers, each of the upper and lower layers including strata of alternating porosity; and one or more probes coupled to the porous semiconductor structure, the one or more probes binding to a target molecule, whereby a detectable change occurs in a refractive index of the biological sensor upon binding of the one or more probes to the target molecule. Methods of making the biological sensor and methods of using the same are disclosed, as is a detection device which includes such a biological sensor.

Abstract: Mesoporous silicon optical filters can be used to filter light in the near infrared, mid infrared and/or far infrared spectral ranges. The special advantages of mesoporous filters in cold temperature applications include improved mechanical stability, absence of delamination problems, manufacturability, and transparency of the mesoporous silicon material throughout a wide spectral range. Techniques are disclosed for enhancing the transparency range and environmental and mechanical stabilities of the mesoporous silicon filters.

Abstract: The device etches semiconductors with a large surface area in a trough-shaped receptacle containing a liquid electrolyte. A sample head is mounted inside the etching trough, and is provided with a device for holding at least one semiconductor wafer. The device is tilted to promote turbulent electrolyte flow in a space between a bottom surface of the semiconductor wafer and top surface of the trough-shaped receptacle.

Abstract: Methods and apparatus for providing closed-loop control over an electrochemical etching process during porous semiconductor fabrication enhance the quality of the porous semiconductor materials, especially those contained structural variations (such as porosity or morphology variations) along the thickness of said porous semiconductors. Such enhancement of the control over the electrochemical etching process is highly desired for many applications of porous semiconductor materials.