US 7,024,066 B1 · Littrow gratings as alignment structures for the wafer level testing of optical and optoelectronic chips

Abstract

This application describes, among others, wafer designs, testing systems and techniques for wafer-level optical and optoelectronic testing by coupling probe light to/from the top of the wafer. In the described exemplary implementations, wafers are designed with one or more optical alignment features or structures. The alignment structures are alongside the devices to be tested, but are easier to find or locate by optical means, than the devices to be tested. An optical diffraction grating structure such as a Littrow grating may be used as reflective alignment structures. (FIG. 6B and paragraph 56.) A Littrow grating as an alignment structure produces a retro-reflection. A Littrow grating is a one-port optical device, with input and output beams going along the same path. Various exemplary implementations are shown in FIGS. 3C, 5, 6A, 6B, 7A and 7B and described in paragraphs 18–21, 39–40 and 53–64.

Claims22

Dependent claims

An apparatus comprising:

an integrated substrate,
an optical probe with an optical port above the substrate,
a Littrow grating disposed on the integrated substrate, and
a plurality of optical structures disposed on the substrate,
where a light beam is directed down from the optical port of the optical probe to the Littrow grating,
the light beam is retro-reflected up by the Littrow grating to the optical port of the optical probe, and
there is a plurality of positional relationships comprised of a positional relationship between the Littrow grating and each of the plurality of optical structures.

4 more elements

Dependencies are inferred from the claim text.

Littrow gratings as alignment structures for the wafer level testing of optical and optoelectronic chips

Life of this patent

Littrow gratings as alignment structures for the wafer level testing of optical and optoelectronic chips

Life of this patent

Abstract

Claims22