Browse Prior Art Database

Silicon Immersion/Heat-sink Lens

IP.com Disclosure Number: IPCOM000099373D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Heinrich, HK: AUTHOR

Abstract

Disclosed is a concept for an integral heat-sink/immersion lens, which will simultaneously provide cooling for high-power silicon integrated circuits and a high numerical aperture silicon immersion lens for enhancing the spatial resolution of backside optical probing systems (1,2).

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Silicon Immersion/Heat-sink Lens

       Disclosed is a concept for an integral heat-sink/immersion
lens, which will simultaneously provide cooling for high-power
silicon integrated circuits and a high numerical aperture silicon
immersion lens for enhancing the spatial resolution of backside
optical probing systems (1,2).

      Silicon is one of the few materials that possess both a high
thermal conductivity and excellent optical properties. Previously,
researchers have taken advantage of the thermal conduction properties
of silicon to fabricate heat-sink structures directly in silicon (3).
 For wavelengths greater that 1.3 mm silicon has low optical loss and
a very high index of refraction (n=3.5 at g = 1.3 mm).  Hence, a
silicon lens, placed in intimate contact with the substrate of an
integrated circuit, could form a very high numerical aperture (N A =
h sin r where r is the focus half-angle) objective, and thereby
substantially enhance the spatial resolution of an optical system.

      The immersion/heat-sink lens is fabricated by
thermoconductively bonding 1 a silicon hemisphere 2 to the walls of a
hole in the center of a silicon heat-sink 3.  A pair of top plates 4,
5 distributes the coolant from the entrance ports 6 into the
heat-sink and from the heat-sink to the output ports 7.

      Fluid flow 8 through the heat-sink channel 11 is designed such
that cylindrical symmetry around the optical axis is maintained to
minimize the optical effect of thermally induced index gradients
within the silicon hemisphere 2.  In add...