Patent ID: 6432695
Filing Date: 2002-08-13
Classification: B01L

Abstract:
A process for manufacturing a thermal cycler, comprising the sequential steps of:providing a silicon wafer having upper and lower surfaces; in said upper surface, etching two inner and two outer trenches to a first depth, said inner tenches having a first width and said outer trenches having second width; forming a first dielectric layer on said upper surface, including said trenches; depositing a layer of material suitable for use as a sensor and as a resistive heater; patterning and etching the material layer to form temperature sensors and heater elements; in said upper surface etching, to a second depth, two top preliminary trenches having a third width, each being located between an inner trench and an outer trench; patterning and etching said upper surface whereby a chamber trench, having a fourth width and located between said inner trenches, is formed to a third depth and the top preliminary trenches have their depth increased to a fourth depth; forming a second dielectric layer on said upper surface, including all trenches; patterning and etching the lower surface of the wafer to form an under-trench that is wide enough to slightly overlap the top preliminary trenches, to a depth such that the top preliminary trenches extend through said lower surface and, within the chamber trench, the wafer has a thickness that is between about 30 and 100 microns; providing a sheet of dielectric material and micro-machining said sheet to form holes in selected locations; and bonding the sheet to the wafer thereby forming a hermetically sealed chamber that is thermally isolated from the wafer.