Method of manufacturing miniaturized components of chemical and biological detection sensors that employ ion-selective membranes, and supports for such components
OwnerMeinhard Knollinventor
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Abstract
The invention relates to a process for producing miniaturized chemical and biological sensor elements with ion-selective membranes. To simplify production in the micro range, an aperture (5,6) starting from the front (3) and tapering toward the back (4) is made in a thin silicon substrate (1) so that the front and back are interconnected. A liquid with which the ion-selective membrane is formed is poured into the containment (2) thus formed. Vertical ISFETs may also be made on the above principle.
Claims33
In a method of manufacturing supports for miniaturized components of sensors that detect chemicals and biologicals by means of ion-selective membranes, said method comprising the following steps:
- (a) producing a thin substrate of a single-crystal silicon having a front side and a back side and having one of a (100) and a (110)-orientation in its plane,
- (b) etching said substrate anisotropically from the front side to the back side, thereby forming an opening that tapers from the front side to the back side in the form of a truncated pyramid, when etched in a silicon substrate having a (100)-orientation, and an opening with two parallel as well as perpendicular walls and two sloping walls when etched in a silicon substrate having a (110)-orientation, said opening forming a containment;
- the improvement wherein
- (1) at least one electrode is applied against one of the internal walls of the opening;
- (2) a liquid solution is introduced into the containment from the front side, said solution comprising one of a polymer in a solvent which is allowed to evaporate and a solution which is allowed to solidify into an hydrogel;
- and
- (3) leaving the solidified polymer or hydrogel as ion-selective membrane within the containment and with contact with the electrode.
A method of manufacturing a vertical ISFET on a thin silicon substrate having a front side and a back side comprising the steps of (1) providing the front side of the silicon substrate with superimposed positive and negative layers constituting a source, drain and gate;
- (2) producing in the substrate an opening that tapers from the front side to the back side and provides communication and containment therebetween, and (3) introducing a-liquid into the containment opening to form an ion-selective membrane, wherein the containment is anisotropically etched, sloping together through the layers, and accommodates the ion-selective membrane, and wherein walls of the containment are provided with a dielectric layer.
Dependencies are inferred from the claim text.