Biological material sensing semiconductor device

A method of making a semiconductor device, comprising:

• forming a transistor on a substrate, the transistor including a gate;
• forming a multi-layer interconnect (MLI) over the transistor, the MLI including a stack of one or more electrically conductive layers within an interlayer dielectric (ILD), the electrically conductive layers being electrically connected to one another through one or more MLI vias extending through the ILD between the electrically conductive layers;
• forming a via in the ILD above the MLI, the via being electrically coupled through the MLI to the gate of the transistor, the via having one or more side walls and an end-most surface;
• etching a well within the ILD, the well having an opening and a floor to define an open-ended cavity into which a fluid may be selectively flowed, and also having a notch in a sidewall of the well, the notch being located along the floor;
• wherein the etching results in the one or more side walls and the end-most surface of the via extending above the floor of the well;
• and
• forming a sensing layer that directly contacts the floor of the well, the one or more side walls of the via, and at least a portion of the end-most surface of the via extending above the floor of the well, and that fills the notch, and that does not extend up the sidewall of the well, the sensing layer being reactive to exposure to a biological material.

A method of making a semiconductor device, comprising:

• forming a transistor on a substrate, the transistor including a gate;
• forming a material layer over the transistor;
• forming a via that is electrically coupled to the gate of the transistor within the material layer;
• etching a well within the material layer, the well having an opening and a floor to define an open-ended cavity into which a fluid may be selectively flowed, and also having a notch in a sidewall of the well, the notch being located along the floor, and wherein one or more sidewalls of the via and an end-most surface of the via extend above the floor of the well;
• and
• forming a sensing layer over the via, the sensing layer being reactive to exposure to a biological material, wherein the sensing layer directly contacts the floor of the well and the one or more side walls of the via and covers at least a portion of the end-most surface of the via extending above the floor of the well, and also fills the notch and does not extend up the sidewall of the well.