Columbia Technology Ventures

High-density bioelectric sensor using CMOS-integrated Junctional Field Effect Transistors (JFETs)

This technology describes a CMOS-integrated Junctional Field Effect Transistors (JFETs) with low flicker noise for use in bioelectric sensing applications.

Unmet Need: Trade-off between transistor packing density and signal flicker noise

High-resolution measurement of bioelectric signals using electronic arrays requires a large number of very small transistor-based sensors. However, the scaling down of conventional Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) sensors often amplifies the flicker noise associated with the measurement, corrupting the already weak signals from electronic-biophysical interfaces. Although JFETs exhibit decreased flicker noise compared to MOSFET, fabrication of JFET sensors using conventional CMOS techniques is difficult.

CMOS-compatible JFET component is 20 times smaller than MOSFET designs with similar noise levels

The JFETs described in this technology can achieve a noise target comparable to that of a MOSFET while occupying an area 20 times smaller. The technology also further reduces the complexity of bioelectric sensing systems by removing the need for additional noise reduction techniques often used to combat flicker noise. Since flicker noise varies inversely with the area of a transistor, it is of particular concern in electronic interfaces to biophysical systems that require high density transistor arrays. JFETs display lower levels of flicker noise compared to other transistor designs because of their unique construction. Although JFETs are widely available as discrete components, large-scale fabrication using commercial CMOS technology has been limited. This technology presents a design specifically tailored for CMOS fabrication to enable the commercial fabrication of high density bioelectric sensing arrays. Such high-resolution measurements may be of particular importance in applications such as biochemical assays and neuronal recordings.

Applications:

  • High density, low noise bioelectric sensing arrays
  • Accurate sensors for biological/electrochemical assays and genomic sequencing applications
  • Compact brain-machine interface (BMI) systems
  • CMOS-compatible JFET fabrication technique

Advantages:

  • Integrated JFET design fabricated using CMOS technology
  • Optimized to enable the fabrication of dense arrays of transistors for use in sensor arrays
  • Low flicker noise characteristics of JFETs simplify sensor array design by avoiding the need for additional noise mitigation techniques

Lead Inventor:

Kenneth Shepard, Ph.D.

Patent Information:

Patent Issued

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