TECHNICAL FIELD

The present disclosure relates generally to electronic sensors and more particularly to nanogap sensors or transducers, and methods of forming the same.

BACKGROUND

Electronic sensors such as nanogap sensors may be used to detect electrochemical tags (e.g., markers or indicators) which has many important applications such as, for example, molecular detection and analysis, molecular diagnostics, disease detection, substance identification, and DNA detection and sequencing. For example, in next generation DNA sequencing, CMOS technology may be employed to form the nanogap sensors. The nanogap sensors are arranged horizontally over an integrated circuit (IC) chip using complementary metal oxide semiconductor (CMOS) processes, where each nanogap sensor includes two planar electrodes arranged over the chip and are separated by a nanoscale gap. Such nanogap sensors employ redox cycling to amplify signals. For example, by properly biasing the two electrodes, redox-active molecules can be repeatedly oxidized at one electrode and reduced at the other, contributing a plurality of electrons to the recorded current and resulting in the net amplification of the signal (e.g., presence of the redox-active molecules). However, existing nanogap sensors have finite dead volumes which interrupts the redox process. For example, a dead volume may be formed by non-overlap regions of the two electrodes. The dead volume causes the redox process to stop when molecules are located at the dead volumes, which reduces and limits the redox cycling efficiency of the nanogap sensors such as in electrochemical DNA sequencing and lowers the observed signal (e.g., current). Furthermore, existing processes for forming the nanogap sensors are complicated and require additional masks and polishing steps.

From the foregoing discussion, it is desirable to provide an electronic sensor which addresses the above-mentioned challenges.

SUMMARY

Embodiments generally relate to semiconductor devices and method for forming the semiconductor devices. According to various non-limiting embodiments, a device may include a substrate having conducting lines thereon. One or more fin structures may be arranged over the substrate. Each fin structure may include a sensor arranged over the substrate and around the fin structure. The sensor may include a self-aligned first sensing electrode and a self-aligned second sensing electrode arranged around the fin structure. The first sensing electrode and the second sensing electrode each may include a first portion lining a sidewall of the fin structure and a second portion arranged laterally from the first portion. At least the first portion of the first sensing electrode and the first portion of the second sensing electrode may define a sensing cavity of the sensor. The second portion of the first sensing electrode and the second portion of the second sensing electrode may be electrically coupled to the conducting lines.

According to various non-limiting embodiments, a device may include a substrate having conducting lines thereon. One or more fin structures may be arranged over the substrate. Each of the one or more fin structures may include a sensor arranged around the fin structure over the substrate. The sensor may include a self-aligned first sensing electrode and a self-aligned second sensing electrode arranged around the fin structure. The first sensing electrode and the second sensing electrode may define a vertical sensing cavity of the sensor around the fin structure, and the first sensing electrode and the second sensing electrode may be electrically coupled to the conducting lines.

According to various embodiments, a method of forming a device is provided. The method may include providing a substrate having conducting lines thereon. The method may include arranging one or more fin structures over the substrate, and arranging a sensor over the substrate and around each fin structure of the one or more fin structures. Arranging the sensor may include forming a self-aligned first sensing electrode and a second sensing electrode around the one or more fin structures. The first sensing electrode and the second sensing electrode each includes a first portion lining a sidewall of the fin structure and a second portion arranged laterally from the first portion. At least the first portion of the first sensing electrode and the first portion of the second sensing electrode define a sensing cavity of the sensor, and the second portion of the first sensing electrode and the second portion of the second sensing electrode are electrically coupled to the conducting lines.

These and other advantages and features of the embodiments herein disclosed, will become apparent through reference to the following description and the accompanying drawings. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.

