Sensing Chip Sensitivity via Threshold Voltage Determination

The patent applies preliminary cleaning actions before the in-situ deposition process. Specifically, the substrate is cleaned using oxygen plasma treatment and/or UV ozone treatment prior to forming the piezoelectric membrane. This preliminary cleaning removes organic contaminants and creates a clean surface, preventing impurities from attaching to the membrane during subsequent deposition, thereby maintaining detection accuracy while preserving process integration benefits

The patent converts the potentially harmful effect of using liquid piezoelectric suspension (which contains impurities) into a beneficial process by adding controlled cleaning steps. The oxygen plasma and UV ozone treatments are designed to selectively remove impurities while preserving the piezoelectric material formation, thus transforming the harmful impurity attachment issue into a controlled cleaning process that enhances overall device performance

The patent determines threshold voltage by systematically varying the applied voltage parameter and measuring the corresponding electric signal amplitudes. By establishing the relationship between voltage magnitude and signal response, the method identifies the threshold voltage where the sensing chip transitions from non-responsive to responsive state. This parameter-based approach enables standardized sensitivity calibration across batch-produced chips, improving detection accuracy while maintaining manufacturing efficiency

The threshold voltage determination process is designed to be self-calibrating for each sensing chip in the batch. Each chip undergoes automated voltage sweeping and signal measurement, with the threshold voltage automatically identified from the measured data without requiring manual intervention. This self-service approach minimizes operator involvement and standardizes the calibration process across production batches