Schottky diode temperature sensor for pressure sensor

TL;DR

This paper presents a miniaturized Schottky diode-based temperature sensor integrated with a pressure sensor, demonstrating accurate temperature measurement and compensation capabilities over a wide temperature range.

Contribution

It introduces a novel small silicon Schottky diode chip for temperature sensing that functions effectively under pressure sensor operating conditions.

Findings

Achieved a temperature coefficient of -1.635 mV/°C with high linearity.

Demonstrated high breakdown voltage and low leakage current.

Proved effective temperature measurement from -65°C to +115°C.

Abstract

The small silicon chip of Schottky diode (0.8x0.8x0.4 mm3) with planar arrangement of electrodes (chip PSD) as temperature sensor, which functions under the operating conditions of pressure sensor, was developed. The forward I-V characteristic of chip PSD is determined by potential barrier between Mo and n-Si (ND = 3x1015 cm-3). Forward voltage UF = 208 mV and temperature coefficient TC = -1.635 mV/C (with linearity kT <0.4% for temperature range of -65 to +85 C) at supply current IF = 1 mA is achieved. The reverse I-V characteristic has high breakdown voltage UBR > 85 V and low leakage current IL < 5 {\mu}A at 25 C and IL < 130 {\mu}A at 85 C (UR = 20 V) because chip PSD contains the structure of two p-type guard rings along the anode perimeter. The application of PSD chip for wider temperature range from -65 to +115 C is proved. The separate chip PSD of temperature sensor located at a distance of less than 1.5 mm from the pressure sensor chip. The PSD chip transmits input data for temperature compensation of pressure sensor errors by ASIC and for direct temperature measurement.