On-Chip Temperature Sensor Protection Using Bidirectional Zener Clamps
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Solution Overview
Problem
Conventional semiconductor devices lack effective protection against electro-static discharge (ESD) for temperature sensing units, which can lead to damage and deterioration of their characteristics.
Innovation Solution
Incorporating a bidirectional diode unit, specifically a Zener diode connected in a serial bidirectional way between the anode and cathode pads, and a protective diode unit connected in an antiparallel direction to the temperature sensing unit, to prevent overvoltage and excessive current from ESD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature detecting diode is provided in a semiconductor device, then temperature sensing capability is improved, but the device becomes vulnerable to electro-static discharge damage
Solution Approach 1:
A bidirectional diode unit is introduced as an intermediary protective element connected between the temperature sensing unit and the front surface electrode. This mediator clamps voltage spikes and dissipates ESD energy, protecting the temperature sensing diode from damage while allowing temperature measurement functionality to remain intact.
Solution Approach 2:
The bidirectional diode unit is pre-configured in the circuit path before ESD events can occur. It establishes a protective mechanism that activates automatically upon voltage threshold exceedance, cushioning the temperature sensing unit against ESD damage before the harmful effects can manifest.
2Reliability
If protective diodes are added to protect the temperature sensing unit, then ESD resistance is improved, but device complexity increases
Solution Approach 1:
The bidirectional diode unit combines multiple protective functions into a single integrated component. By using a bidirectional configuration, it protects against both positive and negative voltage spikes simultaneously, eliminating the need for separate protective diodes for each polarity and simplifying the overall circuit structure.
Solution Approach 2:
The bidirectional diode unit serves multiple protective functions: it acts as a voltage clamp, ESD protector, and overvoltage safeguard for the temperature sensing unit. This multi-functional approach reduces the total number of components needed compared to using separate dedicated protectors for each function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The bidirectional diode unit effectively protects the temperature sensing unit from ESD, maintaining its characteristics and improving the semiconductor device's ESD withstand capability while allowing for downsizing and efficient circuit layout.
Implementation Method 1
a bidirectional diode unit electrically connected in a serial bidirectional way between the cathode pad and the front surface electrode
Data Source
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AI summary
A semiconductor device including: a semiconductor substrate; a temperature sensing unit provided on a front surface of the semiconductor substrate; an anode pad and a cathode pad electrically connected with the temperature sensing unit; a front surface electrode being set to a predetermined reference potential; and a bidirectional diode unit electrically connected in a serial bidirectional way between the cathode pad and the front surface electrode is provided. The bidirectional diode unit may be arranged between the anode pad and the cathode pad on the front surface.