Analysis of the core functions and technical principles of the chip aging tester
Chip aging tester is a key equipment for assessing the long-term reliability of chips in semiconductor manufacturing, and its core functions and technical principles revolve around accelerated aging simulation, failure mode screening and environmental adaptability verification. The following is a detailed analysis:
I. Core Functions
1. Accelerated Aging Simulation
Accelerates the aging process of the chip through high temperature, high humidity, high pressure and other environmental conditions to simulate the actual use of several years or even decades of life consumption. For example, high temperature aging test (HTOL) by placing the chip in the 125 ℃ ~ 150 ℃ environment for hundreds to thousands of hours, triggering material degradation, interface diffusion and other failure mechanisms, so as to quickly expose potential defects. 2.
2. Multi-dimensional environment simulation
supports precise control of multiple environmental parameters, including:
Temperature range: from -70℃ to +150℃, covering extreme hot and cold scenarios;
Humidity control: 20% to 98% relative humidity, simulating the impact of hot and humid environments on the chip package;
Voltage/current stress: applying voltage or current higher than normal operating conditions, accelerating the failure modes such as electromigration and gate oxygen breakdown.
3. Dynamic and static aging test
static aging: the chip runs for a long time under constant conditions, mainly used for screening early failure (such as leakage current anomalies);
dynamic aging: combined with the function test signals (such as clock signals, data streams), to verify the stability of the chip in the dynamic state of operation, to improve node coverage.
4. Real-time monitoring and data acquisition
integrates high-precision sensors to monitor chip power consumption, junction temperature, signal integrity and other parameters in real time, and record the data through the automated system to provide a basis for failure analysis. For example, the heating power is dynamically adjusted through the junction temperature feedback to ensure the uniformity of the aging process.
II. Technical Principles
1. Accelerated Aging Mechanism
Arrhenius Model: Based on the exponential relationship between temperature and reaction rate, material degradation is accelerated by increasing the temperature. For example, for every 10℃ increase in temperature, the aging rate is increased by about 2 times, thus shortening the test cycle.
Voltage acceleration effect: Applying high voltage accelerates electromigration and dielectric breakdown, and the reliability of the gate oxygen layer is assessed by monitoring the change of leakage current.
2. Environmental control technology
Independent temperature control system: Liquid or air cooling technology is used to regulate the temperature individually at the test station to solve the test deviation caused by uneven heat distribution of high power consumption chips. For example, a temperature control accuracy of ±0.5℃ is realized by the heater and cooling valve working together.
Humidity control module: Dynamically adjust the humidity through the steam generator and drying system to ensure the controllability of moisture absorption and expansion of packaging materials under high humidity environment.
3. Dynamic Signal Loading and Feedback
Functional Signal Generation: Built-in high-speed signal generator applies excitation signals several times the working frequency to the chip to simulate stress accumulation under high-frequency operation;
Closed-loop Feedback Mechanism: Adjusts the test parameters according to the chip's output signals, for example, dynamically compensates for voltage fluctuations in order to maintain stable test conditions.
4. Failure mode analysis technology
online monitoring: real-time capture of small parameter drift (e.g., leakage current from nA level to μA level) through high-precision current/voltage meters to identify potential defects;
data analysis algorithms: combining with statistical models (e.g., Weibull distribution) to predict the chip life and correlate the failure modes (e.g., metal migration, interfacial delamination) with process defects.
Technical Challenges and Innovative Directions
1. Heat dissipation control for high power chips
The aging test of high power chips (e.g., silicon carbide devices) requires the integration of a liquid cooling system to solve the interruption of testing caused by local overheating. 2.
2. Multi-chip heterogeneous package testing
For advanced packages (e.g. 3D stacking), it is necessary to develop multi-channel independently controlled test interfaces to support simultaneous aging and signal interconnection verification.
3. Intelligent test system
Combined with AI algorithms to optimize the test parameters, such as machine learning to predict the aging conditions, to reduce the test time and energy consumption.
Summary
The core value of the chip aging tester is to quickly screen failed chips and optimize reliability design through accelerated environment simulation and accurate data acquisition. Its technology principle integrates multi-disciplinary knowledge of material science, thermodynamics and electronic engineering, etc. The future development direction will focus on the breakthrough of higher precision, lower energy consumption and intelligent testing capability.
