Voltage Application Device Waveform Control for Semiconductor Testing
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Solution Overview
Problem
The existing voltage application devices in semiconductor wafer testing suffer from deteriorated rising waveforms of output voltage, leading to potential DUT malfunction due to overshoot, which is not effectively addressed by prior techniques that apply voltage in a stepwise manner without proper time management.
Innovation Solution
A voltage application device with a voltage setting unit that sets the number of transient steps, step time, and step voltage to form a step-like transient voltage waveform, ensuring the end point of each step time is between the rising time and overshoot time in the step response curve of a high-order lag system, thereby preventing overshoot and achieving a set voltage value quickly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a phase compensation circuit is optimized for a configuration with a large-capacity load connected, then the rising waveform of the output voltage improves for that configuration, but the rising waveform deteriorates when no large-capacity load is connected, causing overshoot
Solution Approach 1:
The invention dynamically switches between different phase compensation circuits based on the connected load configuration. The voltage application device selects an first phase compensation circuit when a large-capacity load is connected and an second phase compensation circuit when no large-capacity load is connected, allowing the system to adapt its characteristics to match the actual load conditions and maintain optimal rising waveform quality in both scenarios
Solution Approach 2:
The invention changes the parameters of the phase compensation circuit by selecting different circuits with different parameter configurations. The first phase compensation circuit has parameters optimized for large-capacity load configurations, while the second phase compensation circuit has parameters optimized for configurations without large-capacity loads, thereby resolving the contradiction between optimizing for one configuration versus adapting to different configurations
2Manufacturing precision
If the rising waveform of the output voltage is improved by circuit optimization, then the voltage application precision improves, but the time to reach the set voltage value increases
Solution Approach 1:
The invention segments the voltage application process into multiple transient steps with different step voltages and step times. By dividing the voltage transition into discrete steps rather than a continuous ramp, the system can precisely control the voltage application while maintaining a reasonable time to reach the set voltage value, thus balancing precision and speed
3Manufacturing precision
If a stepwise voltage application method is used to prevent overshoot, then the rising waveform quality improves, but the time to reach the set voltage value increases significantly
Solution Approach 1:
The invention dynamically adjusts the step time and step voltage parameters based on the actual load configuration and system response characteristics. By making the voltage application process adaptive rather than fixed, the system can prevent overshoot while minimizing the time to reach the set voltage value, resolving the contradiction between waveform quality and response time
Data Source
AI summary
A voltage application device of a tester includes a voltage setting controller that sets a number of transient steps, step time, and step voltage as transient voltage setting parameters; and a device power supply (DPS) configured to supply power to the plurality of devices under test formed on a substrate. The voltage application device outputs an output voltage having a step-like transient voltage waveform based on the transient voltage setting parameters set by the voltage setting controller. The voltage application device is a high-order lag system of a second-order or higher in which an overshoot occurs in a response with respect to a set voltage. An end point of a step time of each of the transient steps set in the voltage setting controller is set to be a time between an end point of a rising time and an overshoot time.