CN-122016822-A - Ultraviolet LED module light homogenizing control system for semiconductor wafer defect detection

CN122016822ACN 122016822 ACN122016822 ACN 122016822ACN-122016822-A

Abstract

The invention discloses an ultraviolet LED module light homogenizing control system for detecting defects of a semiconductor wafer, which relates to the technical field of semiconductor manufacturing detection and comprises an ultraviolet LED array module for generating an ultraviolet detection light source and projecting the ultraviolet detection light source to the surface of the wafer, a multidimensional parameter sensing module for acquiring the physical state of the module and outputting light field parameters in real time, a dynamic driving control module for performing high-precision modulation on driving current, a central processing and light homogenizing algorithm module for receiving sensing data and generating a regulating instruction based on a built-in algorithm strategy, and an active heat management module for maintaining stable light emitting wavelength and power. The invention changes the traditional open-loop control mode, realizes the closed-loop real-time sensing and dynamic compensation of the drift of the ultraviolet light field in space and time dimension, thoroughly solves the problems of unstable light intensity and distribution distortion caused by chip aging attenuation and thermal effect, maintains the uniform light detection background with extremely high precision for a long time, and greatly improves the accuracy and the intelligent level of wafer defect detection.

Inventors

YONG HAI
LI XIAOQING
WANG HUA
CHEN LIN

Assignees

深圳市美耐斯光电有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafers is characterized by comprising an ultraviolet LED array module, a multi-dimensional parameter sensing module, a dynamic driving control module, a central processing and light homogenizing algorithm module and an active type heat management module, wherein the ultraviolet LED array module is used for generating an ultraviolet detection light source with a preset wavelength range and projecting the ultraviolet detection light source to the surfaces of the wafers to be detected, the multi-dimensional parameter sensing module is used for acquiring physical state parameters and output light field parameters of the ultraviolet LED array module in real time, the dynamic driving control module is used for carrying out high-precision modulation on driving current of the ultraviolet LED array module according to an adjusting instruction, the central processing and light homogenizing algorithm module is used for receiving data fed back by the multi-dimensional parameter sensing module, generating the adjusting instruction through executing the built-in light homogenizing algorithm and sending the adjusting instruction to the dynamic driving control module, and the active type heat management module is used for carrying out temperature adjustment on the ultraviolet LED array module so as to maintain stability of light emitting wavelength and light output power.
2. The LED module light homogenizing control system for detecting the defects of the semiconductor wafer according to claim 1, wherein the LED array module comprises a plurality of LED units which are arranged in a regular hexagonal honeycomb shape, each LED unit is packaged on an aluminum nitride ceramic substrate with high heat conductivity, a fly eye lens group made of synthetic quartz material is arranged on the light emitting side of the LED array module, and the fly eye lens group is used for carrying out integral homogenization treatment on discrete light beams emitted by the LED units to form rectangular uniform light fields on the surface of the wafer to be detected.
3. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafers according to claim 2 is characterized in that the dynamic driving control module comprises multiple independent constant current driving modules, each constant current driving module is used for respectively controlling one group of ultraviolet LED units in the ultraviolet LED array module, the dynamic driving control module can realize step-type adjustment of driving current through a pulse width modulation technology and monitor the waviness of output current in real time through an internally integrated high-frequency sampling module, and the dynamic driving control module also adopts a pulse width modulation technology of cross phase staggering to control pulse rising edges of the driving current of each light emitting unit group to be staggered on a time axis.
4. The system for controlling the light uniformity of the ultraviolet LED module for detecting the defects of the semiconductor wafer according to claim 3, wherein the central processing and light uniformity algorithm module is provided with a fault early warning and redundancy complementation mechanism, when the driving current of one ultraviolet LED unit reaches the upper limit of the safety limit value and the corresponding local area light intensity is still lower than 90% of the target value, the system judges that the ultraviolet LED unit breaks down and sends a maintenance request signal to the outside, and meanwhile, the central processing and light uniformity algorithm module automatically adjusts the output power of the adjacent ultraviolet LED units around the fault unit, and fills the light intensity hole by utilizing the light spot overlapping effect of the regular hexagon honeycomb arrangement structure.
5. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafers is characterized in that the multidimensional parameter sensing module comprises a light intensity space distribution sensor array, a spectrum monitoring unit and a temperature sensing array, wherein the light intensity space distribution sensor array is composed of a plurality of silicon carbide photodiodes distributed at the edge of a fly-eye lens group and in an effective view field range and used for acquiring real-time irradiance of different positions of a light field, the spectrum monitoring unit adopts a micro spectrometer architecture and is used for extracting central wavelength offset of the ultraviolet LED array module, and the temperature sensing array comprises a thermistor clung to the bottom of each ultraviolet LED unit and used for acquiring luminous junction temperature.
6. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafer according to claim 5, wherein the active heat management module comprises a micro-channel liquid cooling radiator and an adaptive air cooling assembly, the central processing and light homogenizing algorithm module adjusts the circulation rate of cooling liquid and the rotating speed of a fan in real time through feedback logic, when the spectrum monitoring unit monitors that the wavelength deviation exceeds a preset nanometer value, the central processing and light homogenizing algorithm module judges the deviation reason by combining the current junction temperature data, wherein the cooling power of the active heat management module is increased if the heat effect is judged to be caused, and the waveform slope of the driving current is finely adjusted through the dynamic driving control module if the electric stress is judged to be caused.
7. The system of claim 6 wherein the CPU and light homogenizing algorithm module has a deep aging compensation mode, and is capable of controlling the active heat management module to change the flow of the cooling liquid to produce a controlled temperature gradient, and differentiating the aging causes by analyzing the light intensity response sensitivity drift of each UV LED unit at different temperatures, wherein the dynamic driving control module reduces the duty ratio of pulse width modulation and increases the peak current of pulse for attenuation caused by thermal resistance increase, and the dynamic driving control module adopts a driving mode of increasing the base value DC current and superposing small pulses for attenuation caused by aging of the active region itself.
8. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafer according to claim 5, wherein a preset gold standard light field distribution model is stored in the central processing and light homogenizing algorithm module, and in the running process of the system, the central processing and light homogenizing algorithm module compares real-time light intensity data fed back by the light intensity space distribution sensor array with the gold standard light field distribution model, and calculates light intensity deviation values of all space coordinate points by using a differential analysis method.
9. The ultraviolet LED module dodging control system for semiconductor wafer defect detection as recited in claim 8, wherein said dodging control strategy comprises a spatial uniformity compensation algorithm and a temporal stability compensation algorithm; the space uniformity compensation algorithm identifies a corresponding ultraviolet light emitting diode unit group aiming at a region with the light intensity lower than a preset threshold value by establishing a mapping matrix of the driving current and the space light intensity contribution quantity, and instructs a dynamic driving control module to increase the driving current duty ratio of the ultraviolet light emitting diode unit group; The time stability compensation algorithm is based on a built-in luminous attenuation prediction model, calculates compensated target driving power by combining the accumulated running time of the ultraviolet light emitting diode unit and real-time temperature data, and the compensation calculation principle is as follows: In the formula, Representing the target driving power after the current time t is compensated; representing a reference power reference under the gold standard; representing the intrinsic aging attenuation coefficient of the ultraviolet light emitting diode; Is a temperature drift correction coefficient; is the difference between the real-time junction temperature and the standard operating temperature.
10. The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafer according to claim 9, wherein the system further comprises a high-speed communication interface, the central processing unit and the light homogenizing algorithm module synchronously acquire real-time position information of the objective table through the high-speed communication interface, when the transient process of mechanical vibration is judged, a vibration displacement compensation table in a memory is called, a vibration compensation gain factor is calculated in real time, and feedforward adjustment is carried out on current pulses output by the dynamic driving control module.

Description

Ultraviolet LED module light homogenizing control system for semiconductor wafer defect detection Technical Field The invention belongs to the technical field of semiconductor manufacturing detection, and particularly relates to an ultraviolet LED module light homogenizing control system for detecting defects of a semiconductor wafer. Background In the manufacturing process of semiconductor integrated circuits, wafer surface defect detection is a core link for guaranteeing the yield and reliability of products. Along with the progress of the process procedure to the nanometer level, the detection system has very high requirements on the wavelength characteristics, stability and irradiation precision of the light source, and the ultraviolet band light source has become an indispensable key technical support in the field of fine defect detection due to the high resolution advantage caused by the short wavelength of the ultraviolet band light source. The ultraviolet LED module is used as a new generation solid state lighting source, and gradually replaces the traditional gaseous light source such as mercury lamp by virtue of the characteristics of low power consumption, fast response, customizable wavelength and the like. The module is arranged in an array and optically shaped, and aims to provide highly uniform and stable light field distribution for a wafer detection plane, so that a necessary optical background is provided for the image acquisition system to extract weak defect signals. The prior art mostly adopts an open-loop control mode based on preset parameters, and faces serious technical challenges in the long-term operation process. Because the ultraviolet LED chip is subject to photoelectric conversion efficiency and thermal effect, the output light intensity of the ultraviolet LED chip is easy to generate irreversible aging attenuation along with the accumulation of working time, and the fluctuation of ambient temperature and the transient instability of driving current can lead to the deflection of a luminous center and the distortion of light field distribution. The lack of the control mode of real-time feedback and dynamic compensation makes the uniformity of the light field difficult to maintain constant in the production process, is extremely easy to cause misjudgment or missing detection of the detection system, and requires frequent complex manual calibration and parameter reset in the follow-up process, thereby severely restricting the overall operation efficiency and the intelligent level of the semiconductor detection flow. Disclosure of Invention The invention aims to provide an ultraviolet LED module light homogenizing control system for detecting defects of a semiconductor wafer, which is used for solving the technical problems of the prior art that the ultraviolet LED module is unstable in light intensity and distorted in light field distribution caused by chip aging attenuation and thermal effect in the long-term operation process, so that the wafer detection accuracy is reduced and manual calibration is frequent. The technical scheme of the invention is as follows: The ultraviolet LED module light homogenizing control system for detecting the defects of the semiconductor wafer comprises an ultraviolet LED array module, a multidimensional parameter sensing module, a dynamic driving control module, a central processing and light homogenizing algorithm module and an active type heat management module, wherein the ultraviolet LED array module is used for generating an ultraviolet detection light source in a preset wavelength range and projecting the ultraviolet detection light source to the surface of the wafer to be detected, the multidimensional parameter sensing module is used for acquiring physical state parameters and output light field parameters of the ultraviolet LED array module in real time, the dynamic driving control module is used for carrying out high-precision modulation on driving current of the ultraviolet LED array module according to an adjusting instruction, the central processing and light homogenizing algorithm module is used for receiving data fed back by the multidimensional parameter sensing module, generating the adjusting instruction through executing a built-in light homogenizing control strategy and sending the adjusting instruction to the dynamic driving control module, and the active type heat management module is used for carrying out temperature adjustment on the ultraviolet LED array module so as to maintain stability of light emitting wavelength and light output power. The ultraviolet light-emitting diode array module comprises a plurality of ultraviolet light-emitting diode units which are arranged in a regular hexagonal honeycomb shape, wherein each ultraviolet light-emitting diode unit is packaged on an aluminum nitride ceramic substrate with high heat conductivity, a fly eye lens group made of artificial synthetic quartz materials is arranged on t