CN-122017931-A - Beam distribution measuring device and method of semiconductor beam equipment

CN122017931ACN 122017931 ACN122017931 ACN 122017931ACN-122017931-A

Abstract

The application discloses a beam current distribution measuring device and method of semiconductor beam current equipment, belonging to the technical field of semiconductor beam current measurement. The vacuum displacement platform carries a collimation plate provided with a flow collimation small hole, the collimation plate can scan and move in a two-dimensional plane perpendicular to the beam direction with high precision, the Faraday probe is fixedly arranged at the downstream of the displacement platform, a collecting polar plate of the Faraday probe is opposite to the beam collimation small hole, the bottom of the collecting polar plate is provided with a magnet array and is connected with a bias voltage circuit to form an electromagnetic dual secondary electron suppression structure, a standby polar plate is used for detecting penetrating beam and triggering interlocking, the beam measurement electronic system comprises a beam measurement electronic board card and a CPCI case multichannel acquisition board card, and the upper computer performs data processing and beam spot inversion to obtain a beam distribution diagram. The application realizes the high-precision, high signal-to-noise ratio and multi-parameter on-line measurement of beam current distribution in semiconductor ion implantation and etching equipment.

Inventors

WAN LEI
WU YALONG
XU DEHAO
WANG YINHUI
CHEN YE
WANG ZHIYU
FU HAORAN
CAI XIAOWEI
Zhai Gangjia
Meng Huina

Assignees

国电投核力电科(无锡)技术有限公司

Dates

Publication Date: 20260512
Application Date: 20260224

Claims (10)

1. A beam current distribution measuring apparatus of a semiconductor beam current device, comprising: The displacement platform is arranged in the vacuum chamber, a collimation plate is carried on the displacement platform, a beam collimation small hole is formed in the middle of the collimation plate, and the displacement platform is used for driving the collimation plate to scan and move in a two-dimensional plane perpendicular to the beam direction; the Faraday probe is fixedly arranged at the downstream of the displacement platform and comprises a collecting polar plate and a standby polar plate positioned at the rear of the collecting polar plate, wherein the collecting polar plate is opposite to the light emitting side of the beam collimation small hole and is used for collecting a beam signal passing through the beam collimation small hole and converting the beam signal into a current signal to be output; The beam measurement electronic system is respectively and electrically connected with the Faraday probe and the displacement platform, and comprises a beam measurement electronic board card and a CPCI case multichannel acquisition board card, wherein the beam measurement electronic board card is used for receiving the current signals; the upper computer is in communication connection with the beam measurement electronic system and is used for receiving the packed data, executing a beam spot inversion algorithm to reconstruct two-dimensional distribution of beam current and carrying out visual display.
2. The beam profile measuring apparatus of semiconductor beam equipment according to claim 1, wherein the collimating plate is a silicon carbide collimating plate, a compact coating is formed on the surface of the collimating plate through a SiC-CVD process, the beam collimating apertures are tapered through-hole structures, and the collimating plate is a detachable structure to replace the beam collimating apertures with different apertures.
3. The beam current distribution measuring device of the semiconductor beam current equipment according to claim 1, wherein the magnet array is a permanent magnet with checkerboard N/S poles arranged in a staggered manner, and the bias voltage circuit is used for applying 0-100V adjustable positive bias voltage to the collecting polar plate.
4. The beam current distribution measuring apparatus of a semiconductor beam current device according to claim 1, wherein the faraday probe further comprises: The shielding housing is used for covering the collecting polar plate, the standby polar plate and the magnet array, and a silicon carbide baffle is fixed at the top of the shielding housing; And the insulating support columns are used for realizing electrical isolation among the collecting polar plate, the standby polar plate and the shielding housing.
5. The beam profile measuring apparatus of a semiconductor beam device of claim 1, wherein the beam measuring electronics board card is integrated with: the current-voltage conversion circuit comprises a transimpedance amplification path and an integral amplification path and is used for realizing instantaneous intensity measurement or integral dose measurement of the current signal according to measurement mode switching; A bias circuit for generating a bias voltage; The isolation operational amplifier and the second-order active low-pass filter circuit are used for isolating voltage signals and suppressing noise.
6. The beam profile measuring apparatus of the semiconductor beam device according to claim 5, wherein the beam measuring electronics board card has three switchable measuring modes: The integral measurement is switched to an integral amplification path, and the integral amplification path is used for carrying out integral amplification on the beam current under the fixed integral time to carry out voltage-current conversion, and the charged voltage of the capacitor is used for evaluating the beam current dosage; the measurement of the collecting polar plate is switched to a transimpedance amplification passage for measuring the instantaneous current intensity of the beam output by the collecting polar plate in real time; And the standby polar plate is used for measuring the instantaneous current intensity output by the standby polar plate in real time, and when the current signal exceeds a preset threshold value, the CPCI case multi-channel acquisition board card triggers interlocking and reports the interlocking to the upper computer.
7. The beam profile measuring apparatus of claim 1, wherein the CPCI chassis multi-channel comprises: the control processing module comprises a Field Programmable Gate Array (FPGA) chip, wherein an analog-to-digital converter and a digital-to-analog converter are arranged in the FPGA chip; And the data acquisition module is used for data processing and beam spot inversion.
8. The beam current distribution measuring apparatus of the semiconductor beam current device according to claim 1, wherein the upper computer comprises: the parameter configuration module is used for setting a scanning range, a sampling step length, a motor speed, a measurement mode and a bias voltage value; The data processing and inverting module is used for executing background subtraction, a matrix inversion algorithm based on space mapping or a two-dimensional Gaussian convolution fitting algorithm based on a point spread function to generate a beam two-dimensional density thermodynamic diagram and an X/Y direction profile curve; The characteristic calculation module is used for calculating barycentric coordinates, half-width and Gaussian fitting goodness of the beam spots; And the alarm and interlocking module is used for sending an alarm instruction and triggering interlocking when the signal of the standby polar plate exceeds the limit, the motor is abnormal or the analog-to-digital conversion exceeds the range.
9. A beam current distribution measuring method of a semiconductor beam current apparatus, using the beam current distribution measuring device of a semiconductor beam current apparatus according to any one of claims 1 to 8, comprising: setting measurement parameters through the upper computer and issuing the measurement parameters to the CPCI case multi-channel acquisition board card, wherein the CPCI case multi-channel acquisition board card configures a movement track of the displacement platform and a measurement mode of the beam measurement electronics board card according to the parameters; Controlling the displacement platform to drive the collimation plate, so that the beam collimation small hole continuously scans in an XY plane perpendicular to the beam transmission direction according to a preset path; The Faraday probe collects beam signals passing through the beam collimation small holes in real time, and the collecting polar plate outputs current signals generated by beam bombardment to the beam measurement electronics board card through a low-noise transmission cable; the beam measurement electronics board card performs current-voltage conversion, isolation amplification, filtering and analog-to-digital conversion on the current signal according to the current measurement mode to generate a digital sampling value; The CPCI chassis multi-channel acquisition board is clamped in a one-time scanning period, position closed-loop control of the displacement platform and trigger sampling of the analog-to-digital converter are synchronously executed, digital sampling values of each sampling point are associated with corresponding two-dimensional coordinates and then stored in a cache, and all data are packed and uploaded to the upper computer after scanning is completed; And the upper computer receives the packed data, solves the beam intensity of each grid position in the measurement area by adopting an inversion algorithm, and reconstructs and displays a two-dimensional distribution map of the beam.
10. The beam profile measurement method of a semiconductor beam device of claim 9, wherein the inversion algorithm is a matrix inversion algorithm or a point spread function convolution fitting algorithm.

Description

Beam distribution measuring device and method of semiconductor beam equipment Technical Field The application belongs to the technical field of beam measurement in semiconductor beam equipment such as an ion implanter, an ion beam etching machine and the like, and particularly relates to a beam distribution measuring device and method of the semiconductor beam equipment. Background The ion implantation and etching process is a key link in the production and manufacture of semiconductor devices, and in the ion implantation and some special etching processes, a required ion beam current is generated through an ion source, and the ion beam current is accelerated through an accelerator section or led out through an electric field to perform ion implantation or etching process on the surface of a silicon wafer or a solid target. With the development of semiconductor technology, the requirements on the production process and the production efficiency are increasing. The method needs a more accurate and effective beam current distribution measurement means, the dose injected into each chip or the surface etching process needs to be highly accurately and uniformly distributed, the dose is not accurate, the device is invalid, the uniformity is poor, the performance difference between the chips is caused, and the yield is directly reduced. The method has the advantages that the dosage control and uniformity are ensured, the profile and the stability of the beam are also required to be monitored, the abnormal beam shape such as hollow and asymmetric is often indicative of the faults of an ion source, a lead-out system or a focusing system, the mass production accidents can be avoided by diagnosing in advance, and the preventive maintenance is guided. Meanwhile, in order to meet the special requirements in the semiconductor industry, the beam measuring device is developed and the corresponding measuring method is perfected according to the special working conditions under different application scenes. Disclosure of Invention The application aims to solve the technical defects of low spatial resolution, poor anti-interference capability, single function and no real-time feedback in the prior art, and provides a beam current distribution measuring device and method of semiconductor beam current equipment, which realize high-precision, high signal-to-noise ratio and multi-parameter online measurement of beam current distribution in semiconductor ion implantation and etching equipment. The technical proposal is as follows: in one aspect, there is provided a beam profile measuring apparatus of a semiconductor beam device, including: The displacement platform is arranged in the vacuum chamber, a collimation plate is carried on the displacement platform, a beam collimation small hole is formed in the middle of the collimation plate, and the displacement platform is used for driving the collimation plate to scan and move in a two-dimensional plane perpendicular to the beam direction; the Faraday probe is fixedly arranged at the downstream of the displacement platform and comprises a collecting polar plate and a standby polar plate positioned at the rear of the collecting polar plate, wherein the collecting polar plate is opposite to the light emitting side of the beam collimation small hole and is used for collecting a beam signal passing through the beam collimation small hole and converting the beam signal into a current signal to be output; The beam measurement electronic system is respectively and electrically connected with the Faraday probe and the displacement platform, and comprises a beam measurement electronic board card and a CPCI case multichannel acquisition board card, wherein the beam measurement electronic board card is used for receiving the current signals; the upper computer is in communication connection with the beam measurement electronic system and is used for receiving the packed data, executing a beam spot inversion algorithm to reconstruct two-dimensional distribution of beam current and carrying out visual display. The application solves the industry commonality problems of low resolution, poor interference resistance, single function and no real-time feedback in the semiconductor beam measurement by the whole technical proposal of the aperture scanning, electromagnetic dual-inhibition Faraday probe, beam measurement electronics system and matrix inversion algorithm, and realizes the high-precision, high signal-to-noise ratio, multi-parameter and intelligent beam distribution on-line measurement. By adopting a 'small hole scanning+matrix inversion' architecture, beam current is spatially limited by using beam current collimation small holes with the aperture of 3mm, and the equivalent position resolution capability less than or equal to 0.5mm can be realized by combining a matrix inversion algorithm or a point spread function convolution fitting algorithm based on spatial mapping, so that the physica