CN-112670147-B - Method for automatically adjusting dosage uniformity by utilizing multi-pole magnetic rod spacing control

Abstract

The invention discloses a method for automatically adjusting dose uniformity by utilizing multi-pole magnetic rod spacing control. The method comprises measuring ion beam current initial value J 0 (1) when magnetic pole position is unchanged, setting the same magnetic pole spacing for each of the upper and lower n magnetic poles, collecting ion beam current value corresponding to each magnetic pole (two magnetic poles which do not interfere with each other can be collected simultaneously) by using mobile Faraday bidirectional measurement mode (2) Calculating the amplitude relation between the magnetic pole response and the magnetic rod spacing, and using the relation formula to calculate (3) iteratively, and using the initial beam flow average value And solving an overdetermined equation to calculate an optimal magnetic bar spacing value (4) of each magnetic pole, and verifying and debugging effects (5) on a machine line. And designing a plurality of adjusting modes, and selecting the optimal adjusting mode according to the current beam current state to perform dose uniformity adjustment. The invention relates to an ion implantation device and a least square algorithm, belonging to the field of semiconductor manufacturing.

Inventors

• DU QIN

Assignees

• 北京烁科中科信电子装备有限公司

Dates

Publication Date

20260512

Application Date

20191015

Claims (6)

1. 1. A method for automatically adjusting dose uniformity using multi-pole bar magnet spacing control, comprising: Measuring an initial value J 0 of the ion beam current when the positions of the multiple magnetic poles are unchanged; sequentially collecting ion beam values of which the intervals between every two magnetic poles are the same as those between magnetic bars; According to the amplitude relation of the response of the magnetic pole and the magnetic rod spacing calculated by the collected data, the mathematical model expression is as follows, assuming that the magnetic rod spacing is set to be equal to delta d: ; Wherein, the The ion beam current value when the magnetic rod spacing delta d is increased for the ith magnetic pole, Is that A i 、x i 、w i is the response mathematical model coefficient of the ith magnetic pole, and the mathematical model expression is used for solving the difference with J 0 through a fitting algorithm; Average value according to initial value of ion beam current by least square method Solving an overdetermined equation, and calculating an optimal bar magnet spacing value of each magnetic pole; The machine reads the calculation result, outputs the beam value and verifies the debugging effect.
2. 2. The method for automatically adjusting the dose uniformity by utilizing the spacing control of the magnetic rods with multiple magnetic poles according to claim 1, wherein the data acquisition is completed by controlling the distance between the magnetic rods with multiple magnetic poles, the dose uniformity is calculated, the calculation accuracy is high, the data acquisition is performed through repeated iterative calculation, the program running speed is greatly improved, and the dynamic adjustment of the dose uniformity of the ion beam is realized.
3. 3. The method for automatically adjusting dose uniformity using multi-pole bar magnet spacing control of claim 1 wherein data acquisition is accomplished using a mobile Faraday bi-directional measurement mode saving about half the time than a uni-directional measurement mode.
4. 4. The method for automatically adjusting dose uniformity using multi-pole bar magnet spacing control of claim 1 wherein the stability of the machine determines the stability and reliability of the method for automatically adjusting dose uniformity during data acquisition.
5. 5. The method for automatically adjusting dose uniformity by utilizing spacing control of magnetic rods with multiple magnetic poles according to claim 1, wherein instantaneous interference of ion beam current or abnormal situation without beam current occurs in the process of data acquisition, wherein the method for automatically adjusting dose uniformity has the advantages of filtering abnormal data in the abnormal situation and ensuring stability of the data and persistence of a program.
6. 6. A method of automatically adjusting dose uniformity using multi-pole bar magnet spacing control as set forth in claim 1, wherein: And analyzing the mathematical model expression, wherein different initial current densities J 0 correspond to different response curves, and replacing a new J 0 in the iterative process to perform iterative calculation, so that the calculation speed of the method for automatically adjusting the dose uniformity is further improved.

Description

Method for automatically adjusting dosage uniformity by utilizing multi-pole magnetic rod spacing control Technical Field The invention relates to the field of semiconductor equipment manufacturing, in particular to a technology for automatically adjusting ion beam dose uniformity by utilizing multi-pole magnetic rod spacing control of an ion implanter. Background With the development of semiconductor integrated circuit manufacturing processes, higher demands are being made on the performance of semiconductor manufacturing equipment. In semiconductor manufacturing equipment, an ion implanter is a doping equipment which is a core in semiconductor device manufacturing and is mainly used for doping treatment for changing the conductivity type and voltage of a target material, and when the wafer size enters the age of 300mm, an advanced device manufacturing process is continuously advanced by 7nm and 5nm, and in order to ensure the uniformity of the device performance on the whole wafer, higher requirements are required for uniformity indexes in the ion implantation doping process. Therefore, it becomes particularly important to achieve automatic adjustment of the dose uniformity of the ion beam current. Based on the above requirements, the invention provides a method for automatically adjusting the dose uniformity by utilizing the multi-pole magnetic rod spacing control, which realizes the automatic adjustment of the dose uniformity of the ion beam. Disclosure of Invention The invention provides a novel method for automatically adjusting the dosage uniformity of multi-pole magnetic rod spacing control in the existing ion implanter technology, which provides reliable and effective support for terminal ion implantation. The invention is realized by the following scheme: Measuring the initial value J0 (1) of ion beam current when the positions of multiple magnetic poles are not changed, respectively increasing or decreasing the distance between the same magnetic rods (short for magnetic rod spacing) by 2n magnetic poles, and collecting the ion beam current value corresponding to each magnetic pole . The response beam values of two magnetic poles which are not interfered with each other can be acquired at one time, so that the moving Faraday movement times are reduced. In order to further improve the data acquisition efficiency, the traditional motion mode of the mobile Faraday is changed from the original unidirectional measurement mode to the bidirectional measurement mode, and about half of time is saved on the original basis. In the process of collecting data, abnormal conditions such as sudden interruption or no beam current and the like may occur, the algorithm filters the abnormal data to ensure the stability of the data and the persistence of a program (2), calculates the amplitude relation between the response of magnetic poles and the spacing of magnetic bars according to the collected data, and assumes that the spacing of the magnetic bars is set to be increased by delta d, and the mathematical model expression is as follows: ; Wherein the method comprises the steps of AndThe response current density difference and the current density when the j-th magnetic pole is set to delta d are shown, respectively. ai. xi and wi are response mathematical model coefficients of the ith magnetic pole, and can be obtained by using a fitting algorithm. Analyzing mathematical model formula, wherein different initial current density J0 corresponds to different response curves, and new J0 can be replaced in the iterative process to perform iterative calculation, so that the calculation speed (3) of the algorithm is further improved, and the least square method is utilized to calculate the average value of each initial beam currentSolving an overdetermined equation, calculating an optimal bar magnet spacing value (4) of each magnetic pole, reading a calculation result by a machine, outputting a beam value, and verifying a debugging effect (5). Three adjusting modes, namely a multi-magnetic pole upper adjusting mode, a multi-magnetic pole lower adjusting mode and a multi-magnetic pole full adjusting mode, are designed, and the optimal adjusting mode is selected according to the current beam state to perform dose uniformity adjustment. The invention has the following remarkable advantages: 1) The data is collected by using a mobile Faraday bidirectional measurement mode, so that about half of time is saved compared with a unidirectional mode; 2) By collecting 2 magnetic pole response data simultaneously and performing iterative calculation, the adjusting efficiency is greatly improved on the basis of ensuring the calculating precision; 3) According to the current beam state, the invention automatically selects the adjusting method, has wide application range and large adjusting force, and can quickly complete target adjustment by embedding the C language program into the machine; Drawings To facilitate a more complete unders