CN207232257U - A kind of alternating temperature four-point probe measurment system - Google Patents

Abstract

The utility model discloses a temperature-variable four-probe measurement system. The vacuum chamber is built with a "匸"-shaped four-probe support, and the bottom of the four-probe support is provided with a heating platform. The temperature controller outside the chamber is connected, and the top of the four-probe bracket is provided with a high-temperature-resistant probe that can be lifted, and the high-temperature-resistant probe is connected with the four-probe tester outside the vacuum chamber, and the vacuum chamber is respectively connected to the vacuum pump, The gas path of the inert gas bottle is connected. The temperature-variable four-probe measuring system of the utility model has the characteristics of good accuracy, wide temperature range, high reliability and simple structure.

Description

A temperature-variable four-probe measurement system

technical field

The utility model relates to the technical field of four-probe testing devices, in particular to a temperature-variable four-probe measuring system.

Background technique

Since Thomson first proposed the four-probe test principle in 1861 and Valdes used it for the semiconductor resistivity test in 1954, due to the simple principle of the four-probe technology, it can eliminate the influence of contact resistance and has high test accuracy. Needle technology has become one of the most widely used process monitoring methods in the semiconductor production process. It is widely used in testing items such as silicon substrates, epitaxial wafers, diffusion sheets, ion implantation sheets, gettering sheets, metal films and coatings, etc., through the resistance test and based on this, control thin film samples The substrate, epitaxy, diffusion, ion implantation, gettering, annealing and other process quality. As shown in Figure 1, the conventional four-probe method is to press four probes arranged in a straight line on the surface of the sample to be tested vertically with a certain pressure, and pass a current I (mA) between the a and d probes. , A certain voltage V (mV) is generated between the b and c probes. Measure this voltage and calculate the resistivity, sheet resistance, and resistance of the sample according to the corresponding formulas according to the measurement method and the size of the sample.

At present, the four-probe tester has been serially produced as a standard testing tool in the semiconductor industry, and the more common ones on the market are the RTS and RDY series. For example: the RTS-8 digital four-probe tester of Guangzhou Four Probe Technology Co., Ltd. is a multi-purpose comprehensive measuring device using the principle of four-probe measurement. It is a special instrument specially designed for testing the resistivity and sheet resistance (sheet resistance) of semiconductor materials, but this system can only be used at room temperature, and cannot test the data changes of samples under heating conditions. Professor Xu Xiaofeng from Donghua University designed a temperature-adjustable four-probe sheet resistance test method, which can measure the sheet resistance at room temperature, and can quickly and accurately measure the sheet resistance at any temperature between room temperature and 120°C , can also quickly analyze the phase transition properties of some functional materials with temperature changes, but the heating rate of this system is difficult to control, and the sheet resistance greater than 120 ° C cannot be measured, and there is no inert gas protection when the temperature is too high, it is easy to damage the sample problem etc.

At the same time, the Chinese utility model patent CN 204925182U is a high-temperature four-probe measurement system, which includes a vacuum atmosphere furnace, a four-probe fixture module, an electric lifting module, a vacuum pump, a controller, a temperature controller, a probe lead, and a test instrument And a PC; wherein, the four-probe fixture module can be inserted into the vacuum atmosphere furnace; the electric lifting module is connected and drives the four-probe fixture module to lift; the vacuum pump is connected with the vacuum atmosphere furnace, and can put the vacuum atmosphere furnace Vacuumize; one end of the controller is connected to a vacuum pump, and the other end is connected to a PC; one end of the temperature controller extends into a vacuum atmosphere furnace, and the other end is connected to a PC; the probe leads are connected to the four-probe fixture module and the controller; A test lead is connected between the controller and the PC, and a test instrument is installed on the test lead. The high-temperature four-probe measurement system has many advantages such as good sealing, good oxidation resistance, and is suitable for continuous temperature rise tests from room temperature to 600°C. However, in practical applications, the system needs to be installed in a vacuum atmosphere furnace, and its structure is very complicated. The long-term continuous high temperature furnace body will also affect the service life of the probe and the accuracy of the test. With the extension of the use process will be greatly reduced.

In summary, although the four-probe tester has been widely used, the existing four-probe tester can only test the sheet resistance at room temperature and relatively stable temperature. The sheet resistance, resistivity and some thermally induced phase change materials (for example: VO ₂ and GST phase change storage materials) sheet resistance versus temperature curve cannot be tested, which limits its application.

Utility model content

The purpose of the utility model is to provide a temperature-variable four-probe measuring system, which has the characteristics of good accuracy, wide temperature range, high reliability and simple structure.

The utility model can be realized through the following technical solutions:

The utility model discloses a temperature-variable four-probe measuring system, which comprises a vacuum chamber, and a "匸"-shaped four-probe support is built in the vacuum chamber, and a heating platform is arranged at the bottom of the four-probe support. The heating table is connected to the temperature controller outside the vacuum chamber, and the top of the four-probe bracket is provided with a liftable high-temperature probe, and the high-temperature probe is connected to the four-probe tester outside the vacuum chamber. They are respectively connected with the vacuum pump and the gas path of the inert gas bottle. The variable temperature four-probe measurement system protected by inert gas effectively integrates the vacuum system, inert gas protection system, temperature control system and four-probe test system, effectively realizes the functions of variable temperature measurement and nitrogen protection, meets the requirements of variable temperature testing, and ensures test accuracy High; it can effectively test the resistance of the sample from room temperature to 500 ° C continuous temperature rise or 500 ° C to room temperature continuous cooling test, the temperature control temperature range is wide; the temperature control system of the system is not affected by the external environment in the vacuum chamber and can effectively achieve a certain The heating or cooling rate is stable, and the temperature control is stable, and can effectively ensure the service life of the probe and its test sensitivity; by adopting the "匸"-shaped four-probe frame structure in the vacuum chamber, the bottom and upper parts of the four-probe frame are respectively A heating platform and a high temperature resistant probe are set up to effectively simplify the structure of the test system.

Further, the inert gas bottle communicates with the gas path of the vacuum chamber through a flow meter, which can facilitate the flow control of the inert gas, meet the test requirements of different materials, and expand the application range of the test system.

Further, a vacuum gauge is also provided in the vacuum chamber to visually manage the vacuum degree of the vacuum chamber to meet the need for accurate testing.

Further, the four-probe tester is connected with a test computer.

Further, the high temperature resistant probe can be raised and lowered by a three-axis drive mechanism. The three-axis driving mechanism is a structural driving part in the prior art, which does not need additional processing and design, simplifies its manufacturing process, and saves the cost of the test system.

Further, the high temperature resistant probe is a probe made of tungsten carbide, which has a long service life and high temperature resistance, which ensures the accuracy of the test and the service life of the probe.

Further, the inert gas bottle is nitrogen and/or argon, which can be flexibly selected according to actual needs to meet the testing requirements of different materials.

The utility model is a temperature-variable four-probe measuring system, which has the following beneficial effects:

First, the accuracy is good. The variable temperature four-probe measurement system protected by inert gas effectively integrates the vacuum system, the inert gas protection system, the temperature control system and the four-probe test system to effectively realize the functions of variable temperature measurement and nitrogen protection. Variable temperature test requirements, high test accuracy;

Second, the temperature range is wide, which can effectively test the resistance of the sample from room temperature to 500 ℃ continuous temperature rise test or 500 ℃ to room temperature continuous temperature drop test, and the temperature control temperature range is wide;

third. High reliability, the temperature control system of the system can effectively achieve a certain heating or cooling rate in the vacuum chamber without being affected by the external environment, the temperature control adjustment is stable, and can effectively guarantee the service life of the probe and its test sensitivity;

Fourth, the structure is simple. By adopting the "匸"-shaped four-probe frame structure in the vacuum chamber, a heating platform and a high-temperature-resistant probe are respectively installed on the bottom and upper parts of the four-probe frame, which effectively simplifies the structure of the test system.

Description of drawings

Accompanying drawing 1 is the test principle diagram of straight line four-probe method;

Accompanying drawing 2 is the system composition diagram of a kind of temperature-variable four-probe measurement system of the utility model;

Accompanying drawing 3 is the change curve of the resistivity of GeSb phase-change memory material with temperature within the range of 25°C to 320°C;

The marks in the drawings include: 1. Vacuum chamber, 2. Vacuum gauge, 3. Vacuum pump, 4. Flow meter, 5. Inert gas bottle, 6. High temperature resistant probe, 7. Four-probe bracket, 8. Heating platform, 9. Temperature controller, 10. Four-probe tester, 11. Computer.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the utility model, the product of the utility model will be further described in detail below in conjunction with the embodiments and accompanying drawings.

As shown in Figure 2, the utility model can be realized through the following technical solutions:

The utility model discloses a temperature-variable four-probe measurement system, which comprises a vacuum chamber 1. The vacuum chamber 1 is equipped with a "匸"-shaped four-probe support 7, and the bottom of the four-probe support 7 is provided with a heating platform 8, the heating platform 8 is connected to the temperature controller 9 outside the vacuum chamber 1, and the top of the four-probe bracket 7 is provided with a liftable high-temperature-resistant probe 6, and the high-temperature-resistant probe 6 is connected to the outside of the vacuum chamber 1 The four-probe tester 10 is connected, and the vacuum chamber 1 is in gas communication with the vacuum pump 3 and the inert gas bottle 5 respectively. The inert gas bottle 5 is in gas communication with the vacuum chamber 1 through a flow meter 4 . A vacuum gauge 2 is also arranged in the vacuum chamber 1 . The four-probe tester 10 is connected to a test computer 11 . The high-temperature-resistant probe 6 is raised and lowered by a three-axis drive mechanism. The high temperature resistant probe 6 is a probe made of tungsten carbide. The inert gas bottle 5 is nitrogen and/or argon.

Compared with the traditional RTS-type four-probe tester, the test system of the utility model has a four-probe measurement system with variable temperature under the protection of inert gas. ℃ to room temperature continuous cooling test; on the other hand, the vacuum system and inert gas protection system of this system provide an ideal test environment for the sample, preventing the sample from being damaged by moisture and oxygen during the test; in addition, The temperature control system of the system is not affected by the external environment in the vacuum chamber and can effectively achieve a certain heating or cooling rate, avoiding the impact of the sample due to rapid heating and cooling. Therefore, this system directly serves the test of the sheet resistance versus temperature curve of metals, semiconductors, and some thermally induced phase change materials.

In practical application, the test system of the present utility model can be designed according to the national standard of single crystal silicon physical test method and with reference to the American A.S.T.M standard to measure silicon crystal block, wafer resistivity and diffusion layer, epitaxial layer, ITO conductive foil film, Sheet resistance of materials such as conductive rubber. The technical parameters of this system reach:

①Resistance measurement range: resistivity: 0.01～10 ⁷ (Ω/cm); square resistance: 0.1～10 ⁷ (Ω/□);

②Temperature change range: 25℃～500℃; heating rate: 1℃/min～20℃/min, cooling rate: 1℃/min～18℃/min;

③ The maximum relative error of the whole machine measurement (tested with a silicon standard sample: 0.01-180Ω/cm) ≤ ± 4%.

The temperature-variable four-probe measurement system of the utility model is applied in the actual test, and the resistivity of the GeSb phase-change storage material is measured in the range of 25° C. to 320° C. as shown in FIG. 3 . It can be seen from the test curve in Figure 3 that the temperature-variable four-probe measurement system of the utility model has the advantages of simple operation, good oxidation resistance, controllable heating and cooling rates, a wide range of measurable square resistance (resistivity), and is suitable for room temperature to 500 ° C continuous temperature rise test or 500 ° C to room temperature continuous cooling test and many other advantages.

The above are only preferred embodiments of the utility model, and are not intended to limit the utility model in any way; all ordinary technical personnel in this industry can smoothly implement the utility model as shown in the accompanying drawings and above; However, any equivalent change, modification and evolution that can be made by those skilled in the art without departing from the scope of the technical solution of the present utility model by using the technical content disclosed above are all equivalent changes of the present utility model. Embodiment; At the same time, any modification, modification and evolution of any equivalent changes made to the above embodiments according to the substantive technology of the utility model still belong to the protection scope of the technical solution of the utility model.

Claims (7)

1. A temperature-variable four-probe measurement system, including a vacuum chamber (1), characterized in that: the vacuum chamber (1) is built with a "匸"-shaped four-probe bracket (7), and the four-probe The bottom of the support (7) is provided with a heating platform (8), the heating platform (8) is connected to the temperature controller (9) outside the vacuum chamber (1), and the top of the four-probe support (7) is provided with A liftable high temperature resistant probe (6), the high temperature resistant probe (6) is connected to the four-probe tester (10) outside the vacuum chamber (1), the vacuum chamber (1) is respectively connected to the vacuum pump (3), The gas path of the inert gas bottle (5) is connected. 2. The temperature-variable four-probe measurement system according to claim 1, characterized in that: the inert gas bottle (5) communicates with the vacuum chamber (1) through a flow meter (4). 3. The temperature-variable four-probe measuring system according to claim 2, characterized in that: a vacuum gauge (2) is also arranged in the vacuum chamber (1). 4. The temperature-variable four-probe measurement system according to claim 3, characterized in that: the four-probe tester (10) is connected to a test computer (11). 5. The temperature-variable four-probe measuring system according to claim 4, characterized in that: the high-temperature-resistant probe (6) is raised and lowered by a three-axis drive mechanism. 6. The variable temperature four-probe measurement system according to claim 5, characterized in that: the high temperature resistant probe (6) is a probe made of tungsten carbide. 7. The temperature-variable four-probe measurement system according to claim 6, characterized in that: the inert gas bottle (5) is nitrogen and/or argon.