TWI830547B - Double-layer structure thin film resistor - Google Patents

Abstract

A double-layer structure thin film resistor is provided to solve the problem of the conventional single-layer structure thin film resistor is unstable at high temperature for a long time. The double-layer structure thin film resistor includes a substrate had a carrying surface, a resistive layer located on the carrying surface, and a protective layer located on the other surface of the resistive layer opposite to the carrying surface. The thickness of the resistive layer ranges from 16 to 100 nanometers. The thickness of the protective layer ranges from 16 to 200 nanometers.

Description

Double layer structure thin film resistor

The present invention relates to an electronic component, in particular to a double-layer structure thin film resistor that is stable for a long time and thermally stable.

Sheet Resistance refers to the deposition of resistive materials on wafers with nanometer-level thickness in thin film or semiconductor processes. Because sheet resistors have very high accuracy, they are often used in medical instruments, industrial computers and automobiles. on precision instruments.

Among them, the Temperature Coefficient of Resistance (TCR) refers to the relative change in resistivity when the temperature changes, and is often used as an indicator of the applicability of thin film resistors. However, although the conventional thin film resistors with a single-layer structure have low temperature resistance coefficients, they are , in a high-temperature environment or long-term use, the conventional thin film resistor may overheat and cause the resistance layer in the conventional thin film resistor to undergo temperature rise, oxidation or electrochemical corrosion, causing the resistance layer to be lost and ineffective.

In view of this, there is still a need to improve conventional thin film resistors.

In order to solve the above problems, the purpose of the present invention is to provide a double-layer structure thin film resistor that has higher stability against changes in temperature and time.

The use of the quantifier "a" or "an" in the elements and components described throughout the present invention is only for convenience of use and to provide a common meaning of the scope of the present invention; in the present invention, it should be interpreted as including Including one or at least one, and the single concept also includes the plural case, unless it is obvious that something else is meant.

The double-layer structure thin film resistor of the present invention includes: a base material with a bearing surface; a resistance layer located on the bearing surface, with a thickness of 16 to 100 nanometers; and a protective layer located on the resistor The material of the protective layer is chromium nitride, aluminum nitride, zirconium nitride or niobium nitride, and the thickness of the protective layer is 16 to 60 nanometers.

Accordingly, the double-layer structure thin film resistor of the present invention, with the protective layer located on the surface of the resistance layer, enables the double-layer structure thin film resistor to have higher stability over a long period of time and at high temperatures, and has the ability to prolong the double-layer structure. The effect of the service life of layer thin film resistors.

Wherein, the material of the resistance layer is nickel chromium, nickel chromium silicon, nickel chromium silicon aluminum, nickel chromium silicon yttrium, nickel chromium manganese, nickel chromium yttrium, nickel chromium manganese yttrium or an alloy of nickel chromium manganese yttrium and tantalum. In this way, it has a low temperature resistance coefficient and has the effect of improving the strength of the resistance layer.

The double-layer structure thin film resistor of the present invention also has two electrodes respectively located at both ends of the resistance layer, and each of the electrodes is electrically connected to the resistance layer. In this way, it has the effect of guiding current to act on the resistive layer.

1:Substrate

2:Resistance layer

3: Protective layer

S: Loading surface

E:Electrode

[Figure 1] A side cross-sectional view of the double-layer structure thin film resistor of the present invention.

[Figure 2] Effects of the double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor on the temperature resistance coefficient under different annealing states.

[Figure 3] Effects of the dual-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor on the resistivity under different annealing states.

In order to make the above and other objects, features and advantages of the present invention more obvious and understandable, the following describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings: Please refer to Figure 1, It is a preferred embodiment of the double-layer structure thin film resistor of the present invention, which includes a base material 1, a resistance layer 2 and a protective layer 3. The resistance layer 2 is located on the base material 1, and the protective layer 3 is located on the resistive layer 2.

The substrate 1 has a carrying surface S, which is used to carry various electronic components and circuits through sputtering, such as: DC Magnetron Sputtering and Radio-Frequency. Magnetron Sputtering), or evaporation, laser deposition and other technologies, metal materials can be formed on the base material 1, and the material of the base material 1 can be alumina.

The thickness of the resistive layer 2 can be 16~100 nanometers (nm), preferably 20 nanometers or 40 nanometers or 60 nanometers or 80 nanometers. The resistive layer 2 is located on the carrying surface S. , the material system of the resistance layer 2 can be nickel chromium (NiCr), nickel chromium silicon (NiCrSi), nickel chromium silicon aluminum (NiCrSiAl), nickel chromium silicon yttrium (NiCrSiY), nickel chromium manganese (NiCrMn), nickel chromium yttrium ( NiCrY), nickel-chromium-manganese-yttrium (NiCrMnY), nickel-chromium-manganese-yttrium-tantalum (NiCrMnYTa) and other alloys.

The thickness of the protective layer 3 can be 16~200 nanometers (nm), preferably 20 nanometers or 40 nanometers or 60 nanometers or 80 nanometers or 100 nanometers. The protective layer 3 is located on the On the other surface of the resistance layer 2 relative to the bearing surface S, the protective layer 3 may be made of chromium nitride (CrN), aluminum nitride (AlN), zirconium nitride (ZrN), or niobium nitride (NbN). , silicon nitride (Si ₃ N ₄ ), etc., and the protective layer 3 can inhibit the oxidation of the resistance layer 2 .

The double-layer structure thin film resistor of the present invention can also have two electrodes E. The two electrodes E are respectively located at both ends of the resistance layer 2. The two electrodes E can also be located on the bearing surface S. Each of the electrodes E is electrically connected to the The material of the resistance layer 2 and the two electrodes E may be silver.

The double-layer structure thin film resistor of the present invention can be produced through the following process. A nickel-chromium alloy Ni _0.8 Cr _0.2 with a diameter of 76.2 mm is used as the target material. A vacuum pump (Cryo-pump) is first used to evacuate a vacuum chamber to air pressure. is 7×10 ^-7 Torr, and then use a Mass Flow Controller to introduce pure argon gas into the vacuum chamber. The flow rate of pure argon gas can be 25 cubic centimeters per minute, and then use a DC magnetic Controlled sputtering is performed at a power of 30 Watt and a sputtering speed of 6 nm/min to deposit a nickel-chromium alloy onto the bearing surface S of the substrate 1 to obtain the resistance layer 2 with a thickness of 80 nm. The air pressure during sputtering is 4.5×10 ^-3 Torr.

Then, chromium metal with a diameter of 76.2 mm is used as the target material. First, use a vacuum pump to evacuate the vacuum chamber to an air pressure of 7×10 ^-7 Torr (Torr), and then use a mass flow controller to pump pure argon and pure nitrogen into the target. Introduce into the vacuum chamber, where the flow rate of pure argon can be 25 cubic centimeters per minute, and the flow rate of pure nitrogen can be 15 cubic centimeters per minute, and then use radio frequency magnetron sputtering at a power of 100 watts (Watt) to By depositing chromium nitride onto the upper surface of the resistor layer 2 at a sputtering speed of 2 nm/min, the protective layer 3 with a thickness of 30 nm can be obtained, and the air pressure during sputtering is 5×10 ^-3 Torr (Torr ).

The annealing process refers to heating the metal to a temperature higher than the recrystallization temperature and maintaining it for a period of time before slowly cooling it. In general, the annealing process can restore the properties of the metal that have been reduced by cold working, so it can increase the ductility and toughness of the metal and produce specific effects. microstructure.

Please refer to Figures 2 and 3, which are the change curves of the temperature resistivity and resistivity of the double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor in the unannealed and annealed states. Specifically, the double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor were annealed in a vacuum environment in an unannealed state at temperatures of 200°C and 300°C for 2 hours respectively, and then, using high-resolution An Electron Probe Microanalyzer (EPMA) was used to measure the temperature resistance coefficient (TCR) and resistivity of the dual-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor in different annealing states.

Please refer to Figure 2. In the unannealed state, the temperature resistance coefficient of the double-layer structure thin film resistor of the present invention is -3ppm/℃ and the temperature resistance coefficient of the conventional single-layer structure thin film resistor is 13ppm/℃; After the double-layer structure thin film resistor and the conventional single-layer structure thin film resistor undergo an annealing process, the temperature resistance coefficient of both can increase. However, after the double-layer structure thin film resistor of the present invention undergoes annealing at 200°C, the temperature resistance coefficient increases to 300 ppm/ ℃, and after annealing at 300°C, the temperature resistance coefficient of the double-layer structure thin film resistor of the present invention increases to 428 ppm/°C. From this, it can be seen that the temperature resistance coefficient of the double-layer structure thin film resistor of the present invention after annealing at 200°C is the same as that at 300°C. The difference in the temperature resistance coefficient after annealing is only 128ppm/℃; after the conventional single-layer structure thin film resistor is annealed at 200℃, the temperature resistance coefficient increases to 281ppm/℃, and after annealing at 300℃, the temperature resistance coefficient The increase is 460ppm/℃. It can be seen that the temperature resistance coefficient of the conventional single-layer structure thin film resistor after annealing at 200℃ and the temperature resistance coefficient after annealing at 300℃ has a difference of 179ppm/℃. Therefore, after annealing Under the condition, the temperature resistance coefficient of the double-layer structure thin film resistor of the present invention changes less than the temperature resistance coefficient of the conventional single-layer structure thin film resistor.

Please refer to Figure 3. In the unannealed state, the resistivity of the double-layer structure thin film resistor of the present invention is 471 μΩ-cm. The resistivity of the conventional single-layer structure thin film resistor is 252 μΩ-cm. The difference in resistivity between the two is 219 μΩ. -cm; After the double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor undergo the annealing process, the resistivities of both can decrease. However, the double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor After annealing at 200°C, the resistivity of the double-layer structure thin film resistor of the present invention is 364 μΩ-cm, and the resistivity of the conventional single-layer structure thin film resistor is 238 μΩ-cm. The resistivity difference between the two is 126 μΩ-cm; the double-layer structure thin film resistor of the present invention has a resistivity of 238 μΩ-cm. After annealing at 300°C, the film resistor with a layer structure and the conventional single-layer structure film resistor have a resistivity of 335 μΩ-cm, and the resistivity of the film resistor with a double-layer structure of the present invention is 180 μΩ-cm. The difference in resistivity is up to 155 μΩ-cm. Therefore, in the unannealed and annealed states, the double-layer structure thin film resistor of the present invention has a higher resistivity than the conventional single-layer structure thin film resistor.

Please refer to Table 1. The double-layer structure thin film resistor of the present invention and the conventional single-layer structure thin film resistor were subjected to a thermal test at a temperature of 150°C for 100 hours, and a high-resolution electron microanalyzer (Electron Probe Microanalyzer, EPMA) measures changes in temperature coefficient of resistance (TCR) and resistivity.

As shown in Table 1, the temperature resistance coefficient change rate of the double-layer structure thin film resistor of the present invention is -1.16%, and the temperature resistance coefficient change rate of the conventional single-layer structure thin film resistor is -21.95%. From this, it can be seen that the double-layer structure thin film resistor of the present invention has a temperature resistance coefficient change rate of -1.16%. The temperature resistance coefficient change rate of the layer structure thin film resistor is lower than that of the conventional single layer structure thin film resistor. Therefore, the double layer structure thin film resistor of the present invention has higher stability than the conventional single layer structure thin film resistor in a long-term high temperature environment.

In summary, the double-layer structure thin film resistor of the present invention, with the protective layer located on the surface of the resistive layer, enables the double-layer structure thin film resistor to have higher stability over a long period of time and at high temperature, and therefore can Extend the service life of the double-layer thin film resistor.

Although the present invention has been disclosed using the above-mentioned preferred embodiments, they are not intended to limit the invention. Anyone skilled in the art can make various changes and modifications to the above-described embodiments without departing from the spirit and scope of the invention. The technical scope protected by the invention, therefore, the protection scope of the invention shall include all changes within the literal and equivalent scope described in the appended patent application scope.

1:Substrate

2:Resistance layer

3: Protective layer

S: Loading surface

E:Electrode

Claims (3)

A double-layer structure thin film resistor includes: a base material with a bearing surface; a resistance layer located on the bearing surface, with a thickness of 16 to 100 nanometers; and a protective layer located opposite to the resistance layer On the other surface of the bearing surface, the material of the protective layer is chromium nitride, aluminum nitride, zirconium nitride or niobium nitride, and the thickness of the protective layer is 16~60 nanometers. Such as the double-layer structure thin film resistor of claim 1, wherein the material of the resistance layer is nickel chromium, nickel chromium silicon, nickel chromium silicon aluminum, nickel chromium silicon yttrium, nickel chromium manganese, nickel chromium yttrium, nickel chromium manganese yttrium or nickel Chromium manganese yttrium tantalum alloy. For example, the double-layer structure thin film resistor of claim 1 further has two electrodes respectively located at both ends of the resistance layer, and each of the electrodes is electrically connected to the resistance layer.

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