An infrared detector with integrated temperature monitoring structure

Abstract

The present invention discloses an infrared detector with an integrated temperature monitoring structure. The infrared detector is fabricated on one side of an infrared material; a temperature-sensitive unit for temperature monitoring is fabricated on the other side. This temperature-sensitive unit is constructed by growing an insulating dielectric layer and a chromium-platinum metal layer structure on the infrared material, preparing an electrode region, and then measuring the resistance after leading out the two ends of the chromium-platinum metal layer, thereby enabling real-time monitoring of the chip's temperature. The temperature-sensitive unit for temperature monitoring in this patent is fabricated using techniques such as photolithography and coating, resulting in good consistency. This temperature-sensitive unit can adjust the chromium-platinum metal layer structure based on the detector structure, enabling accurate measurement of the infrared detector's temperature.

Description

Technical field:

[0001] The present invention relates to an infrared detector with an integrated temperature monitoring structure. Specifically, during the infrared detector fabrication process, the infrared detector is fabricated on one side of an infrared material; on the other side, a temperature-sensitive unit for temperature monitoring is fabricated using semiconductor fabrication techniques such as photolithography and coating. The real-time temperature of the infrared detector is determined by measuring the resistance of the temperature-sensitive unit. Background technology:

[0002] In the semiconductor industry, many semiconductor components operate within a specific temperature range. Currently, infrared detector temperature measurement typically involves attaching a commercially available platinum resistor (PT100 or PT1000) to the component using glue. To accurately measure the temperature of an infrared detector component, the resistor should be as close to the component as possible, and its position should ideally be consistent with the component. While this method of directly attaching a platinum resistor is convenient, it typically requires a distance (>2mm) from the chip due to the attachment process. Furthermore, the resistor's position differs from that of the semiconductor component being measured. Semiconductors experience a temperature rise during operation, requiring heat conduction over a certain distance to reach the resistor. Therefore, attaching a platinum resistor to the component doesn't accurately measure the semiconductor component's temperature. This is especially true in infrared detector applications, where infrared detectors typically operate at low temperatures. Their performance is significantly affected by temperature. During operation, infrared detectors generate heat, causing a temperature rise. Because the platinum resistor is distant from the detector, measuring the detector's temperature using this method can sometimes be inaccurate. Summary of the invention:

[0003] The infrared detector with an integrated temperature monitoring structure, described in this invention, directly integrates a platinum resistor structure capable of measuring temperature onto the infrared detector. During the infrared detector fabrication process, semiconductor fabrication techniques such as photolithography and coating are utilized to create the temperature-measuring structure. This ensures that the platinum resistor and the infrared detector are in the same state, effectively reflecting the infrared detector's temperature. Furthermore, because this platinum resistor temperature-measuring structure can be adjusted to the infrared detector's shape, it has a wide range of applications.

[0004] The structure of the infrared detector with integrated temperature monitoring structure is:

[0005] On one side of the infrared material layer 2 there is an infrared detector photosensitive element 1, and on the other side there is a temperature sensitive unit composed of an insulating layer 3, a chromium-platinum metal layer 4 and a chromium-gold metal layer 5 in sequence.

[0006] The chromium-platinum metal layer 4 in the temperature sensitive unit is a rectangular structure formed by chromium-platinum metal arranged back and forth, and both ends of the chromium-platinum metal layer 4 are connected to the chromium-gold metal layer 5 to form electrodes connected to the external circuit.

[0007] The chromium-platinum metal layer 4 is prepared by an ion beam sputtering method and has a thickness of 0.3 to 0.6 microns and a width of 10 to 30 microns.

[0008] The infrared material layer 2 is a mercury cadmium telluride layer epitaxially grown on a cadmium zinc telluride substrate.

[0009] The insulating layer 3 is a SiO2 layer with a thickness of 0.3 to 0.5 microns.

[0010] The specific steps of an infrared detector with an integrated temperature monitoring structure in the present invention are as follows:

[0011] 1. After the infrared detector is prepared, the photosensitive part and electrode part of the detector are protected with photoresist using the photolithography method.

[0012] 2. Using photolithography and vacuum coating, grow an insulating dielectric layer outside the infrared detector's photosensitive area and electrode area. This layer serves to insulate the infrared detector. A thin insulating layer will not provide adequate insulation, while a thick layer may affect the film's reliability. A suitable thickness is 0.3 to 0.5 microns, and this thickness can be selected based on process conditions.

[0013] 3. Using photolithography and vacuum coating, a chromium-platinum metal layer, representing the temperature monitoring structure, is grown on the insulating dielectric layer. The chromium layer serves to enhance the reliability of the metal contact; the platinum layer is the temperature monitoring structure in the invention (the detector temperature is measured by measuring the resistance of the platinum layer). The resistance is closely related to the thickness of the platinum layer.

[0014] 4. Use photolithography and vacuum coating to grow two contact electrode areas for the temperature monitoring structure. The two electrode areas are connected to the two ends of the temperature monitoring structure respectively. By leading out the electrodes, the resistance of the temperature monitoring structure can be tested.

[0015] 5. Calibrate the temperature monitoring structure. Lead out the electrode area of ​​the temperature monitoring structure by bonding gold wires. Measure the resistance of the platinum metal layer at different temperatures to obtain a temperature curve of the platinum metal layer's resistance. Then, when the infrared detector is operating, measure the resistance of the platinum metal layer and compare it with the previous resistance-temperature curve to obtain the temperature of the infrared detector. Description of the drawings:

[0016] Figure 1This is a cross-sectional view of an infrared detector with an integrated temperature measurement structure. 1 is the infrared detector, 2 is the infrared material, 3 is the insulating layer, 4 is the chromium-platinum metal layer, and 5 is the chromium-gold metal layer.

[0017] Figure 2 1 is a top view of an infrared detector with an integrated temperature measurement structure according to an embodiment of the present invention.

[0018] Figure 3 1 is a curve showing the change of resistance versus temperature for two different temperature measurement structures in an embodiment of the present invention. Specific embodiment:

[0019] The following is combined with Figure 1 The specific embodiments of the present invention are further described.

[0020] 1) After the semiconductor material is prepared for the infrared detector, it is cleaned and photolithographically processed. An insulating layer 3 is grown in the area other than the infrared photosensitive element 1. The insulating dielectric layer is a SiO2 layer with a thickness of 0.3 microns, which is insulated from the infrared detector.

[0021] 2) A 20 nm thick chromium layer and a 500 nm thick platinum layer 4 are grown on the insulating layer 3 by ion beam sputtering. The width of the platinum metal layer of the temperature measuring structure is 15 μm. The specific structure is shown in the attached diagram. Figure 2 shown.

[0022] Based on the experience of previous preparation, the width of the platinum metal layer is more appropriately between 10 and 30 microns.

[0023] The width of the platinum metal layer is less than 10 microns, and the platinum metal layer is easily affected by the photolithography process. When it exceeds 30 microns, the platinum resistance becomes smaller due to the increase in the width of the platinum metal layer. Under the same temperature change, the change in platinum resistance will become smaller.

[0024] 3) A chromium-gold metal layer 5 is grown on both ends of the chromium-platinum metal layer 4 to form the electrode region of the temperature measurement structure. The chromium layer is 200 nanometers thick, and the gold layer is 2000 nanometers thick. A gold wire is bonded from the electrode region to measure the resistance of the resistor region at different temperatures, revealing the temperature-dependent resistance trend. By measuring the resistance of the platinum resistor, the temperature of the infrared detector can be determined.

[0025] Figure 3 The resistance curves of the temperature-sensing structures on two different infrared detectors manufactured from the same batch show how they change over temperature. While the resistance values ​​of the two structures may differ slightly due to differences in process uniformity, the temperature-dependent resistance trends of the two structures are consistent.

Claims

1. An infrared detector with an integrated temperature monitoring structure, characterized in that: The infrared detector has an infrared detector photosensitive element (1) on one side of an infrared material layer (2), and a temperature sensitive unit composed of an insulating layer (3), a chromium-platinum metal layer (4) and a chromium-gold metal layer (5) in sequence on the other side; The chromium-platinum metal layer (4) in the temperature-sensitive unit is a rectangular structure formed by chromium-platinum metal arranged back and forth, and the two ends of the chromium-platinum metal layer (4) are connected to the chromium-gold metal layer (5) to form electrodes connected to the external circuit; The insulating layer (3) is a SiO2 layer with a thickness of 0.3 to 0.5 microns; The chromium-platinum metal layer (4) is prepared by an ion beam sputtering method and has a thickness of 0.3 to 0.6 microns and a width of 10 to 30 microns; The manufacturing method of the infrared detector with integrated temperature monitoring structure comprises the following steps: A. After the infrared detector is prepared, the photosensitive area and electrode area of ​​the infrared detector are protected by photoresist using the photolithography method; B. Using photolithography and vacuum coating methods, an insulating layer (3) is grown on the portion outside the photosensitive area and electrode area of ​​the infrared detector; C. Using photolithography and vacuum coating methods, a chromium layer and a platinum layer of a temperature monitoring structure are first grown on the insulating layer (3) and then grown to form a chromium-platinum metal layer (4); the chromium layer is used to increase the reliability of the metal contact, and the platinum layer is a temperature monitoring structure; D. Using photolithography and vacuum coating methods, two electrodes consisting of a chromium-gold metal layer (5) of a temperature monitoring structure are grown on both ends of the chromium-platinum metal layer (4). By leading out the electrodes, the resistance of the temperature monitoring structure can be tested; E. Calibrate the temperature monitoring structure; lead out the two electrodes of the temperature monitoring structure by pressing gold wires, measure the resistance of the platinum metal layer at different temperatures, and obtain the temperature change curve of the resistance of the platinum metal layer. Then, when the infrared detector is working, measure the resistance of the platinum metal layer and compare it with the previous resistance-temperature curve to obtain the temperature of the infrared detector.

2. The infrared detector with integrated temperature monitoring structure according to claim 1, characterized in that: The infrared material layer (2) is a mercury cadmium telluride layer epitaxially grown on a cadmium zinc telluride substrate.

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