阅读说明：本技术 一种偏振红外探测器的制备方法 (Preparation method of polarized infrared detector ) 是由 张轶 刘世光 林国画 于 2021-07-21 设计创作，主要内容包括：本发明提出了一种偏振红外探测器的制备方法,包括：S100,在硅片上依次生长隔离层和偏振金属层；S200,通过光刻工艺在偏振金属层生成光刻结构层；S300,基于光刻结构层对偏振金属层进行刻蚀,直至未被光刻结构层覆盖的部分漏出隔离层；S400,去除光刻结构层,完成金属偏振光栅制备；S500,将完成金属偏振光栅制备的硅片与红外探测器的碲镉汞表面连接；S600,去除硅片和隔离层,完成偏振红外探测器的制备。本发明的制备方法,通过预先在硅片上制备偏振光栅,避免了偏振光栅制备过程中损伤红外探测器,而影响红外探测器性能的问题。而且,硅片表面平整度高,偏振光栅制备工艺简单,可以用于制备高消光比的偏振长波碲镉汞探测器。(The invention provides a preparation method of a polarized infrared detector, which comprises the following steps: s100, growing an isolation layer and a polarization metal layer on a silicon wafer in sequence; s200, generating a photoetching structure layer on the polarization metal layer through a photoetching process; s300, etching the polarization metal layer based on the photoetching structural layer until the part uncovered by the photoetching structural layer leaks out of the isolation layer; s400, removing the photoetching structure layer to complete the preparation of the metal polarization grating; s500, connecting the silicon wafer with the metal polarization grating and the mercury cadmium telluride surface of the infrared detector; s600, removing the silicon wafer and the isolating layer to finish the preparation of the polarization infrared detector. According to the preparation method, the polarization grating is prepared on the silicon wafer in advance, so that the problem that the infrared detector is damaged in the preparation process of the polarization grating to influence the performance of the infrared detector is solved. Moreover, the surface flatness of the silicon wafer is high, the preparation process of the polarization grating is simple, and the polarization long-wave tellurium-cadmium-mercury detector with high extinction ratio can be prepared.)

1. A method for manufacturing a polarized infrared detector is characterized by comprising the following steps:

s100, growing an isolation layer and a polarization metal layer on a silicon wafer in sequence;

s200, generating a photoetching structure layer on the polarization metal layer through a photoetching process;

s300, etching the polarization metal layer based on the photoetching structural layer until the part uncovered by the photoetching structural layer leaks out of the isolation layer;

s400, removing the photoetching structure layer to finish the preparation of the metal polarization grating;

s500, connecting the silicon wafer with the metal polarization grating and the mercury cadmium telluride surface of the infrared detector;

s600, removing the silicon wafer and the isolation layer to finish the preparation of the polarized infrared detector.

2. The method of claim 1, wherein the photoresist structure layer is a photoresist with a predetermined pattern formed on the polarization metal layer by a photolithography process.

3. The method of claim 1, wherein in step S300, an ion etching device is used to etch the polarization metal layer not covered by the photolithography structure layer.

4. The method for preparing a polarized infrared detector according to claim 1, wherein before the S500, the method further comprises:

and covering and protecting the leading-out structure of the reading circuit of the infrared detector by using an adhesive tape.

5. The method for preparing a polarized infrared detector according to claim 1, wherein before the S500, the method further comprises:

and arranging alignment marks on the surfaces of the silicon chip and the infrared detector reading circuit.

6. The method for manufacturing a polarized infrared detector as claimed in claim 5, wherein the S500 comprises:

s510, uniformly coating glue on the infrared detector in a rotary gluing mode;

and S520, connecting the silicon wafer prepared by the metal polarization grating and the mercury cadmium telluride surface of the infrared detector by adopting flip interconnection equipment based on the silicon wafer and the alignment marks on the reading circuit.

7. A method of making a polarized infrared detector as claimed in claim 1, wherein the spacer layer is a gold spacer layer.

8. The method for manufacturing a polarized infrared detector as claimed in claim 7, wherein in the step S600, the connected silicon wafer and the infrared detector are put together in an ultrasonic bath to separate the gold isolation layer from the silicon wafer, and then the gold isolation layer on the surface of the infrared detector is removed by using an etching solution.

9. The method of claim 8, wherein the ultrasonic power in the ultrasonic bath is in the range of 18W-22W.

10. A method for preparing a polarized infrared detector according to any one of claims 1 to 9, characterized in that the method is used for preparing a long-wave mercury cadmium telluride polarization detector.

Technical Field

The invention relates to the technical field of microelectronic processes, in particular to a preparation method of a polarized infrared detector.

Background

The infrared focal plane detection technology has the remarkable advantages of wide spectral response wave band, capability of obtaining more ground target information, capability of working day and night and the like, and is widely applied to the fields of agriculture and animal husbandry, investigation, development and management of forest resources, meteorological forecast, geothermal distribution, earthquake, volcanic activity, space astronomical detection and the like. The long-wave infrared detector of mercury cadmium telluride is one of the representative products of infrared detection technology, and is the development direction of the new-generation infrared detector.

The long-wave infrared detector of mercury cadmium telluride is one of the representative products of the infrared detection technology, and in order to realize the detection of long-wave infrared polarized light, a polarization grating (as shown in fig. 1) needs to be processed on the long-wave mercury cadmium telluride detector at the position corresponding to the pixel. Because the long-wave HgCdTe material is extremely sensitive and has fragile physical properties, the performance of the long-wave HgCdTe detector is easily degraded in the preparation process of the polarization grating, and the polarization grating is extremely difficult to process on the surface of the long-wave HgCdTe detector.

Disclosure of Invention

The invention provides a method for manufacturing a polarized infrared detector, which aims to solve the technical problem of how to manufacture the polarized infrared detector.

The preparation method of the polarized infrared detector comprises the following steps:

s100, growing an isolation layer and a polarization metal layer on a silicon wafer in sequence;

s200, generating a photoetching structure layer on the polarization metal layer through a photoetching process;

s300, etching the polarization metal layer based on the photoetching structural layer until the part uncovered by the photoetching structural layer leaks out of the isolation layer;

s400, removing the photoetching structure layer to finish the preparation of the metal polarization grating;

s500, connecting the silicon wafer with the metal polarization grating and the mercury cadmium telluride surface of the infrared detector;

s600, removing the silicon wafer and the isolation layer to finish the preparation of the polarized infrared detector.

According to the preparation method of the polarization infrared detector, the polarization grating is prepared on the silicon wafer in advance, so that the problem that the infrared detector is damaged in the preparation process of the polarization grating to influence the performance of the infrared detector is solved. Moreover, the surface smoothness of the silicon wafer is high, the preparation process of the polarization grating is simple, the design goodness of fit of the prepared polarization grating is high, and the polarization grating can be used for preparing a polarization long-wave tellurium-cadmium-mercury detector with a high extinction ratio.

According to some embodiments of the present invention, the photolithography structure layer is a photoresist with a predetermined pattern generated on the polarization metal layer by a photolithography process.

In some embodiments of the present invention, in S300, an ion etching apparatus is used to etch the polarization metal layer that is not covered by the photolithography structure layer.

According to some embodiments of the invention, prior to the S500, the method further comprises:

and covering and protecting the leading-out structure of the reading circuit of the infrared detector by using an adhesive tape.

In some embodiments of the invention, before the S500, the method further comprises:

and arranging alignment marks on the surfaces of the silicon chip and the infrared detector reading circuit.

According to some embodiments of the invention, the S500 comprises:

s510, uniformly coating glue on the infrared detector in a rotary gluing mode;

and S520, connecting the silicon wafer prepared by the metal polarization grating and the mercury cadmium telluride surface of the infrared detector by adopting flip interconnection equipment based on the silicon wafer and the alignment marks on the reading circuit.

In some embodiments of the invention, the isolation layer is a gold isolation layer.

According to some embodiments of the present invention, in S600, the connected silicon wafer and the infrared detector are put together into an ultrasonic bath to separate the gold isolation layer from the silicon wafer, and then the gold isolation layer on the surface of the infrared detector is removed with an etching solution.

In some embodiments of the invention, the ultrasonic power in the ultrasonic bath ranges from 18W to 22W.

According to some embodiments of the invention, the method is used for the preparation of a long-wave mercury cadmium telluride polarization detector.

Drawings

FIG. 1 is a schematic view of a polarization grating of an infrared detector;

FIG. 2 is a flow chart of a method for fabricating a polarized infrared detector according to an embodiment of the invention;

FIG. 3 is a schematic diagram of an isolation layer and a polarization metal layer grown on a silicon wafer in a manufacturing method according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a polarization grating structure transferred to a surface of a polarization metal layer by a photolithography process in a manufacturing method according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of etching a polarization structure of a polarization metal layer according to photolithography shift by using an ion etching apparatus in a manufacturing method according to an embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating a process of etching a polarization metal layer uncovered by a photoresist to remove the polarization metal layer and expose an isolation layer;

FIG. 7 is a schematic diagram illustrating a metal polarization grating after removing the photoresist according to an embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating glue being uniformly applied on an infrared detector by means of spin coating in the manufacturing method according to the embodiment of the invention;

FIG. 9 is a schematic diagram of a flip-chip interconnection device used in the manufacturing method according to the embodiment of the present invention to align alignment marks on a silicon wafer with alignment marks on a readout circuit of an infrared detector, and then interconnect the alignment marks and take out the alignment marks after glue is cured;

FIG. 10 is a schematic diagram illustrating the long-wave HgCdTe polarization detector manufactured by removing the silicon wafer and the isolation layer in the manufacturing method according to the embodiment of the invention.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the intended purpose, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

The description of the method flow in the present specification and the steps of the flow chart in the drawings of the present specification are not necessarily strictly performed by the step numbers, and the execution order of the method steps may be changed. Moreover, certain steps may be omitted, multiple steps may be combined into one step execution, and/or a step may be broken down into multiple step executions.

As shown in fig. 2, a method for manufacturing a polarized infrared detector according to an embodiment of the present invention includes:

s100, as shown in figure 3, growing an isolation layer and a polarization metal layer on a silicon wafer in sequence;

s200, as shown in FIG. 4, generating a photoetching structure layer on the polarization metal layer through a photoetching process;

s300, as shown in FIGS. 5-6, etching the polarization metal layer based on the photoetching structure layer until the part uncovered by the photoetching structure layer leaks out of the isolation layer;

s400, as shown in FIG. 7, removing the photoetching structure layer to complete the preparation of the metal polarization grating;

s500, as shown in FIG. 9, connecting the silicon wafer with the metal polarization grating prepared and the mercury cadmium telluride surface of the infrared detector;

s600, as shown in FIG. 10, the silicon wafer and the isolation layer are removed, and the preparation of the polarized infrared detector is completed.

According to the preparation method of the polarization infrared detector, the polarization grating is prepared on the silicon wafer in advance, so that the problem that the infrared detector is damaged in the preparation process of the polarization grating to influence the performance of the infrared detector is solved. Moreover, the surface smoothness of the silicon wafer is high, the preparation process of the polarization grating is simple, the design goodness of fit of the prepared polarization grating is high, and the polarization grating can be used for preparing a polarization long-wave tellurium-cadmium-mercury detector with a high extinction ratio.

According to some embodiments of the present invention, the photolithography structure layer is a photoresist with a predetermined pattern generated on the polarization metal layer by photolithography process.

In some embodiments of the present invention, in S300, the ion etching apparatus is used to etch the polarization metal layer that is not covered by the photolithography structure layer.

According to some embodiments of the invention, prior to S500, the method further comprises:

and covering and protecting the leading-out structure of the reading circuit of the infrared detector by using an adhesive tape.

In some embodiments of the invention, prior to S500, the method further comprises:

and arranging alignment marks on the surfaces of the silicon chip and the infrared detector reading circuit.

According to some embodiments of the invention, S500 comprises:

s510, as shown in FIG. 8, uniformly coating glue on the infrared detector in a rotary glue coating mode;

and S520, connecting the silicon wafer prepared by the metal polarization grating and the tellurium-cadmium-mercury surface of the infrared detector by using flip interconnection equipment based on the alignment marks on the silicon wafer and the reading circuit.

In some embodiments of the invention, the isolation layer is a gold isolation layer.

According to some embodiments of the present invention, in S600, the connected silicon wafer and the infrared detector are put together in an ultrasonic bath to separate the gold isolation layer from the silicon wafer, and then the gold isolation layer on the surface of the infrared detector is removed with an etching solution. Wherein the ultrasonic power range in the ultrasonic pool is 18W-22W.

According to some embodiments of the invention, the method can be used for preparing the long-wave tellurium-cadmium-mercury polarization detector.

The method for manufacturing a polarized infrared detector according to the present invention will be described in detail in one specific embodiment with reference to the accompanying drawings. It is to be understood that the following description is only exemplary in nature and should not be taken as a specific limitation on the invention.

The invention provides a preparation method of a polarization infrared detector, which can be used for preparing a long-wave tellurium-cadmium-mercury polarization detector and comprises the following steps: firstly preparing a grating structure and an alignment mark corresponding to a reading circuit of a long-wave tellurium-cadmium-mercury detector on the surface of a silicon wafer polished on a single side, then coating glue on the surface of the long-wave tellurium-cadmium-mercury detector after protecting electricity by using an adhesive tape and leading out, then aligning the long-wave tellurium-cadmium-mercury detector and the silicon wafer with the grating structure in a flip interconnection mode, interconnecting and curing the glue, finally taking down the long-wave tellurium-cadmium-mercury detector by slight ultrasound, and removing Au on the surface by etching to complete the preparation of the long-wave tellurium-cadmium-mercury polarization detector, and the method comprises the following specific steps:

the method comprises the following steps: as shown in fig. 3, a polarization metal and Au isolation layer is grown on a silicon wafer;

step two: as shown in fig. 4, the polarization grating structure is transferred to the surface of the metal layer by a photolithography process;

step three: as shown in fig. 5, the polarization metal layer is etched according to the polarization structure of the photolithography shift using an ion etching apparatus;

step four: as shown in fig. 6, the polarization metal not covered by the photoresist is etched and removed, and the etching process is completed after the Au isolation layer is exposed;

step five: as shown in fig. 7, the metal polarization grating is completed after the photoresist is removed;

step six: as shown in fig. 8, glue is uniformly coated on the long-wave tellurium-cadmium-mercury detector in a rotary glue coating manner;

step seven: as shown in fig. 9, a flip interconnection device is used to interconnect the alignment mark on the silicon wafer with the alignment mark on the readout circuit of the long-wave te-cd-hg detector, and then the interconnection is taken out after the glue is cured;

step eight: as shown in FIG. 10, the silicon wafer and the long-wave HgCdTe detector are placed together in an ultrasonic pool, 20W power ultrasound is used for separating the Au isolation layer from the silicon wafer, and then the Au on the surface of the detector is removed by KI/I2 corrosive liquid, so that the preparation of the long-wave HgCdTe polarization detector is completed.

In conclusion, the polarization grating is prepared on the silicon chip, and the damage of the preparation process to the performance of the long-wave tellurium-cadmium-mercury detector is avoided. The preparation process of the silicon wafer surface flatness high polarization grating is simple, and the prepared polarization grating has high design goodness of fit. The polarized long wave tellurium-cadmium-mercury detector with high extinction ratio can be prepared.

While the invention has been described in connection with specific embodiments thereof, it is to be understood that it is intended by the appended drawings and description that the invention may be embodied in other specific forms without departing from the spirit or scope of the invention.