阅读说明：本技术 碲镉汞红外焦平面器件及其制备方法 (HgCdTe infrared focal plane device and its preparing method ) 是由 陈慧卿 胡尚正 吴卿 王成刚 孙浩 于 2019-08-19 设计创作，主要内容包括：本发明公开了一种碲镉汞红外焦平面器件及其制备方法,所述方法包括：将砷离子从掺铟碲镉汞外延层的部分待处理表面注入掺铟碲镉汞外延层内；将注有砷离子的掺铟碲镉汞外延层放入充有气态汞的加热管内,并对加热管抽真空、加热；在加热后的掺铟碲镉汞外延层的待处理表面依次镀碲化镉膜和第一硫化锌膜；将镀有碲化镉膜和第一硫化锌膜的掺铟碲镉汞外延层放入充有气态汞的加热管内,并对加热管抽真空、加热；去除第一硫化锌膜,在碲化镉膜远离掺铟碲镉汞外延层的表面镀第二硫化锌膜。采用本发明,可以降低碲镉汞红外焦平面器件的暗电流和串联电阻,提高碲镉汞红外焦平面器件的零偏阻抗值,实现碲镉汞红外焦平面器件的低成本、小尺寸、高性能。(The invention discloses a mercury cadmium telluride infrared focal plane device and a preparation method thereof, wherein the method comprises the following steps: injecting arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from the part of the surface to be treated of the indium-doped tellurium-cadmium-mercury epitaxial layer; putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube; sequentially plating a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped epitaxial layer; putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube; and removing the first zinc sulfide film, and plating a second zinc sulfide film on the surface of the cadmium telluride film far away from the indium-doped mercury cadmium telluride epitaxial layer. By adopting the invention, the dark current and the series resistance of the HgCdTe infrared focal plane device can be reduced, the zero bias impedance value of the HgCdTe infrared focal plane device is improved, and the low cost, small size and high performance of the HgCdTe infrared focal plane device are realized.)

1. A preparation method of a mercury cadmium telluride infrared focal plane device is characterized by comprising the following steps:

injecting arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from the part to-be-processed surface of the indium-doped tellurium-cadmium-mercury epitaxial layer;

putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

sequentially plating a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped epitaxial layer;

putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

and removing the first zinc sulfide film, and plating a second zinc sulfide film on the surface of the cadmium telluride film far away from the indium-doped mercury cadmium telluride epitaxial layer.

2. The method of claim 1, wherein the implanting arsenic ions into the indium-cadmium-telluride-mercury-doped epitaxial layer from a portion of a surface to be treated of the indium-cadmium-telluride-mercury-doped epitaxial layer comprises:

coating photoresist on the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer, and carrying out photoetching to form at least one photoetching area;

adopting an ion implantation technology to implant arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from a non-photoetching region of the surface to be processed;

and removing the photoresist on the surface to be processed.

3. The method of claim 2, wherein the method further comprises:

and before the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer is coated with photoresist, forming the indium tellurium cadmium mercury doped epitaxial layer on the tellurium zinc cadmium substrate by adopting a liquid phase epitaxy process.

4. The method of claim 1, wherein the arsenic ions are implanted at an energy a of 360KeV a 500 KeV.

5. The method of claim 1, wherein the arsenic ions are implanted at a density of b, 2e14/cm²≤b≤2e15/cm²。

6. The method of claim 1, wherein the placing the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and the evacuating and heating the heating tube comprises:

putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube;

liquid mercury is put into the heating pipe, and the heating pipe is packaged in a vacuum mode;

continuously heating the heating tube for a first time period at a first temperature;

continuously heating the heating tube for a second time period at a second temperature;

wherein the second temperature is less than the first temperature.

7. The method of claim 1, wherein the cadmium telluride coated film has a thickness of 100 nm or more and 200nm or less;

the thickness of the first zinc sulfide film is greater than or equal to 200 nanometers and less than or equal to 300 nanometers.

8. The method of claim 1, wherein placing the indium-doped tellurium-cadmium-mercury epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and evacuating and heating the heating tube comprises:

putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube;

liquid mercury is put into the heating pipe, and the heating pipe is packaged in a vacuum mode;

continuously heating the heating tube for a third time period at a third temperature;

continuously heating the heating tube at a fourth temperature for a fourth time period;

wherein the fourth temperature is less than the third temperature.

9. The method of claim 1, wherein the method further comprises:

and after plating a second zinc disulfide film on the surface of the cadmium telluride film far away from the indium-doped tellurium-cadmium-mercury epitaxial layer, corroding a contact hole on the second zinc disulfide film by adopting a corrosion process, wherein the contact hole penetrates through the second zinc disulfide film and the cadmium telluride film to communicate the area of the indium-doped tellurium-cadmium-mercury epitaxial layer, which is injected with the arsenic ions.

10. A mercury cadmium telluride infrared focal plane device is characterized by comprising:

doping an indium tellurium cadmium mercury epitaxial layer;

the arsenic-doped tellurium-cadmium-mercury layer is embedded in the indium-doped tellurium-cadmium-mercury epitaxial layer;

a cadmium telluride plating film which is arranged on the surface to be processed of the indium-doped mercury cadmium telluride epitaxial layer in a laminating manner;

the second zinc disulfide film is arranged on the surface, away from the indium-doped tellurium-cadmium-mercury epitaxial layer, of the cadmium telluride plated film in a laminated mode;

and the metal connecting piece penetrates through the second zinc disulfide film and the cadmium telluride plated film and is connected with the arsenic-doped tellurium-cadmium mercury layer.

Technical Field

The invention relates to the technical field of infrared focal plane detection, in particular to a mercury cadmium telluride infrared focal plane device and a preparation method thereof.

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 military and civil fields of early warning detection, information reconnaissance, damage effect evaluation, agriculture and animal husbandry, investigation, development and management of forest resources, meteorological forecast, geothermal distribution, earthquake, volcanic activity, space astronomical detection and the like. Mercury cadmium telluride (Hg1-xCdxTe) is an important infrared detection material, and because the forbidden band width of the material is adjustable, the detection spectral range extends from a short wave band to a very long wave band.

Disclosure of Invention

The embodiment of the invention provides a mercury cadmium telluride infrared focal plane device and a preparation method thereof, which are used for solving the problems of high dark current and low zero offset resistance value of an n-on-p type mercury cadmium telluride infrared focal plane device in the prior art.

On one hand, the embodiment of the invention provides a preparation method of a mercury cadmium telluride infrared focal plane device, which comprises the following steps:

injecting arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from the part to-be-processed surface of the indium-doped tellurium-cadmium-mercury epitaxial layer;

putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

sequentially plating a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped epitaxial layer;

putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

and removing the first zinc sulfide film, and plating a second zinc sulfide film on the surface of the cadmium telluride film far away from the indium-doped mercury cadmium telluride epitaxial layer.

According to some embodiments of the present invention, the implanting arsenic ions into the indium-cadmium-telluride-doped mercury epitaxial layer from a part of the surface to be processed of the indium-cadmium-telluride-doped mercury epitaxial layer includes:

coating photoresist on the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer, and carrying out photoetching to form at least one photoetching area;

adopting an ion implantation technology to implant arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from a non-photoetching region of the surface to be processed;

and removing the photoresist on the surface to be processed.

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

and before the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer is coated with photoresist, forming the indium tellurium cadmium mercury doped epitaxial layer on the tellurium zinc cadmium substrate by adopting a liquid phase epitaxy process.

According to some embodiments of the invention, the implantation energy of the arsenic ions is a, and a is more than or equal to 360KeV and less than or equal to 500 KeV.

According to some embodiments of the invention, the implantation density of the arsenic ions is b, 2e14/cm²≤b≤2e15/cm²。

According to some embodiments of the invention, the placing the indium-doped tellurium-cadmium-mercury epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube comprises:

putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube;

liquid mercury is put into the heating pipe, and the heating pipe is packaged in a vacuum mode;

continuously heating the heating tube for a first time period at a first temperature;

continuously heating the heating tube for a second time period at a second temperature;

wherein the second temperature is less than the first temperature.

According to some embodiments of the invention, the cadmium telluride plating film has a thickness of 100 nm or more and 200nm or less;

the thickness of the first zinc sulfide film is greater than or equal to 200 nanometers and less than or equal to 300 nanometers.

According to some embodiments of the invention, placing the indium-doped tellurium-cadmium-mercury epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube comprises:

putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube;

liquid mercury is put into the heating pipe, and the heating pipe is packaged in a vacuum mode;

continuously heating the heating tube for a third time period at a third temperature;

continuously heating the heating tube at a fourth temperature for a fourth time period;

wherein the fourth temperature is less than the third temperature.

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

and after plating a second zinc disulfide film on the surface of the cadmium telluride film far away from the indium-doped tellurium-cadmium-mercury epitaxial layer, corroding a contact hole on the second zinc disulfide film by adopting a corrosion process, wherein the contact hole penetrates through the second zinc disulfide film and the cadmium telluride film to communicate the area of the indium-doped tellurium-cadmium-mercury epitaxial layer, which is injected with the arsenic ions.

On the other hand, the embodiment of the invention also provides a mercury cadmium telluride infrared focal plane device, which comprises the following components:

doping an indium tellurium cadmium mercury epitaxial layer;

the arsenic-doped tellurium-cadmium-mercury layer is embedded in the indium-doped tellurium-cadmium-mercury epitaxial layer;

a cadmium telluride plating film which is laminated on the surface of the indium tellurium cadmium mercury doped epitaxial layer, which is provided with the arsenic tellurium cadmium mercury doped layer;

the second zinc disulfide film is arranged on the surface, away from the indium-doped tellurium-cadmium-mercury epitaxial layer, of the cadmium telluride plated film in a laminated mode;

and the metal connecting piece penetrates through the second zinc disulfide film and the cadmium telluride plated film and is connected with the arsenic-doped tellurium-cadmium mercury layer.

By adopting the embodiment of the invention, the dark current and the series resistance of the HgCdTe infrared focal plane device can be reduced, the zero bias impedance value of the HgCdTe infrared focal plane device is improved, and the low cost, small size and high performance of the HgCdTe infrared focal plane device are realized.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a flow chart of a method for fabricating a HgCdTe infrared focal plane device in an embodiment of the invention;

FIG. 2 is a flow chart of a method for fabricating a HgCdTe infrared focal plane device in an embodiment of the invention;

FIG. 3 is a HgCdTe infrared focal plane device in an embodiment of the invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

On one hand, an embodiment of the present invention provides a method for manufacturing a mercury cadmium telluride infrared focal plane device, as shown in fig. 1, where the method includes:

s101, injecting arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from the part to-be-processed surface of the indium-doped tellurium-cadmium-mercury epitaxial layer;

the "indium tellurium cadmium mercury doped epitaxial layer" can be understood as indium ions doped in the indium tellurium cadmium mercury material. In addition, it should be noted that arsenic ions are implanted from a part of the surface to be processed of the epitaxial layer doped with indium, cadmium and mercury, so that a part of the region inside the epitaxial layer doped with indium, cadmium and mercury has arsenic ions, and a part of the region is free of arsenic ions. The area with arsenic ions in the indium tellurium cadmium mercury doped epitaxial layer can form a P-type area, and the indium tellurium cadmium mercury doped epitaxial layer without arsenic ions is an N-type area.

S102, putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

it can be understood that the indium-doped tellurium-cadmium-mercury epitaxial layer processed in step S101 needs to be heated in a vacuum environment with mercury. As the arsenic ion As is an amphoteric doping element, the arsenic ion As can be used As shallow donor As_Hg+Placed at Hg position to form N type, and can be used As shallow acceptor As_Te-And placing the mixture in a Te position of tellurium to form a P type. Through the heating process, arsenic ions can be activated, and mercury can interact with the indium-doped mercury cadmium telluride epitaxial layer, so that the electrical property of the indium-doped mercury cadmium telluride epitaxial layer is kept in an N type.

S103, sequentially plating a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped epitaxial layer;

it should be noted that step S103 may be understood as a process of passivation. Therefore, the probability of surface leakage current of the p-on-n type mercury cadmium telluride infrared focal plane device can be effectively reduced.

S104, putting the indium-doped tellurium-cadmium-mercury epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube;

it can be understood that the indium-doped tellurium-cadmium-mercury epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film after the step S103 needs to be heated in a vacuum environment with mercury. Therefore, the interdiffusion between the indium-doped mercury cadmium telluride epitaxial layer and the cadmium telluride film can be realized, the probability of surface leakage current of the p-on-N type mercury cadmium telluride infrared focal plane device can be further reduced, and the mercury and the indium-doped mercury cadmium telluride epitaxial layer can interact with each other, so that the electrical property of the indium-doped mercury cadmium telluride epitaxial layer is kept in an N type.

S105, removing the first zinc sulfide film, and plating a second zinc sulfide film on the surface of the cadmium telluride film far away from the indium-doped mercury cadmium telluride epitaxial layer.

Therefore, mercury doping in the first zinc sulfide film can be avoided.

By adopting the preparation method of the mercury cadmium telluride infrared focal plane device, the p-on-n type mercury cadmium telluride infrared focal plane device can be formed, the carrier concentration of the p-on-n type mercury cadmium telluride infrared focal plane device can be easily controlled within a certain range through indium doping, and the long service life of minority carriers (holes) can be obtained more easily, so that the dark current in the mercury cadmium telluride infrared focal plane device can be reduced, and the zero offset resistance value can be improved. And the majority carriers (electrons) have high mobility, so that the series resistance thereof can be effectively reduced. In addition, the p region is formed by injecting arsenic ions, and the p region and the n-on-p in the related technology are the planar junction technology, so that the compatibility of the existing process line is facilitated, and the preparation of a focal plane device with a larger area array and a smaller distance is facilitated.

In some embodiments of the present invention, the carrier concentration of the indium-doped HgCdTe epitaxial layer (i.e., the indium-doped concentration) is at 10¹⁴-10¹⁵cm^-3Within the range. Experiments prove that the indium doping concentration in the range can ensure that the dark current is smaller.

On the basis of the above-described embodiment, various modified embodiments are further proposed, and it is to be noted herein that, in order to make the description brief, only the differences from the above-described embodiment are described in the various modified embodiments.

According to some embodiments of the present invention, implanting arsenic ions into the indium-cadmium-telluride-mercury-doped epitaxial layer from a part of the surface to be processed of the indium-cadmium-telluride-mercury-doped epitaxial layer includes:

coating photoresist on the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer, and carrying out photoetching to form at least one photoetching area;

adopting an ion implantation technology to implant arsenic ions into the indium-doped tellurium-cadmium-mercury epitaxial layer from a non-photoetching area of the surface to be treated;

and removing the photoresist on the surface to be processed.

Therefore, the implantation area and the implantation amount of arsenic ions can be conveniently controlled.

In some embodiments of the present invention, the method for manufacturing a mercury cadmium telluride infrared focal plane device further comprises:

and before the surface to be processed of the indium tellurium cadmium mercury doped epitaxial layer is coated with photoresist, forming the indium tellurium cadmium mercury doped epitaxial layer on the tellurium zinc cadmium substrate by adopting a liquid phase epitaxy process.

According to some embodiments of the present invention, the implantation energy of the arsenic ions is a, and 360KeV ≦ a ≦ 500 KeV. The implantation energy influences the implantation depth of the arsenic ions, and the implantation energy is controlled within the range, so that the arsenic ions can be ensured to be implanted into the indium-doped tellurium-cadmium-mercury epitaxial layer, and the indium-doped tellurium-cadmium-mercury epitaxial layer can be prevented from being penetrated.

According to some embodiments of the invention, the implantation density of arsenic ions is b, 2e14/cm²≤b≤2e15/cm². The implantation density influences the doping concentration of arsenic ions, and the implantation concentration is controlled within the range, so that a P-type region can be formed in the indium-doped tellurium-cadmium-mercury epitaxial layer.

According to some embodiments of the present invention, the implantation angle of the arsenic ions may be between 5 degrees and 9 degrees, for example, the implantation angle of the arsenic ions may be 7 degrees.

According to some embodiments of the invention, placing the indium-doped tellurium-cadmium-mercury epitaxial layer injected with arsenic ions into a heating tube filled with gaseous mercury, vacuumizing and heating the heating tube, and the method comprises the following steps:

putting the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions into a heating tube;

putting liquid mercury into the heating pipe, and carrying out vacuum packaging on the heating pipe; it should be noted that during the heating process, the liquid mercury can be evaporated to form gaseous mercury, which is filled around the indium-doped mercury cadmium telluride epitaxial layer.

Continuously heating the heating pipe at a first temperature for a first time period;

continuously heating the heating pipe at a second temperature for a second time period;

wherein the second temperature is less than the first temperature.

Therefore, the high-temperature annealing can complete the electrical activation of arsenic ions and eliminate the crystal lattice damage, and the low-temperature annealing can fill mercury vacancies to recover the electrical property of the indium-doped tellurium-cadmium-mercury epitaxy into an N type.

In some examples of the invention, the first temperature may range from 370 degrees celsius to 430 degrees celsius. The second temperature may range from 230 degrees celsius to 270 degrees celsius. For example, the first temperature may be 400 degrees celsius and the second temperature may be 250 degrees celsius.

Further, the first time period may be less than the second time period. In some examples of the invention, the first time period may range from 0.5 hours to 1.5 hours, and the second time period may range from 65 hours to 80 hours. For example, the first time period may be 1 hour and the second time period may be 72 hours.

In some embodiments of the invention, the heating tube may be a quartz tube. The heating pipe can be horizontally placed in an annealing furnace for high-low temperature annealing treatment.

In some embodiments of the invention, a magnetron sputtering process is adopted to sequentially plate a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped epitaxial layer.

According to some embodiments of the invention, the cadmium telluride plated film has a thickness of 100 nm or more and 200nm or less;

the thickness of the first zinc sulfide film is not less than 200nm and not more than 300 nm.

According to some embodiments of the invention, placing the indium-doped tellurium-cadmium-mercury epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube filled with gaseous mercury, and vacuumizing and heating the heating tube comprises:

putting the indium tellurium cadmium mercury doped epitaxial layer plated with the cadmium telluride film and the first zinc sulfide film into a heating tube;

putting liquid mercury into the heating pipe, and carrying out vacuum packaging on the heating pipe;

continuously heating the heating pipe at a third temperature for a third time period;

continuously heating the heating pipe at a fourth temperature for a fourth time period;

wherein the fourth temperature is less than the third temperature.

Therefore, interdiffusion between the indium-doped mercury cadmium telluride epitaxial layer and the cadmium telluride film can be completed through high-temperature annealing, the probability of surface leakage current of the p-on-N type mercury cadmium telluride infrared focal plane device can be further reduced, and mercury vacancies can be filled through low-temperature annealing to restore the electrical property of the indium-doped mercury cadmium telluride epitaxial layer to an N type.

In some examples of the invention, the first temperature may range from 270 degrees celsius to 330 degrees celsius. The second temperature may range from 230 degrees celsius to 270 degrees celsius. For example, the first temperature may be 300 degrees celsius and the second temperature may be 250 degrees celsius.

Further, the first time period may be less than the second time period. In some examples of the invention, the first time period may range from 4 hours to 6 hours, and the second time period may range from 65 hours to 80 hours. For example, the first time period may be 5 hours and the second time period may be 72 hours.

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

and after plating a second zinc disulfide film on the surface of the cadmium telluride film far away from the indium-doped tellurium-cadmium-mercury epitaxial layer, corroding a contact hole on the second zinc disulfide film by adopting a corrosion process, wherein the contact hole penetrates through the second zinc disulfide film and the cadmium telluride film to communicate the region of the indium-doped tellurium-cadmium-mercury epitaxial layer injected with arsenic ions.

For example, a contact hole pattern can be formed on the outer surface of the second zinc disulfide film by photoetching technology, an ultrasonic-assisted wet etching process is adopted, and a proper etching solution is selected to etch the second zinc disulfide film and the cadmium telluride film, so that the contact hole penetrates through the second zinc disulfide film and the cadmium telluride film to communicate the region of the indium-doped mercury cadmium telluride epitaxial layer injected with arsenic ions.

Furthermore, one end of the metal connecting piece penetrates through the contact hole and is connected with the area of the indium tellurium cadmium mercury doped epitaxial layer injected with arsenic ions. The metal connecting piece can be a chromium piece, a gold piece, a platinum piece or the like.

The method for manufacturing the mercury cadmium telluride infrared focal plane device according to the embodiment of the invention is described in detail with reference to fig. 2. It is to be understood that the following description is illustrative only and is not intended to be in any way limiting. All similar structures and similar variations thereof adopted by the invention are intended to fall within the scope of the invention.

As shown in fig. 2, the method for manufacturing a mercury cadmium telluride infrared focal plane device according to the embodiment of the invention includes:

s201, forming an indium-doped tellurium-cadmium-mercury N-type epitaxial layer on a tellurium-zinc-cadmium substrate by adopting a liquid phase epitaxy process.

It should be noted that the carrier concentration of the N-type epitaxial layer doped with indium tellurium cadmium mercury needs to be controlled at 10¹⁴-10¹⁵cm^-3Within the range.

S202, coating photoresist on the surface to be processed of the indium tellurium cadmium mercury N type epitaxial layer, and carrying out photoetching to form at least one photoetching area.

S203, adopting the implantation energy of 360KeV and the implantation dosage of 2e14/cm²And the ion implantation process with the implantation angle of 7 degrees injects arsenic ions into the indium tellurium cadmium mercury N-type epitaxial layer from the non-photoetching area of the surface to be processed.

And S204, removing the photoresist on the surface to be processed.

S205, the indium-doped tellurium-cadmium-mercury N-type epitaxial layer injected with the arsenic ions is placed into a quartz tube, liquid mercury is placed into the quartz tube, and then the quartz tube is packaged in vacuum.

It should be noted that, because the indium-doped tellurium-cadmium-mercury N-type epitaxial layer and the tellurium-zinc-cadmium substrate are connected together, the reference to "placing the indium-doped tellurium-cadmium-mercury epitaxial layer injected with arsenic ions into the quartz tube" herein can be understood as placing the indium-doped tellurium-cadmium-mercury N-type epitaxial layer and the tellurium-zinc-cadmium substrate integrally into the quartz tube.

S206, horizontally placing the quartz tube into an annealing furnace, heating at the high temperature of 400 ℃ for 1 hour, and then heating at the low temperature of 250 ℃ for 72 hours.

And S207, sequentially plating a cadmium telluride film and a first zinc sulfide film on the surface to be treated of the heated indium tellurium cadmium mercury doped N-type epitaxial layer by adopting a magnetron sputtering process.

Wherein, the thickness of the cadmium telluride plating film can be 200nm, and the thickness of the first zinc sulfide film can be 200 nm.

S208, putting the indium tellurium cadmium mercury doped N-type epitaxial layer into the quartz tube again, putting liquid mercury into the quartz tube, and then carrying out vacuum packaging on the quartz tube.

S209, horizontally placing the quartz tube into an annealing furnace, heating the quartz tube for 5 hours at a high temperature of 300 ℃, and then heating the quartz tube for 72 hours at a low temperature of 250 ℃.

S210, removing the first zinc sulfide film by hydrochloric acid, and plating a second zinc sulfide film on the outer surface of the cadmium telluride film.

The second zinc sulfide film is the same as the first zinc sulfide film.

And S211, forming a contact hole penetrating through the second zinc disulfide film and the cadmium telluride film by adopting a corrosion process so as to communicate the outside with the P-type region injected with arsenic ions by the indium-doped tellurium-cadmium-mercury N-type epitaxial layer.

S212, one end of the metal connecting piece penetrates through the contact hole and is connected with the P-type region, wherein the arsenic ions are injected into the N-type epitaxial layer of the indium tellurium cadmium mercury.

The metal connecting piece can be a chromium piece, a gold piece, a platinum piece or the like.

By adopting the embodiment of the invention, the p-on-n type mercury cadmium telluride infrared focal plane device can be formed, the dark current in the mercury cadmium telluride infrared focal plane device can be obviously reduced, the working temperature of the mercury cadmium telluride infrared focal plane device can be provided, and the mercury cadmium telluride infrared focal plane device can be conveniently and easily realized and compatible with the conventional n-on-p process platform, so that the manufacturing cost can be effectively controlled.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention, and those skilled in the art can make various modifications and changes. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

On the other hand, an embodiment of the present invention further provides a mercury cadmium telluride infrared focal plane device 1, as shown in fig. 3, where the mercury cadmium telluride infrared focal plane device 1 includes: the epitaxial layer 10 doped with indium tellurium cadmium mercury, the layer 20 doped with arsenic tellurium cadmium mercury, the cadmium telluride plated film 30, the second zinc disulfide film 40 and the metal connecting piece 50.

Wherein, the arsenic tellurium cadmium mercury layer 20 is embedded in the indium tellurium cadmium mercury epitaxial layer 10. The cadmium telluride plating film 30 is arranged on the surface to be processed of the indium tellurium cadmium mercury doping epitaxial layer 10 in a laminating way. The surface to be processed is the surface of the indium-doped tellurium-cadmium-mercury epitaxial layer 10 which is used for embedding one side of the arsenic-doped tellurium-cadmium-mercury layer 20. The second zinc disulfide film 40 is arranged on the surface of the cadmium telluride plating film 30 far away from the indium tellurium cadmium mercury doping epitaxial layer 10 in a laminating mode. The metal connecting piece 50 sequentially penetrates through the second zinc disulfide film 40 and the cadmium telluride plated film 30 and is connected with the arsenic-doped cadmium telluride mercury layer 20.

By adopting the embodiment of the invention, the dark current and the series resistance of the HgCdTe infrared focal plane device can be reduced, the zero bias impedance value of the HgCdTe infrared focal plane device is improved, and the low cost, small size and high performance of the HgCdTe infrared focal plane device are realized.

It should be noted that in the description of the present specification, reference to the description of the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.