阅读说明：本技术 一种测量锑化铟材料pn结深度的方法及系统 (Method and system for measuring PN junction depth of indium antimonide material ) 是由 邱国臣 李海燕 于 2019-09-25 设计创作，主要内容包括：本发明提出了一种测量锑化铟材料PN结深度的方法及系统,用以简化锑化铟材料PN深度测量的工艺,降低测量成本。测量锑化铟材料PN结深度的方法,包括：将形成了PN结结构的锑化铟材料浸入腐蚀剂中腐蚀形成腐蚀坡；将腐蚀完成后的锑化铟材料放置于去离子水中清洗、吹干；将吹干后的锑化铟材料放置于阳极氧化装置中进行阳极氧化至所述腐蚀坡表面颜色不同形成两个颜色区；将氧化后的锑化铟材料放置于去离子水中清洗、吹干；根据所述腐蚀坡表面颜色的分界,分别测量腐蚀坡的第一宽度和腐蚀坡坡顶颜色分区的第二宽度；利用台阶仪测量所述腐蚀坡的高度；根据所述第一宽度、第二宽度和所述腐蚀坡的高度,确定所述PN结的深度。(The invention provides a method and a system for measuring the PN junction depth of an indium antimonide material, which are used for simplifying the process of measuring the PN junction depth of the indium antimonide material and reducing the measurement cost. The method for measuring the PN junction depth of the indium antimonide material comprises the following steps: immersing the indium antimonide material with the PN junction structure into a corrosive agent to corrode the indium antimonide material to form a corrosion slope; placing the indium antimonide material after the corrosion is finished in deionized water for cleaning and drying; placing the dried indium antimonide material in an anodic oxidation device for anodic oxidation until the surface of the corrosion slope has different colors to form two color areas; placing the oxidized indium antimonide material in deionized water for cleaning and blow-drying; respectively measuring a first width of the corrosion slope and a second width of the color partition of the top of the corrosion slope according to the color boundary of the surface of the corrosion slope; measuring the height of the corrosion slope by using a step instrument; and determining the depth of the PN junction according to the first width, the second width and the height of the corrosion slope.)

1. A method for measuring the PN junction depth of an indium antimonide material is characterized by comprising the following steps:

immersing the indium antimonide material with the PN junction structure into a corrosive agent to corrode the indium antimonide material to form a corrosion slope;

placing the indium antimonide material after the corrosion is finished in deionized water for cleaning and drying;

placing the dried indium antimonide material in an anodic oxidation device for anodic oxidation until the surface of the corrosion slope has different colors to form two color areas;

placing the oxidized indium antimonide material in deionized water for cleaning and blow-drying;

respectively measuring a first width of the corrosion slope and a second width of the color partition of the top of the corrosion slope according to the color boundary of the surface of the corrosion slope;

measuring the height of the corrosion slope by using a step instrument;

and determining the depth of the PN junction according to the first width, the second width and the height of the corrosion slope.

2. The method of claim 1, wherein before immersing the indium antimonide material with the PN junction structure formed therein in an etchant to etch the indium antimonide material to form an etch slope, the method further comprises:

determining the corrosion time according to the corrosion speed of the corrosion liquid and the estimated depth range of the PN junction;

the indium antimonide material with the PN junction structure is immersed in the corrosive agent to be corroded to form a corrosion slope, and the method specifically comprises the following steps:

and according to the determined corrosion time, immersing the indium antimonide material with the PN junction structure into the corrosive agent for corrosion for a corresponding time to form a corrosion slope.

3. The method according to claim 2, wherein the indium antimonide material with the PN junction structure formed thereon is immersed in an etchant for etching for a corresponding time, and the method specifically comprises the following steps:

placing the indium antimonide material with the PN junction structure on a clamping fixture, wherein the clamping fixture is fixed on a mechanical arm device;

and controlling the clamping fixture to immerse the indium antimonide material into the corrosive at a preset speed for corresponding time by using a mechanical arm.

4. The method of claim 1, wherein the depth of the PN junction is determined based on the first width, the second width, and the height of the erosion slope according to the following equation:

wherein:

x represents the depth of the PN junction;

h represents the height of the corrosion slope;

m first width of the erosion slope;

and n represents a second width of the color zone of the top of the corrosion slope.

5. A system for measuring the depth of a PN junction of an indium antimonide material is characterized by comprising:

the etching device is used for immersing the indium antimonide material with the PN junction structure into the etchant to etch to form an etching slope;

the cleaning and blow-drying device is used for placing the corroded indium antimonide material into deionized water for cleaning and blow-drying; placing the oxidized indium antimonide material in deionized water for cleaning and blow-drying;

the anodic oxidation device is used for placing the indium antimonide material dried by the cleaning and drying device for the first time in the anodic oxidation device for anodic oxidation until the surface color of the corrosion slope is different to form two color areas;

the measuring device is used for respectively measuring the first width of the corrosion slope and the second width of the color partition of the top of the corrosion slope according to the color boundary of the surface of the corrosion slope;

the step instrument is used for measuring the height of the corrosion slope;

and the calculating device is used for determining the depth of the PN junction according to the first width, the second width and the height of the corrosion slope.

6. The system of claim 5,

the etching device is also used for determining the etching time according to the etching speed of the etching solution and the estimated depth range of the PN junction before the indium antimonide material forming the PN junction structure is immersed into the etching agent to be etched to form an etching slope; and according to the determined corrosion time, immersing the indium antimonide material with the PN junction structure into the corrosive agent for corrosion for a corresponding time to form a corrosion slope.

7. The system according to claim 6, wherein the etching device comprises a mechanical arm, a clamping fixture is fixed on the mechanical arm, and the clamping fixture is used for placing the indium antimonide material forming the PN junction structure; and controlling the clamping fixture to immerse the indium antimonide material into the corrosive at a preset speed for corresponding time by using a mechanical arm.

8. The system of claim 6,

the calculating device is specifically configured to determine the depth of the PN junction according to the following formula according to the first width, the second width, and the height of the erosion slope:

wherein:

x represents the depth of the PN junction;

h represents the height of the corrosion slope;

m first width of the erosion slope;

and n represents a second width of the color zone of the top of the corrosion slope.

Technical Field

The invention relates to the technical field of semiconductors, in particular to a method and a system for measuring the PN junction depth of an indium antimonide material.

Background

Indium antimonide material is used as a main stream material for preparing a medium wave infrared detector, a PN junction structure is formed after diffusion, ion implantation or epitaxy process, a detector chip is prepared after post passivation, electrode, flip interconnection and other processes, and a Dewar is packaged into a detector assembly which can be applied to various fields of sea, land and air and used for realizing night vision, tracking and other functions. In the process of the infrared detector, the preparation quality of the PN junction is the core of determining the final performance index of the detector, and the junction depth of the PN junction directly influences the main performance indexes of the detector, such as quantum efficiency, detectivity, responsivity and the like.

Currently, there are two schemes for measuring the junction depth of a PN junction: one can adopt special equipment secondary ion mass spectrometer to test, and the other can adopt angle grinding anodic oxidation method to test. However, the first scheme adopts a secondary ion mass spectrometer for testing, and because the equipment is expensive, only several research units are purchased in China, the PN junction measurement has the problems of high price, long period and inconvenience; and in the second scheme, a corner grinding oxidation mode is adopted for testing, a grinding, polishing and thinning process of a device is involved, the process is complex to realize, a plurality of process operations and the use of various chemical reagents are designed, and the process time is long.

Disclosure of Invention

The invention aims to solve the technical problems of simplifying the process of measuring the PN depth of the indium antimonide material, reducing the measurement cost and providing a method and a system for measuring the PN junction depth of the indium antimonide material.

In a first aspect, an embodiment of the present invention provides a method for measuring a PN junction depth of an indium antimonide material, including:

immersing the indium antimonide material with the PN junction structure into a corrosive agent to corrode the indium antimonide material to form a corrosion slope;

placing the indium antimonide material after the corrosion is finished in deionized water for cleaning and drying;

placing the dried indium antimonide material in an anodic oxidation device for anodic oxidation until the surface of the corrosion slope has different colors to form two color areas;

placing the oxidized indium antimonide material in deionized water for cleaning and blow-drying;

respectively measuring a first width of the corrosion slope and a second width of the color partition of the top of the corrosion slope according to the color boundary of the surface of the corrosion slope;

measuring the height of the corrosion slope by using a step instrument;

and determining the depth of the PN junction according to the first width, the second width and the height of the corrosion slope.

In one embodiment, before immersing the indium antimonide material forming the PN junction structure in an etchant to form an etch slope, the method further includes:

determining the corrosion time according to the corrosion speed of the corrosion liquid and the estimated depth range of the PN junction;

the indium antimonide material with the PN junction structure is immersed in the corrosive agent to be corroded to form a corrosion slope, and the method specifically comprises the following steps:

and according to the determined corrosion time, immersing the indium antimonide material with the PN junction structure into the corrosive agent for corrosion for a corresponding time to form a corrosion slope.

In one embodiment, the method for etching the indium antimonide material with the PN junction structure formed thereon by immersing the indium antimonide material in an etchant for a corresponding time specifically includes:

placing the indium antimonide material with the PN junction structure on a clamping fixture, wherein the clamping fixture is fixed on a mechanical arm device;

and controlling the clamping fixture to immerse the indium antimonide material into the corrosive at a preset speed for corresponding time by using a mechanical arm.

In one embodiment, the depth of the PN junction is determined according to the following equation based on the first width, the second width, and the height of the erosion slope:

wherein:

x represents the depth of the PN junction;

h represents the height of the corrosion slope;

m first width of the erosion slope;

and n represents a second width of the color zone of the top of the corrosion slope.

The invention also provides a system for measuring the PN junction depth of the indium antimonide material, which comprises the following components:

the etching device is used for immersing the indium antimonide material with the PN junction structure into the etchant to etch to form an etching slope;

the cleaning and blow-drying device is used for placing the corroded indium antimonide material into deionized water for cleaning and blow-drying; placing the oxidized indium antimonide material in deionized water for cleaning and blow-drying;

the anodic oxidation device is used for placing the indium antimonide material dried by the cleaning and drying device for the first time in the anodic oxidation device for anodic oxidation until the surface color of the corrosion slope is different to form two color areas;

the measuring device is used for respectively measuring the first width of the corrosion slope and the second width of the color partition of the top of the corrosion slope according to the color boundary of the surface of the corrosion slope;

the step instrument is used for measuring the height of the corrosion slope;

and the calculating device is used for determining the depth of the PN junction according to the first width, the second width and the height of the corrosion slope.

In one embodiment, the etching device is further used for determining the etching time according to the etching speed of the etching solution and the expected depth range of the PN junction before the indium antimonide material forming the PN junction structure is immersed into the etching agent to be etched to form an etching slope; and according to the determined corrosion time, immersing the indium antimonide material with the PN junction structure into the corrosive agent for corrosion for a corresponding time to form a corrosion slope.

In one embodiment, the etching device comprises a mechanical arm, wherein a clamping fixture is fixed on the mechanical arm and used for placing the indium antimonide material forming the PN junction structure; and controlling the clamping fixture to immerse the indium antimonide material into the corrosive at a preset speed for corresponding time by using a mechanical arm.

In one embodiment, the calculating means is specifically configured to determine the depth of the PN junction according to the following formula based on the first width, the second width and the height of the erosion slope:

wherein:

x represents the depth of the PN junction;

h represents the height of the corrosion slope;

m first width of the erosion slope;

and n represents a second width of the color zone of the top of the corrosion slope.

By adopting the technical scheme, the invention at least has the following advantages:

according to the method and the system for measuring the PN junction depth of the indium antimonide material, the surface color of the indium antimonide material with different doping concentrations is different after anodic oxidation, the surface of the indium antimonide material is corroded to a certain depth and a certain gradient, the corroded indium antimonide material is subjected to anodic oxidation to produce an anodic oxide film with a specified thickness, the widths of different color partitions of the oxide film are respectively measured, the height of a corrosion step is measured by using a step profiler, and the depth of a PN junction is determined according to the widths of the different color partitions and the height of the corrosion step.

Drawings

FIG. 1 is a schematic diagram of the testing principle of an embodiment of the present invention;

FIG. 2 is a flowchart of a method for measuring the PN junction depth of an indium antimonide material according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an etching apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an InSb material etching profile in an embodiment of the present 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.

First, some terms related to the embodiments of the present invention are explained to facilitate understanding by those skilled in the art.

PN junction: by adopting different doping processes, a P-type semiconductor (P is a Positive word head, the name is obtained because the hole is positively charged) and an N-type semiconductor (N is a Negative word head, the name is obtained because the electron is negatively charged) are manufactured on the same semiconductor (generally silicon or germanium) substrate through diffusion, and space charge regions called PN junctions are formed at the interfaces of the P-type semiconductor and the N-type semiconductor. PN junctions have unidirectional conductivity and are the material basis for many devices in electronic technology, such as semiconductor diodes, bipolar transistors.

It should be noted that the terms "first", "second", and the like in the description and the claims of the embodiments of the present invention and in the drawings described above are used for distinguishing similar objects and not necessarily for describing a particular order or sequence. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.

Reference herein to "a plurality or a number" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

As shown in fig. 1, which is a schematic diagram illustrating a principle of measuring a PN junction depth of an indium antimonide material according to an embodiment of the present invention, a color of an anodic oxide film may significantly change with a doping concentration of the indium antimonide material.

As shown in fig. 2, which is a schematic view of an implementation flow of a method for measuring a PN junction depth of an indium antimonide material according to an embodiment of the present invention, the method includes the following steps:

and S21, immersing the indium antimonide material with the PN junction structure into the corrosive agent to corrode the indium antimonide material to form a corrosion slope.