CN202886311U

CN202886311U - PH (potential of hydrogen) detection sensor for AlGaN/GaN ions

Info

Publication number: CN202886311U
Application number: CN 201220561612
Authority: CN
Inventors: 张帆
Original assignee: NINGBO CRISTOFOLI MEDICAL APPARATUS AND INSTRUMENTS CO Ltd
Current assignee: NINGBO CRISTOFOLI MEDICAL APPARATUS AND INSTRUMENTS CO Ltd
Priority date: 2012-10-30
Filing date: 2012-10-30
Publication date: 2013-04-17
Anticipated expiration: 2022-10-30

Abstract

The utility model discloses a PH (potential of hydrogen) detection sensor for AlGaN/GaN ions, wherein the structure of the PH detection sensor is as follows: a GaN layer and an AlGaN layer are sequentially coated on an Si substrate from bottom to top; channels are etched in the surface of the AlGaN layer; passivation layers cover the parts which are not etched with channels on the surface of the AlGaN layer; the channels are less than 1 nm in width; the passivation layers are SiN layers and 5-10 nm in thickness; the GaN layer is 3-5 mum in thickness; and the AlGaN layer is 5-10 nm in thickness.

Description

A kind of AlGaN/GaN ion PH detecting sensor

Technical field

The utility model belongs to biomedical instrument device and applied technical field thereof, especially relates to a kind of AlGaN/GaN sensor for detection of the biological fluid pH value.

Background technology

The GaN base material is compared with traditional semiconductor material, has the obvious characteristics such as the shorter and energy gap of bond distance is larger.Short bond distance means large bond energy and little atomic mass, thereby causes large phonon energy, and the very difficult generation of lattice scattering, can form very high thermal conductivity and saturated mobility in macroscopic view like this.Large energy gap is so that breakdown electric field is higher, and avalanche effect is difficult to occur, and simultaneously, has reduced the generation of high temperature intrinsic carrier and leakage current.When AlGaN and GaN formation heterojunction structure, because two kinds of nitride all have very strong spontaneous polarization, and the piezoelectric polarization that exists in the AlGaN layer, be easy at the extremely strong polarization charge of interface formation, and produce up to 10 ¹³/ cm ²Two-dimensional electron gas (2DEG).The two-dimensional electron gas surface density height that this forms than GaAs base material an order of magnitude.Therefore, the GaN base material is widely used in making high temperature, high frequency, large power semiconductor device.

At medical instruments field, it is more to be used for carrying out the instrument that pH value detects, detected such as the galvanometer formula, it measures potential change by glass electrode and contrast electrode consist of primary element in same solution principle, thereby determine the pH value intensity of solution, but the precision of this instrument can only reach 1% usually, and the PH that can not satisfy human body fluid measures requirement.For overcoming the defective of existing pH value detector, must innovate in measuring principle and structure, the highly sensitive accuracy of detection sensor of development of new, to liquid (urine for example, blood etc.) variation of interior ion pH value is differentiated, simultaneously, this analyte sensors need have high sensitivity and can integrated and small sensitivity, can be used for future war miniaturization detection.

Summary of the invention

The utility model is inadequate for the measuring accuracy that overcomes existing body fluid pH value measuring appliance, and the larger defective of using inconvenience of volume proposes a kind of AlGaN/GaN ion PH detecting sensor of utilizing novel semi-conductor high sensitivity characteristics design.

Its technical scheme that realizes above-mentioned utility model purpose is, a kind of AlGaN/GaN ion PH detecting sensor, its structure are to be coated with successively GaN layer and AlGaN layer on the Si substrate on lower, AlGaN layer surface etch has raceway groove, not the AlGaN layer surface coverage passivation layer of etching raceway groove.

The channel width of the sensor is less than 1nm, realizing the stopping of biomacromolecule in the solution, and K simultaneously ⁺, Na ⁺Can be near AlGaN layer surface Deng small ion.

The passivation layer of the sensor is SiN, and its thickness is 5-10nm, and the thickness of GaN layer is 3-5 μ m, and the thickness of AlGaN layer is 5-10nm,

The utility model also relates to a kind of application of AlGaN/GaN ion PH detecting sensor, and it is mainly used in utilizing AlGaN/GaN ion PH detecting sensor to make the detector of the pH value that detects effects of ion, carries out the pH value of human body fluid and measures.

The method for making of above-mentioned AlGaN/GaN ion PH detecting sensor may further comprise the steps: (1) deposits GaN layer, AlGaN layer and SiN passivation layer successively at the Si substrate, and each layer thickness is followed successively by respectively 3-5 μ m, 5-10nm and 5-10nm; (2) after applying photoresist, the SiN passivation layer surface utilize ICP-RIE dry etching method to form raceway groove at the SiN passivated surface by after exposing, developing; (3) make AlGaN/GaN ion PH detecting sensor after removing photoresist, cleaning.

The utility model utilizes the AlGaN/GaN heterojunction to have the piezoelectricity and spontaneous polarization effect, can accumulate the Two-dimensional electron of one deck high concentration at the heterojunction boundary place.This two-dimensional electron gas provides lower communication channel for the conducting of device, thereby the conducting resistance of device is lower.Lower conducting resistance is very responsive to the two-dimensional electron gas at the interface of heterojunction.When the surveyed area of this device had solion absorption, obvious change can appear in the Two-dimensional electron concentration at the heterojunction boundary place of device, device when conducting, variation has just occured in channel resistance, its sensitivity is up to very much one.Utilize human body fluid pH value sensor that this principle makes can be rapidly, the sensitive and accurate measurement of high precision determines the pH value of body fluid, intellectuality, the miniaturization of realization medical treatment device.

Description of drawings

Fig. 1 is the utility model AlGaN/GaN ion PH detecting sensor structural representation;

Fig. 2 is the principle of work of AlGaN/GaN ion PH detecting sensor;

Among the figure, 1, passivation layer; 2, biomacromolecule; 3, raceway groove; 4, AlGaN layer; 5, GaN layer; 6, Si substrate.

Embodiment

Below in conjunction with accompanying drawing the utility model is described further, the utility model AlGaN/GaN ion PH detecting sensor structural representation such as Fig. 1, as shown in the figure, AlGaN/GaN ion PH detecting sensor structure of the present utility model is, on lower, be coated with successively GaN layer 5 and AlGaN layer 4 on the Si substrate 6, AlGaN layer surface etch has raceway groove 3, not the AlGaN layer surface coverage passivation layer 1 of etching raceway groove.

The channel width of the sensor is less than 1nm, realizing the stopping of biomacromolecule in the solution 2, and K simultaneously ⁺, Na ⁺Can be near AlGaN layer surface Deng small ion.

Fig. 2 is the principle of work of AlGaN/GaN ion PH detecting sensor of the present utility model, as shown in the figure, and the Na in solution ⁺, K ⁺, H ⁺Ion, OH ^-When surperficial near the AlGaN of raceway groove inside, interface place at AlGaN and GaN can produce the conducting electric weight, the intensity of its electric current is relevant with the ion concentration in the solution, just can determine ion concentration in the solution, the size of ie in solution pH value by the strength of current of measuring semiconductor AlGaN/GaN.

The method for making step of AlGaN/GaN ion PH detecting sensor of the present utility model is: (1) deposits GaN layer, AlGaN layer and SiN passivation layer successively at the Si substrate, and each layer thickness is followed successively by respectively 3-5 μ m, 5-10nm and 5-10nm; (2) after applying photoresist, the SiN passivation layer surface utilize ICP-RIE dry etching method to form raceway groove at the SiN passivated surface by after exposing, developing; (3) make AlGaN/GaN ion PH detecting sensor after removing photoresist, cleaning.

The above; preferred embodiment for the utility model content; be not that the utility model content is imposed any restrictions; all any simple modification, change and equivalent structures of above embodiment being done according to the utility model content technologies essence change, and all belong in the protection domain of the utility model content technologies scheme.

Claims

1. AlGaN/GaN ion PH detecting sensor, it is characterized in that, be coated with successively GaN layer (5) and AlGaN layer (4) on the Si substrate (6) on lower, AlGaN layer surface etch has raceway groove (3), not the AlGaN layer surface coverage passivation layer (1) of etching raceway groove.

2. AlGaN/GaN ion PH detecting sensor according to claim 1 is characterized in that channel width is less than 1nm.

3. AlGaN/GaN ion PH detecting sensor according to claim 1 is characterized in that passivation layer is SiN, and its thickness is 5-10nm.

4. AlGaN/GaN ion PH detecting sensor according to claim 1 is characterized in that, the thickness of GaN layer is 3-5 μ m, and the thickness of AlGaN layer is 5-10nm.