CN110148581B

CN110148581B - Metallization process and method of metal-semiconductor

Info

Publication number: CN110148581B
Application number: CN201810136008.9A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Wuxi Ruidao Intelligent Equipment Co.,Ltd.
Priority date: 2018-02-10
Filing date: 2018-02-10
Publication date: 2022-05-17
Anticipated expiration: 2038-02-10
Also published as: CN110148581A

Abstract

The invention belongs to the technical field of semiconductor device manufacturing, and particularly relates to a metallization process and a processing method of a metal-semiconductor electrode. The invention provides a simple process and a corresponding treatment method, which sequentially comprise the following steps: providing a semiconductor substrate, wherein the semiconductor comprises at least one PN junction, the PN junction structure can be a stacked structure, and one or a mixed oxide thin layer and a dielectric film layer are attached to the surface of the semiconductor substrate; directly applying electrode material to one side or two sides of the substrate by sputtering, depositing, electroplating, printing or implanting; the positive and negative electrodes which are connected into a whole and need to be separated are separated by corrosion to generate an externally connected positive and negative electrode; carrying out heat treatment on the semiconductor material covered with the metal electrode; and finally, finishing the metallization process by implementing an ohmic contact method on the external electrode.

Description

Metallization process and method of metal-semiconductor

Technical Field

The invention belongs to the technical field of semiconductor device manufacturing, and particularly relates to a metal-semiconductor electrode metallization process and a technical processing method in the fields of microelectronic manufacturing, semiconductor light-emitting devices and photovoltaic solar cell manufacturing.

Background

An important process in the fabrication of semiconductor devices is the fabrication of low conductive resistance contact electrodes from metals or alloys. The existing electrode structure metallization process manufacturing process in the metal-semiconductor large-scale integrated circuit manufacturing process is tedious, needs expensive photoetching mask flow to selectively chemically corrode a passivation layer, cleans the passivation layer, then sputters a metal film, and then carries out high-temperature annealing and other procedures, and has complex process, high cost, great difficulty in electrode material formula and complex sintering annealing; in order to improve the efficiency of the common photovoltaic solar semiconductor energy battery, the electrode of the common photovoltaic solar semiconductor energy battery needs a metal electrode material with a special formula to form good ohmic body resistance and contact resistance through printing, implanting and burying, and then sintering at high temperature, and the metallization process of the electrode material and the new multilayer passivation film technology have strict requirements on the sintering process, in particular to the problem of low-doped PN junction. In addition, the contact characteristics are also significantly degraded by a natural oxide layer on the surface of the semiconductor at a high temperature and device process pollution, and these factors increase the manufacturing difficulty, the cost and the defective rate of the conductive electrode material.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the metallization process is provided, the electrode metallization process manufacturing process in the existing metal-semiconductor large-scale integrated circuit manufacturing process can be improved at low temperature, the existing photoetching mask process and selective chemical corrosion passivation layer are not needed to reserve a lead hole and a cleaning process, and the metallization is completed by directly carrying out selective ohmic contact on the formed metal electrode-semiconductor; aiming at the existing manufacturing process of the light-emitting semiconductor device and the photovoltaic solar cell, an additional low-temperature ohmic contact process is introduced, so that the low-temperature metallization process can be further realized, the process requirement of the sintering temperature is reduced, the defect generation is reduced, and the output efficiency and the yield of the semiconductor device are improved.

The technical scheme for solving the technical problems comprises the following steps:

the first step, providing a semiconductor substrate, the semiconductor comprises at least one PN junction, the PN junction structure can be a series structure in a superposition form, and one or a mixed oxide thin layer and a dielectric film 3 layer are adhered to the surface of the semiconductor substrate;

further said thin oxide layer, dielectric film 3 layer, having a thickness in the range of 1nm-200nm, may be on one or both sides of the semiconductor material.

Secondly, directly applying electrode materials on the surface of the base material in an evaporation, sputtering, deposition, electroplating, printing, implantation or burying mode;

further, in complex Metal Oxide Semiconductor (MOS) structures in large scale circuits, additional deposition of electrodes is required on the backside.

And thirdly, separating the electrodes of the P region 2 and the N region 1 to be separated by selective corrosion, and forming the electrode of the semiconductor device which can be externally connected.

Fourthly, carrying out heat treatment on the semiconductor material covered with the metal electrode;

further, the required working temperature is 150-800 ℃, which is to improve the adhesion of the conductive electrode material to the thin oxide layer, the dielectric layer, and the semiconductor material, and to reduce the bulk resistance of the metal electrode. Fifthly, completing a metallization process by implementing an ohmic contact treatment method on the externally connected positive and negative electrodes;

further, the required working temperature is room temperature-400 ℃; direct current or induced current of 1-100kA/cm2 is generated by a power supply 6 and is injected into a PN junction of a metal electrode to achieve the aim of ohmic contact, and the action time ranges from nanosecond to second;

in a further direct current injection mode, a forward conducting current within a certain time range is directly applied to the externally connected positive and negative electrodes of the PN junction area of the corresponding semiconductor device through the power supply 6 to form metal-semiconductor ohmic contact;

in another induced current injection mode, an external collimated or focused electron beam or light source is used to generate electrical conduction in a semiconductor material for a certain time range, and an external electrode is used to generate current with a power supply 6, so as to sequentially form metal-semiconductor ohmic contact.

The invention has the beneficial effects that:

the key point of the invention is to provide a metal semiconductor metallization process and a treatment method for semiconductors and photoelectric materials with different metals and different doping types and different concentrations and electrodes of photovoltaic solar cells. Compared with the prior art, the process and the method are simple and effective, can be compatible with the existing production process flow, quickly solve the problem of poor contact in metallization, simplify the semiconductor photoetching production process, simplify the electrode sintering process, and provide a feasible implementation scheme for simplifying the semiconductor integrated circuit manufacturing, the semiconductor light-emitting device manufacturing, the photovoltaic solar cell manufacturing or the integrated photovoltaic module manufacturing.

Drawings

FIG. 1 is a process flow diagram of the present invention;

FIG. 2 is a simple structure of an ohmic contact of a metal-semiconductor electrode;

FIG. 3 illustrates an ohmic contact for a Metal Oxide Semiconductor (MOS) structure;

FIG. 4 illustrates an indirect ohmic contact method for a Metal Oxide Semiconductor (MOS) structure;

Detailed Description

A metallization process and method of metal-semiconductor comprises: firstly, providing a substrate containing a semiconductor PN junction, and simultaneously, attaching an oxide or dielectric film 3 layer on the surface of the substrate; sequentially carrying out electrode implementation or corresponding selective corrosion to form a separated positive and negative electrode structure device; and then sintering and annealing processes are further completed to further improve the metallization process, so that the electrode material has good adhesion, low bulk resistance and semiconductor preliminary devices with external connection capability, and finally the final metallization process is completed by a heater 7 and an ohmic contact method (the flow is shown in detail in fig. 1, and the ohmic contact mode is shown in fig. 2, 3 and 4).

The scope of the invention is further illustrated by the following examples, which are not intended to limit the scope of the invention to the examples.

Example 1 Using the inventive process for a metal-silicon oxide-semiconductor electrode structure

The front surface of the P-type monocrystalline silicon substrate is doped with N-type, silicon nitride is deposited on the surface of the P-type monocrystalline silicon substrate by 80-100nm, positive and negative electrode materials are respectively implanted into the front and rear surfaces, an annealing process is carried out at 800 ℃, and then the effective series resistance of the metal-silicon oxide-semiconductor is 0.01 ohm when the direct current density is about 75A/cm2 and the temperature is 100 ℃.

Example 2 Using the inventive procedure Metal-silicon nitride-silicon oxide-semiconductor electrode Structure for Electrical conduction

The N-type monocrystalline silicon substrate is characterized in that the front surface of the N-type monocrystalline silicon substrate is doped in a P type mode, silicon nitride is deposited on the surface of the N-type monocrystalline silicon substrate by 80-100nm, positive and negative electrode materials are respectively implanted into the front surface and the back surface of the N-type monocrystalline silicon substrate, an annealing process is carried out at 700 ℃, then the induced current density is about 20kA/cm2, and the effective series resistance of the metal-silicon oxide-semiconductor is achieved at room temperature.

Claims

1. A metallization process for metal-semiconductor comprises, in a first step, providing a semiconductor substrate, wherein the semiconductor comprises at least one PN junction, the PN junction structure is a series structure in a superposition mode, and one or a mixed dielectric film layer is attached to the surface of the semiconductor substrate; secondly, directly applying electrode materials on the surface of the dielectric film layer in an evaporation, sputtering, deposition, electroplating, printing, implantation or filling mode; thirdly, separating the electrodes of the P area and the N area which need to be separated by adopting selective corrosion to form a positive electrode and a negative electrode which can be externally connected; fourthly, carrying out heat treatment on the semiconductor substrate covered with the electrode; fifthly, completing a metallization process by implementing an ohmic contact treatment method on the externally connected positive and negative electrodes; the working temperature required by the heat treatment in the fourth step is 150-800 ℃, and the process is to improve the adhesion force of the electrode material and the dielectric film layer and ensure thatThe bulk resistance of the electrode decreases; in the fifth step, the metallization process needs to provide the working temperature of between room temperature and 400 ℃ by using a heater (7); is generated by a power supply (6) to 75A/cm²-20kA/cm²The direct current or the induced current is injected into the PN junction of the electrode to achieve the aim of ohmic contact, and the acting time ranges from nanosecond to second; the direct current injection is to directly apply positive-going conducting current with certain adjustable time to the external positive and negative electrodes of the PN junction of the corresponding semiconductor device through a power supply (6) so as to form metal-semiconductor ohmic contact.

2. The metal-semiconductor metallization process according to claim 1, wherein the dielectric film layer in the first step has a thickness in the range of 1nm to 200nm and is attached to one or both sides of the semiconductor substrate.

3. The metal-semiconductor metallization process according to claim 1, wherein in the second step, an electrode material is applied directly on the surface of the dielectric film layer by sputtering, deposition, plating, printing or implantation; in complex metal oxide semiconductor structures in large scale circuits; the back side of complex mos structures in large scale circuits requires the deposition of electrodes.

4. The metal-semiconductor metallization process according to claim 1, wherein in the third step, the electrodes belonging to different P and N regions are selectively corroded and separated by using a photolithography masking technique for the electrodes of the P and N regions to be separated; and forming the externally connected positive and negative electrodes required in the step five.

5. A metal-semiconductor metallization process according to claim 1, characterized in that the current injection is induced by an external collimated or focused radiation source, i.e. an electron beam or a light source, which generates electrical conduction in the semiconductor substrate for a certain time and at the same time generates a current through external positive and negative electrodes and a power supply (6), which in turn forms a metal-semiconductor ohmic contact.