WO2014121642A1

WO2014121642A1 - Method for ito thin film sputtering process and ito thin film sputtering device

Info

Publication number: WO2014121642A1
Application number: PCT/CN2013/090553
Authority: WO
Inventors: 耿波; 叶华; 文莉辉; 杨玉杰; 夏威; 王厚工; 丁培军
Original assignee: 北京北方微电子基地设备工艺研究中心有限责任公司
Priority date: 2013-02-05
Filing date: 2013-12-26
Publication date: 2014-08-14
Also published as: CN103966557A; CN103966557B; TWI510661B; TW201432078A

Abstract

Provided is a ITO thin film sputtering process, comprising the following steps: S1, before charging a process gas into a reaction chamber, turning on a direct-current sputtering power source to apply a sputtering power to a target, and setting the output voltage of the direct-current sputtering power source to be a pre-set voltage value; S2, after a pre-set time, charging the process gas into the reaction chamber to accomplish glow-starting; and S3, applying a sputtering power to the target via the direct-current sputtering power source to perform the sputtering process. Also provided is an ITO thin film sputtering device applying the above-mentioned process steps to sputter an ITO thin film.

Description

ITO thin film sputtering process method and germanium thin film sputtering equipment

The present invention relates to the field of semiconductor processing technology, and in particular to a germanium thin film sputtering process and a germanium thin film sputtering apparatus. Background technique

In recent years, GaN-based LEDs (GaN-based LEDs) have been widely used in high-power lamps, automotive instrument displays, and large-area applications due to the huge market demand for Light-Emitting Diodes (LEDs). Outdoor displays, signal lights, and general lighting.

In the GaN-based LED chip manufacturing process, low transmittance of P-type GaN and low transmittance of P-type ohmic metal contact will cause high contact resistance and low transmittance, which seriously affects the overall performance of the LED chip. . In order to improve light extraction efficiency and reduce contact resistance, it is necessary to develop a transparent conductive film suitable for P-type GaN. Indium Tin Oxide film (hereinafter referred to as ITO film) has the advantages of high visible light transmittance, good electrical conductivity, abrasion resistance, corrosion resistance, etc., and is viscous between ITO film and GaN. Due to these characteristics, ITO is widely used as an electrode material for GaN-based chips.

The preparation method of the ITO film includes spray coating, chemical vapor deposition, evaporation coating, magnetron sputtering, and the like. Among them, the ITO film prepared by the magnetron sputtering method has wide application because of its low resistivity, high visible light transmittance and high repeatability.

The prior art DC magnetron sputtering apparatus mainly comprises a reaction chamber body, a vacuum pump system, a substrate carrying a wafer, a DC sputtering power source, and a target sealed on the reaction chamber body. Among them, the process parameters used in the sputtering process are generally: Kaihui and sputtering gas pressure: 2.8 mTorr (mTorr, lTorr = 133Pa); sputtering power: 650W; target power density: 0.5W/cm2. During the sputtering process using the DC magnetron sputtering device, the DC sputtering power source applies sputtering work to the target. The rate is such that a negative bias is formed on the target to cause a process gas glow discharge in the reaction chamber to generate a plasma. When the energy of the plasma is high enough, the metal atoms escape the surface of the target and deposit on the wafer.

However, in practical applications, the sputtering process using the above-described DC magnetron sputtering device may cause the following problems in practical applications: The negative bias of the target during the start-up phase is very high, in other words, the DC sputtering power supply is activated. The output voltage of the glow stage is higher than the preset voltage of the DC sputtering power supply. For example: If the DC sputtering power supply uses 650W output power to start the illumination, the instantaneous ignition voltage of the target is about 1000V. Because the higher instantaneous ignition voltage causes the energy of the sputtered particles to be too high, the bombardment force of the sputtered particles on the P-type GaN film layer is too large, causing damage to the GaN film layer, thereby causing contact between the ITO and the GaN layer. The resistance is too large; excessive contact resistance can cause the LED chip to have a high driving voltage and generate more heat, and attenuate the performance of the LED device. In addition, the damage of the GaN film layer will also cause the forward voltage (VF) value of the LED device to be too high. In severe cases, the VF value will rise to 6.5V or higher (the industry standard is generally 2.9-3.5V), resulting in serious device performance. decline. In addition, because the ITO target is prone to "poisoning" of the target during the deposition process, the target produces a nodule.

To this end, in the prior art, it has been proposed to provide a baffle between the target and the base. When the DC sputtering power source exerts power on the target to initiate the illuminating, the high-energy particles formed at the instant of priming first bombard the baffle plate, thereby avoiding damage to the GaN film layer. After a few seconds of ignition, the baffle is removed and normal sputtering is performed. However, this has the problem that the addition of the baffle not only reduces the uniformity of the TIO film, but also complicates the structure and operation of the device and increases the cost. Summary of the invention

It is an object of the present invention to provide an ITO thin film sputtering process and an ITO thin film sputtering apparatus. The method can greatly reduce the instantaneous ignition voltage during the process of sputter deposition of the ITO film, thereby avoiding excessive bombardment of the GaN layer due to excessive particle energy at the instant of initiation, thereby effectively reducing damage to the GaN layer. Moreover, since there is no need to add a new mechanism, this not only improves the uniformity of film deposition, but also reduces the structure and operation of the device, thereby reducing the manufacturing cost of the device. And labor costs.

To achieve the above object, the ITO thin film sputtering process provided by the present invention comprises the following steps: S1, before a process gas is introduced into the reaction chamber, a DC sputtering power source is turned on to apply a sputtering power to the target, and The output voltage of the DC sputtering power source is set to a predetermined voltage value; S2, after a predetermined time elapses, a process gas is introduced into the reaction chamber to complete the ignition; S3, the DC sputtering power source is applied to the target The sputtering power is applied to the material to perform a sputtering process.

Preferably, in step Si t , the sputtering power is 300W.

Preferably, in step Si t , the sputtering power is 650W.

Preferably, the predetermined voltage value is 800V.

Preferably, the predetermined voltage value is 300V.

Preferably, the predetermined time is 3 to 6 seconds.

Preferably, in step S3, the power value of the sputtering power of the DC sputtering power source is increased to be greater than the power value of the sputtering power in the step S1, and is less than or equal to the DC sputtering power source. Rated power value.

Preferably, in the process of performing steps S1 to S3, the process gas pressure in the reaction chamber is 2 to 5 mTorr.

Preferably, the process gas pressure is 2.8 mTorr.

As another technical solution, the present invention further provides an ITO thin film sputtering apparatus, comprising: a reaction chamber, the reaction chamber includes a top wall, a substrate supporting member, and a target, wherein the target is disposed on the a top wall and a substrate supporting member disposed at a bottom of the reaction chamber, wherein the ITO thin film sputtering apparatus further includes a DC sputtering power source, and the DC sputtering power source is coupled to the target The sputtering power is applied to the target, and the ITO thin film sputtering apparatus applies a thin film sputtering process to the substrate by the above-described ITO thin film sputtering process provided by the present invention.

The invention has the following beneficial effects:

The ITO thin film sputtering process method provided by the present invention deposits an ITO thin film on a GaN layer by a magnetron sputtering process. During the deposition process, there is no process in the reaction chamber On the premise of the gas, the sputtering power is first applied to the target, and the output voltage of the DC sputtering power source is set to a predetermined voltage value, and the process gas and oxygen can be introduced into the reaction chamber after a predetermined time. In the case of radiance, the peak value of the illuminating voltage is lowered, thereby avoiding excessive bombardment of the GaN layer due to excessive energy of the sputtered particles, thereby reducing bombardment damage to the GaN layer, thereby not only The contact resistance between the ITO film and the GaN layer is reduced, and the chip driving voltage can also be lowered, thereby improving the overall performance of the chip. Moreover, since it is not necessary to add a new mechanism, it not only improves the uniformity of film deposition, but also the structure and operation of the device, thereby reducing the manufacturing cost and labor cost of the device.

The ITO thin film sputtering apparatus provided by the invention not only can avoid the high energy of the particles at the instant of priming by coupling the direct current sputtering power source to the target material and using the above ITO thin film sputtering process provided by the invention. The bombardment force on the GaN layer is too large, thereby effectively reducing the damage to the GaN layer. Moreover, since it is not necessary to add a new mechanism, it not only improves the uniformity of film deposition, but also the structure and operation of the device, thereby reducing the manufacturing cost and labor cost of the device. DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing a method of sputtering an ITO thin film according to an embodiment of the present invention. Fig. 2 is a schematic view showing an ITO thin film sputtering apparatus according to an embodiment of the present invention. detailed description

The embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "transverse", "long" Degree,,,"width,,""thickness,","up","below","before","after","left","right","vertical,","jflat"," The orientation or positional relationship of the top, "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present invention and The description of the present invention is not intended to be a limitation of the invention.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include one or more of the features, either explicitly or implicitly. In the description of the present invention, the meaning of "plurality" is two or more, unless specifically defined otherwise.

In the present invention, the terms "installation", "connected", "connected", "fixed" and the like should be understood broadly, and may be either a fixed connection or a detachable connection, unless otherwise explicitly stated and defined. , or connected integrally; can be mechanical or electrical; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of the two components. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood on a case-by-case basis.

In the present invention, the first feature "on" or "under" the second feature may include direct contact of the first and second features, and may include first and second features, unless otherwise explicitly defined and defined. It is not in direct contact but through additional features between them. Moreover, the first feature "aboves", "above" and "above" the second feature includes the first feature being directly above and above the second feature, or merely indicating that the first feature level is higher than the second feature. The first feature "below", "below" and "below" the second feature includes the first feature directly below and below the second feature, or merely indicating that the first feature level is lower than the second feature.

The present invention is based on the principle that in the ITO thin film sputtering, since the excessive ignition voltage during the priming process causes the sputtering particles to have higher energy, the sputtering particles are applied to the P-type GaN film layer. The bombardment force is too large, causing damage to the GaN film layer, resulting in excessive contact resistance between the ITO and GaN layers. Therefore, the above technical problem can be solved as long as the above-described ignition voltage can be reduced. The inventor found that: before starting the glow, the process gas is not introduced into the reaction chamber, but the DC sputtering power source is first turned on, and the output voltage of the DC sputtering power source is limited to a small value range; The predetermined time is maintained to ensure a smooth initiation of the subsequent introduction of the process gas into the reaction chamber. In this way, a small ignition voltage can be obtained during the initiation process to avoid excessive energy of the particles at the instant of initiation, thereby reducing the bombardment intensity of the sputtered particles on the GaN layer, thereby effectively reducing the damage to the GaN layer.

The ITO thin film sputtering process provided by the present invention will be described in detail below with reference to FIG. As shown in FIG. 1, the ITO thin film sputtering process method comprises the following steps:

51, before introducing a process gas into the reaction chamber, turning on a DC sputtering power source to apply sputtering power to the target, and setting an output voltage of the DC sputtering power source to a predetermined voltage value;

52, after a predetermined time elapses, introducing a process gas into the reaction chamber, and entering a glow gas of the process gas in the reaction chamber to generate a plasma, thereby completing the initiation;

53. The sputtering power is continuously applied to the target by a DC sputtering power source to perform a sputtering process. Specifically, referring to FIG. 1 , the ITO thin film sputtering process method of the present invention opens a sputter sputtering power source before a process gas is introduced into the reaction chamber, that is, the DC sputtering power source has no process in the reaction chamber. In the case of a gas, sputtering power is applied to the target, and the output voltage of the DC sputtering power source is set to a predetermined voltage value, that is, the output voltage of the DC sputtering power source is limited to a small value range (the numerical range Compared with the prior art, but not lower than the preset minimum voltage value capable of maintaining stable sputtering, a process such as argon (Ar) is introduced into the reaction chamber after a predetermined time has elapsed. Gas and oxygen, in the process of starting the glow, can reduce the peak value of the ignition voltage during the start-up process, to avoid the excessive energy of the particles at the instant of initiation, thereby reducing the bombardment intensity of the sputtered particles on the GaN layer, thereby effectively reducing Damage to the GaN layer. In addition, the above process of applying a sputtering power to the target by the DC sputtering power source without the process gas in the reaction chamber is maintained for a predetermined time, in order to ensure that the sputtering power has been applied to the target and then the process gas is introduced. And the smooth start of the process gas when the process gas is introduced into the reaction chamber.

After the completion of the initiation, the sputtering power is continuously applied to the target by the DC sputtering power source to perform In the thin film sputtering process, the sputtering power in this step is as long as it satisfies the requirements of the thin film sputtering process. The ITO thin film sputtering process provided by the present invention is applicable to, but not limited to, the manufacture of an LED chip, and the ITO film is deposited on the GaN layer by a magnetron sputtering process, and in the process of performing the deposition process, The sputtering power is applied to the target under the premise of the process gas, and the output voltage of the DC sputtering power source is set to a predetermined voltage value, which can be continued for a predetermined time (to ensure that the process gas is subsequently introduced into the reaction chamber) After the smooth start, the process gas and oxygen are introduced into the reaction chamber to start the glow, thereby reducing the peak value of the ignition voltage, thereby avoiding the GaN layer due to the excessive energy of the sputtered particles. The bombardment force is too large, thereby reducing the bombardment damage to the GaN layer, not only reducing the contact resistance between the ITO film and the GaN layer, but also reducing the chip driving voltage, thereby improving the overall performance of the chip. Moreover, since it is not necessary to add a new mechanism, it not only improves the uniformity of film deposition, but also the structure and operation of the device, thereby reducing the manufacturing cost and labor cost of the device.

In a preferred embodiment of the present invention, in step si t, before the process gas is introduced into the reaction chamber, the DC sputtering power source is turned on, and the sputtering power applied to the target is set to 300 W or 650 W; And the output voltage of the DC sputtering power source is set to 800 V (or 300 V), that is, the predetermined voltage value is 800 V or 300 V.

The above step S1 ends after the predetermined time has elapsed, and at the same time, the step S2 is started. Preferably, the predetermined time may be 3 to 6 seconds.

In step S2, a process gas is introduced into the reaction chamber to complete the initiation, and the instantaneous ignition voltage is 324V, which is larger than the prior art (the ignition voltage is 1000V during the startup process). In order to reduce, the particle energy is too high at the instant of initiation, thereby reducing the bombardment intensity of the sputtered particles on the GaN layer, and effectively reducing the damage to the GaN layer.

In step S3, sputtering power is continuously applied to the target by a DC sputtering power source to perform a sputtering deposition process. Preferably, the power value of the sputtering power of the DC sputtering power source is increased to be greater than the power value of the sputtering power in step S1 and less than or equal to the rated power value of the DC sputtering power source. Of course, in practical applications, it is also possible to keep the sputtering power of the DC sputtering power source unchanged, that is, the steps The power value of the sputtering power in S3 is equal to the power value of the sputtering power in step S1.

In a preferred embodiment of the present invention, preferably, in the process of performing steps S1 to S3, the process gas pressure in the reaction chamber is 2 to 5 mTorr, further preferably 2.8 mTorr, thereby ensuring the process. The gas illuminates smoothly in the reaction chamber.

It can be seen from experiments that the ITO thin film sputtering process provided by the present invention can be used to avoid the excessive energy of the particles at the instant of initiation, thereby reducing the bombardment intensity of the sputtered particles on the GaN layer and effectively reducing Damage to the GaN layer.

The ITO thin film sputtering apparatus of the present invention will be described below with reference to Fig. 2 . The apparatus is a thin film sputtering process for a substrate in accordance with the above-described ITO thin film sputtering process provided by the present invention.

An ITO thin film sputtering apparatus according to an embodiment of the present invention includes a reaction chamber 1 and a DC sputtering power source (not shown).

The reaction chamber 1 includes a top wall 11, a cavity 12, a substrate supporting member 13, and a target 2. The cavity 12 may be a cylindrical cavity; the target 2 is disposed on the top wall 11 and opposite to the substrate supporting member 13 provided at the bottom of the reaction chamber 1; a substrate supporting member 13 such as a base is disposed in the cavity 12 The bottom of the inner portion is used to support the substrate 7.

As shown in FIG. 2, a process gas source 4 is further disposed outside the cavity 12 for supplying a process gas such as argon into the cavity 12, and a flow meter may be disposed between the process gas source 4 and the cavity 12. 5. A flow rate for detecting a process gas flowing out of the process gas source 4. In addition, a vacuum pump system 6 is provided outside the chamber 12, and the vacuum pump system 6 can evacuate the chamber 12. It will be appreciated that the substrate support member 13, the process gas source 4, the vacuum pump system 6, and the like are well known in the art and are well known to those skilled in the art and will not be described in detail herein.

A DC sputtering power source is coupled to the target 2 for applying sputtering power to the target 2.

The ITO thin film sputtering apparatus provided by the invention not only can avoid the high energy of the particles at the instant of priming by coupling the direct current sputtering power source to the target material and using the above ITO thin film sputtering process provided by the invention. The bombardment force on the GaN layer is too large, thereby effectively reducing the damage to the GaN layer. Injury. Moreover, since it is not necessary to add a new mechanism, it not only improves the uniformity of film deposition, but also the structure and operation of the device, thereby reducing the manufacturing cost and labor cost of the device.

It should be noted that other configurations such as magnetrons and the like in the ITO thin film sputtering apparatus of the present invention are known in the art and are well known to those skilled in the art and will not be described in detail herein.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means the specific features described in connection with the embodiments or examples. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, it is understood that the foregoing embodiments are illustrative and not restrictive Variations, modifications, alterations and variations of the above-described embodiments are possible within the scope of the invention.

Claims

claims

1. An ITO thin film sputtering process method, characterized by including the following steps:

51. Before introducing the process gas into the reaction chamber, turn on the DC sputtering power supply to apply sputtering power to the target, and set the output voltage of the DC sputtering power supply to a predetermined voltage value;

52. After the predetermined time has elapsed, process gas is introduced into the reaction chamber to complete ignition;

53. Apply sputtering power to the target through the DC sputtering power supply to perform the sputtering process. 2. The ITO thin film sputtering process method according to claim 1, characterized in that, in step S1, the sputtering power is 300W.

3. The ITO thin film sputtering process method according to claim 1, characterized in that, in step S1, the sputtering power is 650W.

4. The ITO thin film sputtering process method according to claim 2 or 3, characterized in that the predetermined voltage value is 800V.

5. The ITO thin film sputtering process method according to claim 2 or 3, characterized in that the predetermined voltage value is 300V.

6. The ITO thin film sputtering process method according to claim 1, characterized in that the predetermined time is 3 to 6 seconds.

7. The ITO thin film sputtering process method according to claim 1, characterized in that, in step S3, the power value of the sputtering power of the DC sputtering power supply is increased to be greater than that in step S1. The power value of the sputtering power is less than or equal to the rated power value of the DC sputtering power supply.

8. The ITO thin film sputtering process method according to claim 1, wherein during steps S1 to S3, the process gas pressure in the reaction chamber is 2 to 5 mTorr.

9. The ITO thin film sputtering process method according to claim 8, characterized in that the process gas pressure is 2.8 mTorr.

10. An ITO thin film sputtering equipment, including: a reaction chamber, the reaction chamber includes a top wall, a substrate support member and a target material, the target material is disposed on the top wall and is in contact with the reaction chamber The substrate support components at the bottom of the chamber are opposite to each other. The ITO thin film sputtering equipment further includes a DC sputtering power supply. The DC sputtering power supply is coupled to the target material and is used to apply sputtering to the target material. radio power, and

The ITO thin film sputtering equipment applies the ITO thin film sputtering process method described in any one of claims 1 to 9 to perform a thin film sputtering process on the substrate.