JPH09428U - Sputtering equipment - Google Patents

Abstract

(57) [Summary] [Purpose] In the sputtering equipment for semiconductor mass production,
A thin film of stable film quality is deposited on the substrate. A sputtering apparatus for generating a plasma discharge in vacuum and depositing a thin film on a substrate 2 is provided with a cylindrical peripheral shield 6 that hermetically surrounds a plasma discharge generation space 16. A gas passage is provided inside,
A gas introduction mechanism 12 for process gas having a gas outlet is provided on the inner peripheral surface thereof. A ring-shaped or cylindrical passage 14 surrounding the plasma discharge space 16 inside the peripheral shield 6,
17 is provided, the passages 14 and 17 are connected to the gas introduction mechanism 12, and a plurality of gas outlets 14a and 1 are provided in the passages.
It is also possible to form 7a. Further, the gas diffusion means 15 may be provided on the front surface of the gas outlet. Further, a pressure measuring device 13 having an introduction hole is provided on the inner peripheral surface of the shield 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sputtering apparatus, and more particularly to a sputtering apparatus suitable for stabilizing the quality of a thin film deposited on a substrate.

[0002]

[Prior art]

 The structure inside the processing chamber of the conventional sputtering apparatus will be described.

FIG. 7 shows a first configuration example. This sputtering apparatus has a face-down method and a side sputtering method to reduce the influence of particles. Reference numeral 51 is a processing chamber, 52 is a target, 53 is a target holder, 54 is a ring-shaped target shield, 55 is a substrate, 56 is a substrate holder, 57 is a ring-shaped substrate holder shield, and 58 is a cylindrical peripheral shield. When depositing a thin film on the surface of the substrate 55, the substrate holder 56 is placed in a vertical posture as shown by the solid line in FIG. 7, and plasma discharge 59 is generated between the substrate 55 and the target 52 to deposit. When transporting the substrate 55, the substrate holder 56 is placed in a horizontal position (shown by a broken line), and the substrate 55 is transported by a transport mechanism (not shown) with the processing surface of the substrate 55 facing downward. Therefore, the substrate holder 56 changes its posture as indicated by an arrow 60 in correspondence with the case of thin film deposition and the case of substrate transport. According to the face-down method, the processed surface of the substrate 55 faces downward during transportation, so that particles can be prevented from adhering to the processed surface, and according to the side sputtering method, the particles can be prevented from adhering to the substrate and the target by the action of gravity. It becomes difficult to adhere to. Therefore, the influence of particles can be reduced. Incidentally, 61 is a gas introduction mechanism for introducing the process gas 62 into the processing chamber 51, and 63 is another shield.

FIG. 8 shows a second configuration example. With this improved sputtering system, the improvement of technology has made it possible to reduce the number of particles, so the face-up method is used for substrate transport and thin film deposition. In FIG. 8, elements that are substantially the same as the elements described in FIG. 7 are given the same reference numerals, and detailed description thereof will be omitted. Further, in the processing chamber of this sputtering apparatus, for example, two kinds of process gases 62A and 62B are introduced, two gas introduction mechanisms 61A and 61B are provided, and a vacuum gauge 65 for measuring the pressure inside the processing chamber is additionally provided. Has been done.

[0005]

[Problems to be solved by the device]

 In the conventional sputtering apparatus having the first configuration example, since the face-down transfer and the side sputtering are adopted as a countermeasure against particles, the transfer system becomes complicated and the volume of the processing chamber inevitably increases. have. Further, in order to prevent the film from wrapping around, a shield is provided at a place where the film may be attached, so that the shield is increased, the number of parts is increased as a whole, and the number of maintenance steps is increased. Further, the processing chamber has a large volume, so that it has a drawback that the evacuation time becomes long.

In the sputtering apparatus having the second configuration, the volume and surface area of the processing chamber can be reduced, so that the exhaust time can be shortened and the number of shields can be reduced by integrating the shields, which reduces maintenance time. It has the advantage that it can be shortened. However, since the film is prevented from wrapping around and the shield is integrated, the cylindrical peripheral shield 58 has a substantially hermetic structure, and the gas introduction mechanism is arranged only at the processing chamber side and the substrate holder side. Therefore, the process gas cannot be sufficiently introduced into the plasma discharge space. Further, since the vacuum gauge 65 must be attached to the wall portion of the processing chamber due to its structure, it is impossible to accurately measure the pressure in the plasma discharge space. From the above, the second configuration has a problem that the gas pressure during sputtering is not stable and stable film quality cannot be obtained in the thin film deposited on the substrate.

An object of the present invention is to provide a sputtering apparatus capable of depositing a thin film having stable film quality on a substrate.

[0008]

[Means for Solving the Problems]

 The sputtering device according to the present invention is a sputtering device that generates a plasma discharge in a vacuum and deposits a thin film on a substrate. The sputtering device surrounds a plasma discharge generation space and is arranged to substantially seal the generation space. A cylindrical perimeter shield is provided, and an annular gas passage surrounding the plasma discharge space is provided inside the perimeter shield. The gas passage is connected to the process gas introduction mechanism and a plurality of gas outlets are provided in the gas passage. A mouth is formed and is configured to provide a gas outlet on the inner surface of the perimeter shield.

In the above configuration, preferably, the annular passage formed inside the peripheral shield can be formed as, for example, a ring-shaped or cylindrical passage.

In the above configuration, preferably, a gas diffusion plate is provided in front of the gas outlet, and the process gas blown out from the gas outlet is diffused on the gas diffusion plate.

In the above configuration, preferably, a pressure measuring instrument having a pressure introducing hole formed in the inner peripheral surface of the peripheral shield is provided.

[0012]

[Action]

 In the present invention, a cylindrical surrounding shield is provided that surrounds the space where the plasma discharge is generated in a substantially sealed state, and a gas passage portion connected to the process gas introducing mechanism is formed inside the surrounding shield. The gas passage is an annular passage that surrounds the plasma discharge space, and a plurality of gas outlets are formed. Further, since the gas outlets are formed on the inner peripheral surface of the surrounding shield, the gas passage is formed in the plasma discharge space. Since the process gas can be directly introduced and sufficient process gas can be supplied, the film quality can be stabilized. Further, by forming a plurality of gas outlets, the process gas can be dispersed and supplied, which further contributes to stabilization of the film quality. It is also desirable to dispose a process gas in the plasma discharge space by disposing a gas diffusion plate in front of the gas outlet. Moreover, the pressure introduction hole of the pressure measuring device such as a vacuum gauge is provided on the inner surface of the shield and the pressure of the plasma discharge space is directly measured, so that the pressure fluctuation during sputtering can be accurately measured. .

[0013]

【Example】

 Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the internal structure of a processing chamber of a sputtering apparatus according to the present invention. In FIG. 1, 1 is a processing chamber, which is a vacuum container having an airtight structure. The processing chamber 1 is provided with an entrance / exit portion for loading / unloading a substrate to be processed and a transport mechanism for transporting the substrate, but the illustration thereof is omitted in FIG. 1. Further, when processing the substrate, the processing chamber 1 is maintained in a required vacuum state. Therefore, an exhaust mechanism 8 for exhausting the internal space is provided.

In FIG. 1, reference numeral 2 is a substrate holder, and 3 is a substrate placed on the upper surface of the substrate holder 2 in a face-up state. A target 4 is arranged above the substrate holder 2 and the substrate 3. The target 4 is arranged substantially parallel to and facing the processed surface of the substrate 3. 5 is a target presser foot. A space 16 formed between the substrate 3 and the target 4 is a space for generating plasma discharge, and a cylindrical peripheral shield 6 is disposed around the space 16. Although the peripheral shield 6 is fixed, the structure for supporting the peripheral shield 6 is not shown. 7 is a ring-shaped target shield. The gap between the perimeter shield 6 and the target shield 7 is relatively narrow, and the gap between the perimeter shield and the substrate holder 2 is also narrowed. As a result, the perimeter shield is substantially sealed. It has a structure.

The processing chamber 1 is provided with, for example, two mechanisms for introducing a process gas (for example, Ar, N ₂ ) for performing the sputtering process. The first process gas 9 is introduced by the gas introduction mechanism 10 that introduces gas into the lower space of the substrate holder 2, and the second process gas 11 is introduced by the gas introduction mechanism 12. The first process gas 9 introduced into the lower space of the substrate holder 2 passes through the surrounding introduction holes (not shown) as shown by the broken line in FIG. 1, and the plasma discharge space 16 above the substrate 3 is discharged. Be led to. Further, the introduction pipe 12a at the front end of the gas introduction mechanism 12 penetrates through the processing chamber wall and further extends to the inside of the peripheral shield 6, and the gas outlet is formed on the inner peripheral surface of the peripheral shield 6. The second process gas introduced by the gas introduction mechanism 12 by this basic structure is the inner space of the surrounding shield 6 as shown by the broken line in FIG. 1, that is, the plasma discharge space 16 between the substrate and the target. Be introduced directly into. The specific structure of the gas blowing portion of the peripheral shield 6 of the gas introduction mechanism 12 will be described later. Further, an introduction hole of a vacuum gauge 13 for measuring pressure is further provided on the inner peripheral surface of the peripheral shield 6, and the introduction hole is provided so as to face the inner space of the peripheral shield 6, that is, the plasma discharge space. The vacuum gauge 13 is, for example, a diaphragm type vacuum gauge for accurately measuring a pressure range of about 0.1 mTorr to 20 mTorr.

Based on the above configuration, since the process gas 11 can be directly introduced into the plasma discharge space inside the peripheral shield 6 having the closed structure by the gas introduction mechanism 12, the process gas 11 can be stably and sufficiently supplied. Can be supplied. Further, since the pressure of the plasma discharge space inside the peripheral shield 6 can be directly measured by the vacuum gauge 13, the accurate pressure can be measured.

Next, the structure of the peripheral shield 6 of the gas introduction mechanism 12 will be specifically described.

The structure shown in FIG. 2 shows the structure shown in FIG. 1, and the gas outlet at the tip of the introduction pipe 12 a of the gas introduction mechanism 12 is formed only once on the inner peripheral surface of the peripheral shield 6. Then, the process gas 11 is blown out from the gas blowout port into the inner space of the peripheral shield 6. The number of gas outlets can be increased by increasing the number of introduction pipes.

Further, as shown in FIGS. 3 and 4, a ring-shaped passage 14 connected to the introduction pipe 12 a is provided inside the peripheral shield 6, and the peripheral shield 6 is provided on the inner peripheral surface side of the passage 14. It is also possible to form a plurality of small holes 14a communicating with the inner space of the. The plurality of small holes 14a are formed at equal intervals or appropriate intervals. Each of the plurality of small holes 14a serves as a gas outlet. According to this structure, the process gas 11 introduced by the gas introduction pipe 12a passes through the ring-shaped passage 14 and is introduced into the inner space of the peripheral shield 6 from each small hole 14a. Therefore, the process gas 11 can be uniformly dispersed and introduced into the plasma discharge space inside the peripheral shield 6.

In the structure shown in FIG. 5, in the structure shown in FIG. 2, the diffusion plate 15 is arranged at a position in front of the gas outlet of the gas introduction pipe 12a. By providing this diffusion plate 15, the process gas can be diffused and introduced into the inner space of the peripheral shield 6. The diffusion plate 15 also functions as a shield member at the same time.

As shown in FIG. 6, in the peripheral shield, instead of the ring-shaped passage 14 shown in FIG. 4, a passage 17 and a small hole 17a having a cylindrical shape can be formed.

In each of the above-described embodiments, the perimeter shield 6 can be made by integral processing, or can be made by separate assembly.

[0024]

[Effect of the invention]

 As is apparent from the above description, according to the present invention, the process gas introduction mechanism is provided so that the gas outlet is formed on the inner peripheral surface of the peripheral shield that hermetically surrounds the plasma discharge space. Introduces a stable amount and a sufficient amount is introduced, and the quality of the thin film deposited on the substrate is stabilized. Further, the process gas introduced in the plasma discharge space can be dispersed by increasing the number of gas outlets, or can be diffused by providing a diffusion plate or the like, whereby the stabilization of the film quality can be further enhanced. Furthermore, since the pressure in the plasma discharge space is directly measured with a pressure gauge such as a vacuum gauge, accurate pressure information can be obtained. Therefore, it greatly contributes to stable operation and improvement of yield mainly in the sputtering device for mass production of semiconductors.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an internal structure of a sputtering apparatus according to the present invention.

FIG. 2 is a perspective view showing a peripheral shield.

FIG. 3 is a cross-sectional view showing another embodiment of the perimeter shield.

4 is a vertical cross-sectional view of the perimeter shield shown in FIG.

FIG. 5 is a vertical sectional view showing another embodiment of the peripheral shield.

FIG. 6 is a vertical sectional view showing another embodiment of the perimeter shield.

FIG. 7 is a diagram showing an internal structure of a conventional sputtering apparatus.

FIG. 8 is a diagram showing an internal structure of another conventional sputtering apparatus.

[Explanation of symbols]

 1 Processing Chamber 2 Substrate Holder 3 Substrate 4 Target 6 Surrounding Shield 8 Exhaust Mechanism 9, 11 Process Gas 10, 12 Gas Introducing Mechanism 13 Vacuum Gauge 14 Ring-shaped Passage 14a, 17a Small Hole 15 Diffusion Plate 16 Plasma Discharge Space 17 Cylindrical Passage

Claims (3)

[Utility model registration claims] 1. A sputtering apparatus for generating a plasma discharge in vacuum and depositing a thin film on a substrate, wherein the plasma discharge is surrounded by a cylindrical shape and the generation space is substantially sealed. A peripheral shield is provided, an annular gas passage surrounding the plasma discharge space is provided inside the peripheral shield, the gas passage is connected to a process gas introduction mechanism, and a plurality of gas outlets are formed in the gas passage, The sputtering apparatus, wherein the gas outlet is provided on the inner peripheral surface of the peripheral shield. 2. The sputtering apparatus according to claim 1, wherein a gas diffusion plate is provided in front of the gas outlet, and the process gas blown from the gas outlet diffuses on the gas diffusion plate. Sputtering equipment. 3. The sputtering apparatus according to claim 1, further comprising a pressure measuring device having a pressure introducing hole formed on an inner peripheral surface of the peripheral shield.