TW201616546A - Gas guiding ring, gas supply device and plasma processing device - Google Patents

Abstract

The present invention discloses a gas guiding ring applicable to the operation of introducing multipath reaction gas into a plasma reaction chamber. The gas guiding ring includes a circular body, a plurality of circular gas channels engaged with the circular body and corresponding to the multipath reaction gas, and a plurality of jet hole sets correspondingly connected with the circular gas channels and independent of each other. The gas inlet of each jet hole of each jet hole set is connected with the corresponding circular gas channel, and the gas outlet is formed on the inner wall of the circular body. The gas output directions of at least two jet hole sets are arranged in different ways. The present invention is capable of reacting to the gas field distribution of gas and thereby improving the uniformity of plasma processing.

Description

Gas guiding ring, gas supply device and plasma processing device

The present invention relates to a semiconductor processing apparatus, and more particularly to a gas guiding ring and a gas supply device and a plasma processing apparatus having the gas guiding ring.

In recent years, with the development of semiconductor manufacturing processes, the integration and performance requirements of components are becoming higher and higher. Plasma Technology is widely used in many semiconductor processes by exciting plasma generated by reactive gases. In deposition processes (such as chemical vapor deposition) and etching processes (such as dry etching), they play an important role in the field of semiconductor manufacturing. Generally, in a plasma processing apparatus, a plasma is generally formed by a radio frequency excitation of a reaction gas discharged from the top of a reaction chamber, and then a plasma is bombarded by a bias of an electrostatic chuck to cause a plasma to be bombarded on a chuck. A process of etching, depositing, etc. of the wafer is realized.

Figure 1 shows a schematic structural view of a plasma processing apparatus. The plasma processing device comprises a reaction chamber 2 and an insulating cover plate 1 located above the reaction chamber 2. The gas supply device 5 is disposed between the insulating cover plate 1 and the reaction chamber 4, and the gas supply device 5 is connected to the reaction chamber. A reaction gas source 4 other than 2 is used to introduce the reaction gas in the reaction gas source 4 into the reaction chamber 2. An electrostatic chuck 6 for placing a semiconductor wafer to be processed is disposed in the reaction chamber 2, and the electrostatic chuck 6 is connected to the RF bias power source 9. An inductive coil 3 connected to the RF power source 8 is disposed above the insulating cover plate 1. The induced magnetic field generated by the RF power source 8 induces an RF electric field in the axial direction of the inductor coil 3, and the electric field excites electrons in the reaction chamber. They collide with gas molecules of the reactive gas to produce a plasma of the reactive gas, which reacts with the semiconductor wafer for plasma processing such as etching or deposition. The reaction chamber 2 is connected to an external exhaust device 7 (for example, a vacuum pump) for drawing the used reaction gas and by-product gas out of the reaction chamber 2 during the process.

Figures 2a and 2b show a gas guide ring of the prior art. As shown in Fig. 2a, the gas guiding ring has an annular body 10, a gas passage 11 and a plurality of gas injection holes 12. The inlet of the gas passage 11 is connected to the reaction gas source 4, and the inlet of the gas injection hole 12 communicates with the outlet of the gas passage 11, and the outlet port is provided on the inner side wall of the annular body 10. The reaction gas is supplied from the reaction gas source 4 to each of the gas injection holes 12 through the gas passage 11, thereby being injected into the plasma reaction chamber 2. Referring to FIGS. 2a and 2b, on the horizontal surface of the annular body 10, the gas injection holes 12 are horizontally disposed toward the center of the annular body 10, so that the reaction gas is directly discharged toward the central portion of the annular body 10.

However, due to the introduction of reactive gases or uneven plasma distribution in the reaction chamber 2, different regions on the surface of the semiconductor wafer tend to have different processing rates; for different regions distributed along the radial direction of the wafer, such as the central region. And the edge region, this uneven processing is particularly noticeable, which in turn leads to different performance of the semiconductor elements formed in different regions on the wafer, and has a great influence on the process control of the semiconductor device manufacturing and the product yield.

Therefore, there is a need for a device that is capable of adjusting plasma uniformity to improve the above drawbacks.

SUMMARY OF THE INVENTION A primary object of the present invention is to overcome the deficiencies of the prior art and to provide a gas supply device that facilitates sufficient dissociation of the reaction gas and increases the density of the plasma.

In order to achieve the above object, the present invention provides a gas flow guiding ring disposed above a reaction chamber of a plasma processing apparatus, and a gas flow divider is disposed between the gas flow guiding ring and a gas supply source, the gas guiding The flow ring is used to input a plurality of reactive gases that are split by the gas splitter and adjusted in flow rate to the reaction chamber. The gas guiding ring includes: an annular body; a plurality of annular gas passages embedded in the annular body corresponding to the plurality of reactive gases, an input end of the plurality of annular gas passages and the a gas splitter connected; and a plurality of sets of gas injection holes corresponding to the plurality of annular gas passages and not interfering with each other, the air inlets of the respective gas injection holes of each group of the gas injection holes and the corresponding annular gas passage The output ends are connected, and an air outlet is formed on the inner side wall of the annular body, wherein the gas ejection directions of the at least two sets of the gas injection holes are set to be different.

Preferably, different sets of the gas outlets of the gas injection holes are formed at different heights of the inner side walls of the annular body.

Preferably, the plurality of sets of gas injection holes include at least a first group and a second group, wherein a gas ejection direction of the first group of gas injection holes is parallel to a horizontal plane of the annular body, and the second group of the gas injection holes The gas ejection direction is at an acute angle to the horizontal plane of the annular body.

Preferably, the gas ejection direction of the second group of gas injection holes is inclined upward or obliquely downward with respect to the horizontal plane of the annular body.

Preferably, each of the gas injection holes has at least an air outlet section communicating with the air outlet, and at least two sets of the axial lines of the air outlet sections of the air injection holes are different from the angle formed by the plane of the annular body.

Preferably, the plurality of annular gas passages are embedded in the annular body in a manner of being radially embedded in the upper or lower stack.

Preferably, each of the gas passages is an annular gas passage, and each set of the gas injection holes is uniformly distributed along a circumference of the corresponding annular gas passage.

Preferably, the cross section of the gas injection hole is a taper having a small air outlet and a small air outlet.

Preferably, for a group of gas injection holes correspondingly connected to each of the annular gas passages, an aperture of the gas injection hole near the input end of the annular gas passage is smaller than an aperture of the gas injection hole away from the input end.

According to another aspect of the present invention, the present invention also provides a gas supply device applied to a plasma processing apparatus, comprising a gas flow divider and the gas flow guide ring, wherein the gas flow divider is disposed in the plasma processing device The outside of the reaction chamber is connected to a source of reactive gas for splitting the reaction gas into multiple channels and adjusting the flow ratio of the multiple reactive gases.

According to another aspect of the present invention, there is also provided a plasma processing apparatus comprising a reaction chamber and the above gas supply device.

The invention has the beneficial effects of adjusting the plasma distribution density of different regions in the reaction chamber of the plasma processing device through the arrangement of the gas passages and the gas jet holes in the gas guiding ring, and improving the uniformity of the semiconductor elements formed in different regions on the wafer.

In order to make the content of the present invention clearer and easier to understand, the contents of the present invention will be further described below in conjunction with the accompanying drawings. Of course, the invention is not limited to the specific embodiment, and general replacements well known to those skilled in the art are also encompassed within the scope of the invention.

Figure 3 shows a plasma processing apparatus using a gas flow guide of the present invention provided by an embodiment of the present invention. It should be understood that the plasma processing apparatus is merely exemplary, it may include fewer or more constituent elements, or the arrangement of the constituent elements may differ from that shown in FIG.

The plasma processing apparatus includes a reaction chamber 12 and an insulating cover 11 above the reaction chamber 12. The insulating cover 11 is typically a ceramic dielectric material. Above the inside of the reaction chamber 12, a gas guide ring 20 is disposed at a level below the insulating cover 11. The gas guiding ring 20 is connected to a gas splitter 19 located outside the reaction chamber 12, which together constitute a gas supply means for the plasma processing apparatus. The gas splitter 10 is connected to the reactant gas source 18 for splitting the reaction gas supplied from the reaction gas source 18 into multiple paths and regulating the gas flow rate of the flow paths, and the gas flow guiding ring is diverted by the gas splitter 19. The flow-regulated multiple reactive gases are input to the reaction chamber 12. An inductive coil 13 connected to the RF power source 14 is disposed above the insulating cover 11. The induced magnetic field generated by the RF power source 14 induces an RF electric field on the inductor 13, which accelerates the electrons in the reaction chamber 12. They collide with gas molecules of the input reaction gas, and these collisions cause ionization of the reaction gas and excitation of the plasma, thereby generating plasma in the cavity 12, and the plasma reacts with the substrate to be processed, such as a semiconductor wafer, to perform Plasma process such as etching or deposition. An electrostatic chuck 15 on which a semiconductor wafer to be processed is placed is disposed inside the reaction chamber 12, and the electrostatic chuck 15 is connected to the RF bias power source 16 to increase the energy of the plasma colliding with the semiconductor wafer. The reaction chamber 12 is connected to an external exhaust device 17, such as a vacuum pump, for drawing spent reaction gases and by-product gases out of the reaction chamber 12 during processing.

With continued reference to FIG. 4, a cross-sectional view of a gas guiding ring in accordance with an embodiment of the present invention is shown. The gas guiding ring 20 includes an annular body 21 in which a plurality of annular gas passages corresponding to the plurality of reactive gases are embedded, and the input ends of the gas passages are respectively connected to the gas splitter 19 through a pipeline. In this embodiment, the gas splitter 19 splits the reaction gas from the reaction gas source 18 into two paths, and adjusts the two reaction gases to have different gas flow ratios, such as one of the channels having a gas flow rate of 90% and the other having 10% gas flow. The gas splitter 19 can perform the above functions through the setting of the flow regulating valve. Correspondingly, two annular gas passages are radially embedded in the annular body 21, and the input ends of the annular gas passages are perpendicular to the plane of the annular body 21 and are respectively separated from the two gases of the flow and the flow rate regulated by the gas splitter 19. The pipeline is connected. In other embodiments, a plurality of annular gas passages may also be embedded in the annular body 21 in a manner of being stacked above, and the input end of the annular gas passage may be parallel to the plane of the annular body 21 and multi-channel gas. The pipeline is connected. The annular body 21 is further provided with a plurality of sets of gas injection holes which do not interfere with each other, and each set of gas injection holes is correspondingly connected to one gas passage. In this embodiment, there are two sets of gas injection holes 23, 25 corresponding to the annular gas passages 22, 24, respectively. Each of the air holes of each set of air holes has an air inlet and an air outlet, and the air inlet is connected to an output end of the corresponding annular gas passage, and the air outlet is formed on the inner side wall of the annular body 21. It should be noted that in the present invention, the group of the gas injection holes has different gas ejection directions of at least two sets of gas injection holes. Thereby, the reaction gas supplied from the reaction gas source 18 is split into two paths by the gas splitter 19 and the gas flow rate ratio is adjusted, and then transmitted to the annular gas passages 22 and 24 via the pipeline, respectively, and then sent to the two sets of gas injection holes 23, 25 Therefore, different flow rates of reaction gases are injected into the reaction chamber 12 at different injection angles, so that different regions of the reaction chamber 12 can obtain different gas field distributions and plasma densities, thereby adjusting the radial position of the semiconductor wafer. Plasma distribution. In this embodiment, the annular gas passages 22, 24 are uniformly annular and surround the inner side wall of the annular body 21 by 360 degrees. In other embodiments, the annular gas passage may also be a polygonal ring shape. The cross-sectional shape of the annular gas passage is rectangular, but may be circular, and the present invention is not limited thereto. The number of each group of air holes can be 8~300, which can be evenly distributed along the circumference of the corresponding annular gas channel to ensure the uniformity of gas flow field distribution. The cross-sectional shape of each of the gas injection holes may be a small taper having a large gas outlet opening to increase the discharge flow rate of the reaction gas.

In the present invention, the defects of uneven distribution of plasma density in the prior art are improved by the arrangement of a plurality of annular gas passages and a plurality of sets of gas injection holes. As shown in FIG. 4, in order to prevent the air outlets of the air holes from interfering with each other, the air outlets of the different groups of the air holes are formed at different heights of the inner side walls of the annular body 21. In the present embodiment, the gas injection hole group 23 is located above the gas injection hole group 25, and the annular passage 22 is located radially inward of the annular passage 24. Wherein, the gas ejection direction of the gas injection hole group 25 is parallel to the horizontal surface of the annular body 21 to emit the reaction gas level in the annular passage 24, and the gas ejection direction of the gas injection hole group 23 is at an acute angle with the horizontal surface of the annular body 21, so that The reaction gas in the annular passage 22 is obliquely emitted. As shown, the gas ejection direction of the gas injection hole group 23 is inclined downward with respect to the level of the annular body 21, and its axial line forms an acute angle α with the horizontal surface of the annular body 21. Therefore, the reaction gas ejected from the gas injection holes 23 has an initial velocity toward the center of the gas guiding ring and vertically downward, and the reaction gas ejected from the gas injection holes 25 has only an initial velocity toward the center of the gas guiding ring, and is combined with the gas. By controlling the ratio of the gas flow rate by the splitter 19, the flow rate and direction of the reaction gas introduced in different radial regions of the cavity 12 can be adjusted, thereby improving the uniformity of the plasma treatment on the surface of the semiconductor wafer. 4 is only an embodiment of the present invention. In practical applications, the direction of the air blast holes of each group may be set as needed, for example, the gas ejection direction of the gas vent group 23 may also be inclined with respect to the horizontal plane of the annular body 21. Thus, the gas ejected from the group of the gas injection holes 23 has an upward initial velocity which rises after rising in the vertical direction, thereby increasing the dissociation time of the reaction gas. Further, the gas injection hole group 25 may be disposed obliquely to set the gas injection hole group 23 as long as the gas injection holes of each group are disposed so as not to interfere with other group of gas injection holes or other annular passages.

Further, each of the gas injection holes may be composed of two or more segments. Each of the gas injection holes has at least an air outlet section communicating with the air outlet, and the axial line of the air outlet section may be parallel to the plane of the annular body 21 or form an acute angle to determine the gas discharge direction. The axial line of the outlet section of at least two sets of the gas injection holes is different from the angle formed by the plane of the annular body. The other part of the gas jet hole except the gas outlet section does not affect the gas discharge angle and may have a different direction from the gas outlet section. This design avoids mutual interference between the gas jet hole groups, the gas injection hole group and the annular passage.

As described above, the multiple reactive gases are delivered to the gas injection holes 23, 25 through the respective gas passages 22, 24, and for each group of the gas injection holes, the inlet ports of the respective gas injection holes (that is, their corresponding ones) The path length between the output end of the annular gas passage and the input end of the annular gas passage is different. Due to the difference in the length of this path, the gas pressure and gas flow rate ejected from the respective gas injection holes of the same group are uneven. Therefore, in a preferred embodiment of the present invention, the diameter of the gas injection hole near the input end of the corresponding annular gas passage is smaller than the gas injection hole away from the input end (such as a gas injection hole away from the input end) Aperture. Therefore, the corresponding gas injection hole having a smaller pore diameter near the input end of the annular gas passage slows the reaction gas passage speed, and the corresponding gas injection hole having a larger pore diameter away from the input end of the annular gas passage is favorable for improving the gas passage efficiency. The purpose of achieving uniform gas flow from each of the gas jet holes of each group to the reaction chamber 12 is achieved.

In summary, the gas guiding ring of the present invention adjusts the gas field distribution of the reaction gas in different regions of the plasma processing device by setting the annular gas passage and the gas injection hole, so that the plasma generated by the reaction gas is on the wafer. The upper radial direction can be evenly distributed from the center to the edge position, improving the uniformity of processing at different positions of the wafer and improving the yield of the product.

It can be understood that the gas guiding ring and the gas supply device of the present invention can be applied to various plasma processing devices, such as plasma etching, plasma physical vapor deposition, plasma chemical vapor deposition, plasma surface. Cleaning and other devices.

The present invention has been described in the above preferred embodiments, and the present invention is not intended to limit the scope of the present invention, and is not intended to limit the scope of the invention. A number of changes and refinements may be made, and the scope of protection claimed by the present invention shall be as described in the scope of the patent application.

10‧‧‧ gas splitter
11‧‧‧Insulation cover
12‧‧‧Reaction chamber
13‧‧‧Inductance coil
14‧‧‧RF power source
15‧‧‧Electrostatic chuck
16‧‧‧RF bias power source
17‧‧‧Exhaust device
18‧‧‧Responsive gas source
19‧‧‧ gas shunt
20‧‧‧Gas diversion ring
21‧‧‧ ring body
22‧‧‧Circular gas channel
23‧‧‧jet holes
24‧‧‧Ring channel
25‧‧‧jet holes

1 is a schematic view of a conventional plasma processing apparatus; FIG. 2a is a plan view of a gas supply apparatus of the prior art; FIG. 2b is a cross-sectional view of a gas supply apparatus of the prior art; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 4 is a cross-sectional view showing a gas guiding ring according to an embodiment of the present invention.

11‧‧‧Insulation cover

12‧‧‧Reaction chamber

13‧‧‧Inductance coil

14‧‧‧RF power source

15‧‧‧Electrostatic chuck

16‧‧‧RF bias power source

17‧‧‧Exhaust device

18‧‧‧Responsive gas source

19‧‧‧ gas shunt

20‧‧‧Gas diversion ring

Claims (11)

a gas guiding ring disposed above the interior of the reaction chamber of the plasma processing apparatus, a gas splitter disposed between the gas guiding ring and the gas supply source, the gas guiding ring being used to a gas splitter split and a plurality of reactive gases for proportionally adjusting the flow rate are input into the reaction chamber, wherein the gas flow guiding ring comprises: an annular body; embedded in the annular body, and the multiplexed reaction gas Corresponding plurality of annular gas passages, wherein the input ends of the plurality of annular gas passages are connected to the gas splitter; and the plurality of sets of fumaroles corresponding to the plurality of annular gas passages and not interfering with each other And an air inlet of each of the air holes of each group of air holes is connected to an output end of the corresponding annular gas passage, and an air outlet is formed on an inner side wall of the annular body, wherein at least two groups of the air holes are The gas ejection direction is set to be different. A plasma processing apparatus according to claim 1, wherein the gas outlets of the different groups of the gas injection holes are formed at different heights of the inner side walls of the annular body. The plasma processing apparatus of claim 1, wherein the plurality of sets of gas injection holes comprise at least a first group and a second group, wherein a gas ejection direction of the first group of gas injection holes is parallel to a horizontal plane of the annular body The gas ejection direction of the second group of the gas injection holes is at an acute angle to the horizontal plane of the annular body. The plasma processing apparatus according to claim 3, wherein the gas ejection direction of the second group of the gas injection holes is inclined upward or obliquely downward with respect to a horizontal plane of the annular body. The plasma processing apparatus of claim 1, wherein each of the gas injection holes has at least an outlet section communicating with an outlet thereof, at least two sets of axial lines of the outlet section of the gas injection hole, and the annular body plane The angle formed is different. The plasma processing apparatus of claim 1, wherein the plurality of annular gas passages are embedded in the annular body in a manner of being radially embedded in the upper or lower stack. A plasma processing apparatus according to claim 1, wherein each of said gas passages is an annular gas passage, and each of said plurality of gas injection holes is evenly distributed along a circumference of said corresponding annular gas passage. The plasma processing apparatus according to claim 1, wherein the cross section of the gas injection hole is a taper having a small air outlet and a small air outlet. The plasma processing apparatus of claim 1, wherein for each of the plurality of annular gas passages, a plurality of gas injection holes are connected, and a diameter of the gas injection hole near the input end of the annular gas passage is smaller than a distance from the input end. The aperture of the jet hole. A gas supply device is applied to a plasma processing device, comprising: a gas splitter disposed outside a reaction chamber of the plasma processing device, connected to a reaction gas source, for diverting the reaction gas into multiple channels and The ratio of the flow rate of the multiplexed reaction gas is adjusted; and the gas guide ring according to any one of claims 1 to 9. A plasma processing apparatus comprising a reaction chamber and a gas supply device, the gas supply device comprising: a gas splitter disposed outside the reaction chamber, connected to the reaction gas source for diverting the reaction gas into a plurality And adjusting the ratio of the gas flow of the plurality of channels; and the gas guiding ring according to any one of claims 1 to 9.