TWI584341B - Gas delivery device and plasma processing device - Google Patents

Description

Gas delivery device and plasma processing device

The present invention relates to a semiconductor processing apparatus, and more particularly to a gas delivery apparatus and a plasma processing apparatus.

At present, in the plasma process, the reaction gas is usually introduced into the reaction chamber from a gas shower head provided in the upper portion of the reaction chamber of the plasma processing device, and the reaction gas is excited by radio frequency to form a plasma, and then the static electricity is passed through the lower portion of the reaction chamber. The bias of the chuck causes the plasma to bombard the wafer on the chuck, thereby implementing a plasma process such as etching, deposition, etc. of the wafer.

However, due to various reasons such as gas transport, electric field action or pumping unevenness, it is easy to cause the generated plasma to have different distribution densities in different regions on the surface of the semiconductor wafer, thereby generating different processing speeds in different regions of the wafer surface. This unevenness is particularly noticeable for different regions distributed along the radial direction of the wafer, such as the central region and the edge region, which in turn leads to different performance of semiconductor components formed in different regions on the wafer, process control for semiconductor component fabrication, and product yield. It has a big impact.

In order to solve this problem, the prior art proposes a gas splitter which can split the reaction gas into multiple channels of different flow rates, thereby conveying different flow rates of multiple reactive gases to different regions of the gas shower head, so that the reaction chamber Different areas of plasma can be obtained in different areas of the room to improve the uniformity of the entire wafer surface treatment. However, the flow rate of each reaction gas shunted by this gas splitter is the same, such as 10% to 90%, if it is desired to be particularly small for a certain area. The flow ratio, such as 0.5%, is not possible with existing gas splitters.

Therefore, it is desirable to provide a gas delivery device to improve the above drawbacks.

The main object of the present invention is to overcome the deficiencies of the prior art and to provide a gas delivery device capable of delivering different flow rates, particularly small flow rates of reaction gases, to different regions of the reaction chamber of the plasma processing device to improve the control accuracy of the gas flow rate. .

To achieve the above object, the present invention provides a gas delivery device for use in a plasma processing apparatus, the plasma processing apparatus including a reaction chamber including a gas flow splitter and at least one gas regulator. The gas splitter is configured to split the reaction gas into a flow controllable multiplex to output to different gas distribution regions of the gas guiding member located in the reaction chamber; the gas regulator is coupled to the gas splitter and Between the gas guiding members, for receiving one of the reaction gases output through the gas splitter and diverting them into a plurality of branches for output to the gas guiding member corresponding to the reactive gas of the path Different sub-areas within the gas distribution area. The gas regulator includes a plurality of gas transfer lines in communication with different sub-regions of the corresponding gas distribution region, wherein at least one gas transfer line includes at least three branch lines and flow switching elements in parallel, the flow switching element being used The transmission flow and the on and off states of each of the branch lines are controlled to regulate the flow of gas delivered by the gas transmission line.

Preferably, the flow switching element comprises a plurality of current limiting elements and at least two switching elements disposed on the at least three branch lines.

Preferably, the plurality of gas transmission lines include a first gas transmission line and a second gas transmission line, and the second gas transmission line includes first, second and third branch lines connected in parallel and the flow switching element, The flow switching element includes a first portion disposed on the first branch line a current limiting element, a second current limiting element and a first switching element disposed in series on the second branch line, and a third current limiting element and a second switch connected in series on the third branch line element.

Preferably, a fourth current limiting element is disposed on the first gas transmission line.

Preferably, the flow switching element further includes a third switching element disposed in series with the first current limiting element on the first branch line.

Preferably, the gas splitter splits the reaction gas into two reaction gases of a first flow rate and a second flow rate to be output to the first gas distribution region and the second gas distribution region of the gas flow guide, the gas The regulator splits the reaction gas of the second flow into two reaction gases of the third flow rate and the fourth flow rate to be respectively transmitted to the first sub-region and the second sub-region of the second gas distribution region.

Preferably, each of the current limiting elements is a current limiting hole, and each of the switching elements is an on-off valve.

Preferably, each of the restrictor holes has a different size.

Preferably, the gas guiding member is a gas shower head.

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

The invention has the beneficial effects that one of the reaction gases shunted by the gas splitter is switched into a plurality of branches by a gas regulator, and the flow ratio of each branch is controlled by the flow switching element and the design of at least three branch lines connected in parallel, The specific region in the reaction chamber can be supplied with the reaction gas of the required flow rate, and then the plasma distribution density in different regions of the reaction chamber of the plasma processing device can be adjusted according to the demand, and the uniformity of the semiconductor components formed in different regions on the wafer can be improved. .

1‧‧‧reaction chamber

2‧‧‧ gas splitter

21‧‧‧ pipeline

22‧‧‧ flow

3‧‧‧ gas regulator

31‧‧‧ gas transmission pipeline

311‧‧‧Limited orifice

32‧‧‧ gas transmission pipeline

321‧‧‧Limited orifice

322‧‧‧Limited orifice

323‧‧‧Switching elements

324‧‧‧Limited orifice

325‧‧‧ switch valve

32a‧‧‧ branch pipeline

32b‧‧‧ branch pipeline

32c‧‧‧ branch pipeline

4‧‧‧Gas guides

41‧‧‧ gas distribution area

42‧‧‧ gas distribution area

42A‧‧‧Sub-area

42B‧‧‧Sub-area

1 is a schematic structural view of a gas delivery device according to an embodiment of the present invention.

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.

1 shows a gas delivery device of the present invention provided by an embodiment of the present invention. The gas delivery device is applied to a plasma processing device including a reaction chamber 1 in which an upper portion of the reaction chamber 1 is provided with a gas guiding member 4, and the gas guiding member 4 may include a plurality of gas distribution regions. In this embodiment, the gas guiding member 4 is a gas shower head, and in other embodiments, it may be a gas guiding ring or a baffle or the like. The gas delivery device is used to split the reaction gases into different flow rates for different flow distributions to different gas distribution zones of the gas flow guide 4 for introduction into different regions within the reaction chamber. The gas delivery device includes a gas flow divider 2 and a gas regulator 3, and the gas flow divider 2 divides the reaction gas into reaction gases having different flow rates. For example, in the present embodiment, gas distribution zones 41 and 42 are disposed on the gas shower head 4. Then, the gas splitter 2 splits the reaction gas to form two reaction gases having different first flow rates a and second flow rates b, which are respectively output through the lines 21 and 22. The gas splitter 2 may include a gas separator and a flow controller to perform its split and flow regulating functions, and the multiple reactive gases split therethrough may be gases of the same or different composition.

It should be noted that in the present invention, the multiple reactive gases split by the gas splitter 2 are not directly output to the gas shower head 4, and at least one of the reactant gases is further shunted by the gas regulator 3 and the flow rate is adjusted. As shown in FIG. 1, the gas regulator 3 is disposed between the gas splitter 2 and the gas shower head 4, specifically at least one line of the gas splitter 2 for receiving the output through the gas splitter 2. One of the reactive gases is split and split into multiple branches for output to the gas spray The head 4 corresponds to a different sub-region within the gas distribution region of the reactive gas of the path. There may be a plurality of gas regulators 3, which further separate the multiple reactive gases and adjust the flow rate. In the present embodiment, the gas regulator 3 is disposed on the line 22, and the gas distribution region 42 has two sub-regions 42A and 42B, wherein the gas distribution regions 41, 42 correspond to the edge position and center of the gas shower head 4, respectively. Position, and the sub-area 42B of the gas distribution area is closer to the center of the gas shower head than 42A. Of course, in other embodiments, the gas distribution area at the edge of the gas shower head may be divided into a plurality of sub-areas to provide further respectively. Subdivided gas flow. The gas regulator 3 divides one of the reactant gases of the flow rate b into two branches of flow rates b1 and b2 and delivers them to the sub-regions 42A and 42B, which include gas transfer lines 31, 32 in communication with the respective sub-regions. Among them, the gas transfer line 32 includes three parallel branch lines 32a, 32b, 32c, and a flow switching element. The flow switching element is used to control the flow rate and the on and off states of the respective branch lines 32a, 32b, 32c in the gas transfer line 32, thereby allowing the gas flow rate delivered by the gas transfer line 32 to be adjusted. The flow switching element may include a current limiting element and a switching element, wherein the current limiting element is responsible for controlling the maximum gas flow rate of the branch line, the switching element is responsible for controlling the conduction or the cut-off of the branch line, and the gas transmission is performed by the cooperation of the current limiting element and the switching element. Line 32 outputs reactant gases at different flow or flow ratios. The current limiting components in this embodiment and the following are current limiting holes, and the maximum gas flow rate of the limiting orifice output can be determined according to the size of the current limiting hole itself. For example, the larger the diameter of the limiting orifice, the more the gas flow rate is output. Large; each switching element is an on-off valve, which has only two states of opening and closing. In addition, the number of branch lines can be greater than three to achieve a larger flow adjustment range.

As shown in FIG. 1, a flow restricting hole 321 is provided in the branch line 32a, a current limiting hole 322 and a switching element 323 are provided in the branch line 32b, and a current limiting hole 324 and a switching element 325 are connected in the branch line 32c. Thus, by the control of the opening and closing states of the two switching elements 323, 325, four types of arrangement can be realized, that is, both switching valves are closed, the branch lines 32b, 32c are cut off, and the gas flow rate b2 outputted by the gas transfer line 32 is obtained. The flow rate of the gas outputted to the branch line 32a; only the switching element 323 is opened, the branch line 32b is turned on, and the gas flow rate b2 outputted by the gas transfer line 32 is the sum of the gas flows output from the branch lines 32a and 32b; only the switching element 325 is opened, the branch The line 32c is turned on, and the gas flow rate b2 outputted by the gas transfer line 32 is the sum of the gas flows output from the branch lines 32a and 32c; and both switch elements are open, the branch lines 32b, 32c are turned on, and the gas transfer line 32 outputs The gas flow rate b2 is the sum of the gas flows output by the three branch lines. Therefore, by the opening and closing operation of the on-off valve and the maximum output gas flow rate defined by the restriction orifice, the ratio of the gas flow rate b2 to the gas flow rate b can be switched to four, and the split ratio of the gas splitter 2 can be adjusted to adjust the output to The flow rate of the reaction gas in the sub-area 42B. The size of the restriction holes 321, 322, and 324 may be the same or different. It is assumed that the gas flow rate b2 delivered by the gas delivery line 32 can be 4% b, 13% b, 19% b, and 25% b, respectively, in accordance with the selection of the diameter of each of the restriction holes. If the initial total flow rate of the reaction gas is Q=a+b, and the flow through the gas splitter 2, the ratio of the gas flow output from the line 22 is b/(a+b)=10%~90%, then the gas is sprayed to the gas spray. The maximum gas flow rate of the head region 42B is 90% × 25% Q 23% Q, the minimum value is 10% × 4% Q = 0.4% Q, from which it can be seen that the adjustment range of the flow rate of the reaction gas supplied to the region 42B is expanded, and is not limited to 10% to 90% of the commercially available gas splitter. The adjustment range is especially suitable for the supply of small flow reaction gases. Of course, in other embodiments, another on-off valve may be connected in series on the branch line 32a, and the ratio of the gas flow rate of the gas delivery line 32 to the gas flow rate b of the gas transmission line 32 can be realized by the opening and closing operation of the three switching valves. Switching between setpoints enables a wider range of adjustments to the gas flow rate supplied to zone 42B. In such an embodiment, preferably, the size of the restriction orifices 321, 322, and 324 may be set to be different, such that the gas flow rate output by the gas transfer line 32 is controlled to be larger. In addition, as shown in the figure, a gas restricting hole 311 may be disposed on the gas transmission line 31 of the gas regulator 3, and the size of the restricting hole 311 is set according to the gas demand of the sub-area 42A, and the restricting hole 321 The size of the 322 and the size of the 322 can be the same or can be set to be different.

It can be seen from the above that the present invention divides the diverted one-way reaction gas into a plurality of branches by the design of the gas regulator, and installs at least three parallel branch lines on one of the branches and the flow switching element controls the branch. The gas flow rate is correspondingly distributed to the corresponding region of the gas shower head, and the design can realize multiple flow reactants with different flow ratios in the gas guiding device in the reaction chamber of the plasma processing device. The distribution control of the area, compared with the design of only two branch pipelines, increases the number of combinations at the gas flow rate b2, and changes the combination of only two combinations of the two branch pipelines. The use of multiple parallel branch lines can be effective. Achieving a combination of a plurality of different gas flows, in particular, can accurately provide a small flow of gas to a gas distribution area where gas demand is small, thereby obtaining a desired plasma density distribution to meet the needs of different processes. In addition, the arrangement of the switching element and the current limiting element also has the advantages of simple operation and low cost.

It can be understood that the gas delivery 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 the like.

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.

1‧‧‧reaction chamber

2‧‧‧ gas splitter

21‧‧‧ pipeline

22‧‧‧ flow

3‧‧‧ gas regulator

31‧‧‧ gas transmission pipeline

311‧‧‧Limited orifice

32‧‧‧ gas transmission pipeline

321‧‧‧Limited orifice

322‧‧‧Limited orifice

323‧‧‧Switching elements

324‧‧‧Limited orifice

325‧‧‧Switching elements

32a‧‧‧ branch pipeline

32b‧‧‧ branch pipeline

32c‧‧‧ branch pipeline

4‧‧‧Gas guides

41‧‧‧ gas distribution area

42‧‧‧ gas distribution area

42A‧‧‧Sub-area

42B‧‧‧Sub-area

Claims (10)

A gas delivery device is applied to a plasma processing device, the plasma processing device comprising a reaction chamber, wherein the gas delivery device comprises: a gas splitter for splitting the reaction gas into a flow-controllable multi-path to each Separately outputted to different gas distribution regions of the gas guiding member located in the reaction chamber; at least one gas regulator connected between the gas splitter and the gas guiding member, each of the gas regulators Receiving one of the reactive gases output through the gas splitter and splitting it into a plurality of branches for output to different sub-regions in the gas distribution region of the gas guiding member corresponding to the reactive gas of the path, Included in the plurality of gas transmission lines in communication with different sub-regions of the corresponding gas distribution region, wherein at least one of the gas transmission lines includes at least three branch lines and flow switching elements connected in parallel, the flow switching element is configured to control each of the branches The transmission flow rate and the on and off states of the pipeline to regulate the flow of gas delivered by the gas transmission line, the gas The output end of the branch line transmission lines all parallel lines converge to a single, and only correspond to the same sub-region. The gas delivery device of claim 1, wherein the flow switching element comprises a plurality of current limiting elements and at least two switching elements disposed on the at least three branch lines. The gas delivery device of claim 2, wherein the plurality of gas transfer lines comprise a first gas transfer line and a second gas transfer line, the second gas transfer line comprising first, second and third in parallel a branch line and the flow switching element, the flow switching element comprising a first current limiting element disposed on the first branch line, a second current limiting element disposed in series on the second branch line, and a a switching element, and a series of third current limiting element and second switching element disposed on the third branch line. The gas delivery device of claim 3, wherein the fourth gas restriction line is provided with a fourth current limiting element. The gas delivery device of claim 3, wherein the flow switching element further comprises a third switching element disposed in series with the first current limiting element on the first branch line. The gas delivery device of claim 3, wherein the gas splitter splits the reaction gas into two reaction gases of a first flow rate and a second flow rate to output to the first gas distribution region of the gas flow guide member and a second gas distribution region, the gas regulator splits the reaction gas of the second flow into two reaction gases of a third flow rate and a fourth flow rate to be respectively transmitted to the first sub-region of the second gas distribution region And the second sub-area. The gas delivery device of claim 5, wherein each of the current limiting elements is a current limiting hole, and each of the switching elements is an on-off valve. The gas delivery device of claim 7, wherein each of the restriction orifices has a different size. The gas delivery device of claim 1, wherein the gas flow guide is a gas showerhead. A plasma processing apparatus comprising a reaction chamber and the gas delivery device according to any one of claims 1-9.