TWI809280B - Double-station processor and plasma treatment equipment to achieve uniform exhaust - Google Patents

Abstract

A dual-station processor and plasma processing equipment that realizes uniform exhaust. The dual-station processor includes two adjacently arranged plasma processing chambers and a common exhaust pump, and each plasma processing chamber is provided with a gas The injection device and the base for supporting the substrate, the plasma confinement device is arranged around the periphery of the base in each plasma processing chamber, and the exhaust area is arranged under each plasma confinement device, and each plasma processing chamber is connected with the exhaust gas. There are two exhaust passages between the pumps, each exhaust passage has an air inlet and an air outlet, the air inlet is connected to the exhaust area in the plasma processing chamber, and the air outlet is connected to the exhaust pump. The invention improves the uniformity of reaction gas distribution on the substrate surface in the plasma processing equipment, improves the etching uniformity of the substrate, and improves the qualified rate of the substrate.

Description

Double-station processor and plasma treatment equipment to achieve uniform exhaust

The invention relates to a semiconductor device, in particular to a dual-station processor and plasma processing device for realizing uniform exhaust.

In the equipment that uses reactive gas to process semiconductor substrates, such as plasma etching equipment, the reactive gas dissociates into plasma in the reaction chamber to process the semiconductor substrate. As the size of the semiconductor substrate gradually increases, the processing process The accuracy requirements of the semiconductor equipment are constantly improving, and the uniformity of semiconductor substrate processing has become a key parameter to measure whether a semiconductor equipment is qualified or not.

Semiconductor equipment has a complex internal environment, as shown in Figures 1 and 2, in order to improve the efficiency of substrate processing, at least two reaction chambers 70 and 70' can be set on one plasma processing equipment 80, the reaction chamber 70 It is surrounded by the outer wall 71 of the reaction chamber, and the reaction chamber 70' is surrounded by the outer wall 71' of the reaction chamber. A base 30 supporting the substrate 90 is arranged in the reaction chamber 70, a base 30' supporting the substrate 90' is arranged in the reaction chamber 70', and the base 30 and the base 30' have a temperature adjustment function. The gas inlet element 20 connected to the gas supply device 60 feeds the reaction gas into the reaction chamber 70, the gas inlet element 20' connected to the gas supply device 60 feeds the reaction gas into the reaction chamber 70', the external radio frequency source 50 and the external radio frequency source 50' Provides the energy to dissociate the reactive gas into plasma. The temperature adjustment function of the control base, the uniform air intake of the air intake element and the uniform electric field distribution of the external radio frequency source in the reaction chamber can effectively adjust the etching uniformity of the semiconductor substrate, and the exhaust uniformity of the exhaust device can also be Significantly affects the etching uniformity results of semiconductor substrates. The exhaust device 40 is used to discharge the reaction by-products from the reaction chamber while maintaining the pressure in the reaction chamber. In order to maintain the air pressure balance in the reaction chamber, plasma confinement devices 10 and 10' are usually arranged downstream of the reaction chamber. The plasma in the cavity is confined to the working area of the plasma. Plasma confinement devices typically comprise a body and a plurality of holes or slots extending through the body to allow gaseous by-products to escape. The area between the plasma confinement device 10 and the exhaust device 40 is an exhaust area, and the exhaust area surrounds the periphery of the susceptor located at the center of the reaction chamber. Generally, in order to ensure the synchronous operation of the processing processes in different reaction chambers in plasma processing equipment with two reaction chambers, the exhaust areas of the plurality of reaction chambers are often set in fluid communication and are in fluid communication with a common exhaust device 40, so the exhaust The gas device can only be arranged under the adjacent side walls of the two reaction chambers, and the communication between the reaction chamber and the exhaust device 40 is realized through the opening 45. The opening 45 simultaneously penetrates the bottom of the adjacent areas of the two reaction chambers 70 and 70' to realize two reaction chambers. The chambers share an exhaust device 40 to discharge the gaseous by-products generated in the reaction process out of the reaction chamber.

Fig. 3 is a flow velocity distribution diagram of the exhaust area and the exhaust device 40 in a reaction chamber 70' in the plasma processing equipment. Figure 4 is a pressure distribution diagram of the C-C cross-section in Figure 3. Fig. 5 is a flow velocity distribution diagram of the plasma confinement device and the substrate surface in the reaction chamber 70'. It can be seen from Figures 3 to 5 that since the two reaction chambers share one exhaust device 40, in order to ensure the symmetry of the exhaust rates of the two reaction chambers, the exhaust device 40 is arranged adjacent to the two reaction chambers Below the side wall, there is only one exhaust channel 401 between each reaction chamber and the exhaust device 40, and the exhaust channel 401 connects the opening and the exhaust area in the reaction chamber, which will inevitably lead to the exhaust area of the two reaction chambers. The paths of the gas at different positions in the gas to the opening 45 are different, so the gas in the exhaust area near the opening 45 is discharged from the reaction chamber through the exhaust device 40 along the route A, and the discharge rate is relatively fast, and the air pressure in the area here is relatively small. The used reaction gas and by-product gas above the plasma confinement device corresponding to the area will quickly enter the exhaust device 40 through the exhaust channel, and the gas in the exhaust area away from the opening 45 will be discharged through the exhaust device 40 along the B route The reaction chamber, whose discharge rate Slower, the air pressure in this region is higher, and the used reaction gas and by-product gas above the plasma confinement device corresponding to this discharge region will enter the exhaust device 40 through the exhaust channel relatively slowly, from Figure 3 and Figure 4 It can be seen that the flow rate in the middle of the exhaust channel 401 is the fastest. It can also be seen from FIG. 5 that in the processing area above the substrate, the gas flow rate on the side close to the exhaust channel 401 is significantly greater than that on the side farther from the exhaust channel 401. This will lead to uneven gas distribution in the processing area above the plasma confinement device, which in turn affects the uniformity of gas distribution on the surface of the semiconductor substrate, resulting in uneven processing of semiconductor substrates in different areas and reducing the qualification of the semiconductor substrate. Rate.

The present invention provides a dual-station processor and plasma processing equipment for realizing uniform exhaust, which improves the uniformity of the distribution of reaction gas on the surface of the substrate in the reaction chamber of the plasma processing equipment, and improves the uniformity of etching of the substrate. And the qualified rate of the substrate is improved.

In order to achieve the above object, the present invention provides a dual-station processor that realizes uniform exhaust. The dual-station processor includes: two adjacently arranged plasma treatment chambers, and a common exhaust pump. A gas injection device and a base for supporting the substrate are arranged in the processing chamber, and a plasma confinement device is arranged around the periphery of the base in each plasma processing chamber, and an exhaust area is arranged under each plasma confinement device, and the plasma confinement device A plurality of gas passages are arranged on the top for discharging gas to the exhaust area. There are two exhaust passages between each plasma processing chamber and the exhaust pump. Each exhaust passage has an air inlet and an air outlet. The port is connected to the exhaust area in the plasma processing chamber, and the gas outlet is connected to the exhaust pump.

Preferably, the exhaust channel is a long straight channel.

Preferably, two exhaust passages are arranged horizontally between each plasma processing chamber and the exhaust pump.

Preferably, the minimum distance between the inlets of the two exhaust channels is greater than or equal to 100mm.

Preferably, the maximum distance between the inlets of the two exhaust channels is less than or equal to the diameter of the circular plasma processing chamber.

Preferably, the maximum distance between the inlets of the two exhaust channels is less than or equal to the diagonal length of the rectangular plasma processing chamber.

Preferably, in the vertical direction, the exhaust pump is arranged below the two plasma processing chambers, and in the horizontal direction, the positional relationship between the exhaust pump and the two plasma processing chambers satisfies: The central point forms a triangle with the central points of the two plasma processing chambers.

The present invention further provides a plasma treatment device for achieving uniform exhaust, including at least one double-station processor, and the gas injection devices in each plasma treatment chamber in each double-station processor are connected to a reaction gas source.

The invention improves the uniformity of reaction gas distribution on the substrate surface in the plasma processing equipment, improves the etching uniformity of the substrate, and improves the qualified rate of the substrate.

10,10',110,110': plasma confinement device

20,20': Intake element

30,30’,130,130’: base

40: exhaust device

45,145: opening

50,50': External RF source

60: Connect the air supply device

70,70’,170,170’: reaction chamber

71,71': Outer wall of the reaction chamber

90,90’,135,135’: Substrate

80,100: Plasma treatment equipment

101,101': Reaction chamber wall

102,102': Plasma treatment area

103,103': Exhaust area

105: side wall

111: diversion body

112,401: gas channel

120,120': Gas sprinkler head

133,133’: Electrostatic Chuck

140: exhaust pump

150,150': RF power source system

160: reactive gas source

180,180': open the valve

190: isolation parts

201: The first exhaust channel

202: Second exhaust channel

Fig. 1 is a schematic structural diagram of a plasma treatment device with two reaction chambers in the prior art.

Fig. 2 is a top view of two vacuum reaction chambers and an exhaust device in Fig. 1.

FIG. 3 is a flow velocity distribution diagram of an exhaust area and an exhaust channel in one of the reaction chambers of the plasma processing equipment in the prior art.

Figure 4 is a pressure distribution diagram of the C-C cross-section in Figure 3.

Fig. 5 is a flow velocity distribution diagram of the plasma confinement device and the surface of the substrate in one of the reaction chambers of the plasma processing equipment in the prior art.

Fig. 6 is a schematic structural diagram of a plasma processing device with a dual-station processor in an embodiment of the present invention.

Figure 7 is a top view of the dual-station processor in Figure 6.

FIG. 8 is a flow velocity distribution diagram of an exhaust area and an exhaust channel in one of the reaction chambers of the plasma processing equipment in FIG. 6 .

Figure 9 is a pressure distribution diagram of the C-C cross-section in Figure 8.

Fig. 10 is a flow velocity distribution diagram of the plasma confinement device and the surface of the substrate in one of the reaction chambers of the plasma processing equipment in Fig. 6.

Fig. 11 is a flow velocity distribution chart corresponding to different azimuth angles in the reaction chamber in Fig. 3 and Fig. 8 .

The preferred embodiments of the present invention will be described in detail below according to FIG. 6 to FIG. 11 .

Fig. 6 is a cross-sectional schematic diagram of a front view of a plasma treatment device with a dual-station processor provided according to an embodiment of the present invention. The plasma treatment device includes two reaction chambers, and the two reaction chambers One exhaust pump is shared, and two reaction chambers and one exhaust pump together form a dual-station processor. In another embodiment, there may be more than two reaction chambers in the plasma treatment equipment, and the mode that two reaction chambers share one exhaust pump is still used, that is to say, the plasma treatment equipment may contain a plurality of double stations Processors, the structures and exhaust principles of each dual-station processor are similar.

In the plasma processing equipment 100 shown in Figure 6, it includes two adjacent reaction chambers, the reaction chamber 170 is surrounded by the reaction chamber wall 101, the reaction chamber 170' is surrounded by the reaction chamber wall 101', and the two The reaction chambers share an adjacent side wall 105 . In the plasma treatment process, the plasma treatment equipment 100 is usually set in a vacuum environment. When the plasma treatment process starts, the gas injection device injects the reaction gas in the reaction gas source 160 The body is injected into the plasma processing apparatus 100. The gas injection device can have various forms, and can be set as a flat-plate gas shower head or other structures according to different processes and the specific structure of the reaction chamber. In this embodiment, the gas injection device is set as flat-plate gas shower heads 120 and 120 ', the gas shower heads 120 and 120' can evenly inject the reaction gas into the plasma processing equipment, the material of the gas shower head is selected as the material suitable for the electrode, and the gas shower head can be further connected to a radio frequency power supply or grounded as Part of a parallel plate capacitor used to generate plasma. Bases 130 and 130' supporting semiconductor substrates 135 and 135' are respectively set under the gas shower heads 120 and 120', and electrostatic chucks 133 and 133' are usually set above the bases 130 and 130' respectively, through the electrostatic chuck 133 The electrostatic attraction generated by and 133 ′ realizes the fixing of the semiconductor substrate 135 during the plasma treatment process. The pedestals 130 and 130' are generally cylindrical and located at the center of the bottom of the reaction chamber to provide a relatively symmetrical process environment, which is beneficial to the smooth progress of the plasma treatment process. The radio frequency power source system 150 and 150' acts on the bases 130 and 130', and generates an electric field between the gas shower head 120 and the base 130, and between the gas shower head 120' and the base 130', which will generate an electric field from the gas The reaction gas injected by the shower head 120 and the gas shower head 120' dissociates into plasma, and maintains the plasma to act on the semiconductor substrate. The plasma confinement device 110 is disposed around the base 130, and the plasma confinement device 110' is disposed around the base 130'. The regions above the level of the plasma confinement devices 110 and 110' are the plasma processing regions 102 and 102', and the regions below the plasma confinement devices 110 and 110' are the exhaust regions 103 and 103'. Since the two reaction chambers have approximately the same structure, for the convenience of description, the structure of one reaction chamber will be selected for detailed description below. Wherein, the plasma confinement device 110 arranged around the susceptor 130 includes a substantially annular flow guide body 111 and a plurality of gas passages 112 arranged in the flow guide body 111, so as to facilitate the used reaction in the plasma treatment area 102. The gas and by-product gas enter the exhaust area 103 through this gas channel. The used reaction gas and by-product gas contain charged particles and neutral particles. The size of the gas channel 112 is set so that when the charged particles in the plasma pass through the gas channel At 112, charged particles can be neutralized while allowing neutral particles to pass through. The exhaust area 103 is an area surrounding the base 130 . An opening 145 is provided below the two reaction chambers, and the opening 145 communicates with the exhaust pump 140 provided below the two reaction chambers.

As shown in Figure 7, taking one of the reaction chambers as an example, an isolating member 190 is provided at the position of the exhaust passage between the exhaust region of the reaction chamber 170 and the opening 145, thereby separating the complete exhaust passage. For the first exhaust passage 201 and the second exhaust passage 202, the isolation member 190 should be arranged in the middle of the original exhaust passage, so that the first exhaust passage 201 and the second exhaust passage 202 are respectively located on both sides of the isolation member 190, In this way, the part with the fastest flow rate in the original exhaust passage becomes a non-circulating part, and the gas is blocked by the isolation member 190, and cannot enter the exhaust pump 140 from the middle of the original exhaust passage, but can only be transferred from the two sides. The first exhaust passage 201 and the second exhaust passage 202 enter the exhaust pump 140 . Both the first exhaust channel 201 and the second exhaust channel 202 have an inlet and an outlet, the inlet is connected to the exhaust area in the reaction chamber, and the outlet is connected to the exhaust pump 140 . In one embodiment, the first exhaust channel 201 and the second exhaust channel 202 are arranged horizontally between the reaction chamber 170 and the exhaust pump 140 .

In one embodiment, the isolation part 190 can be set in the form of a baffle, that is, a solid part is used to form a barrier to the original exhaust channel. Therefore, one end of the baffle can be fixedly connected to the bottom chamber wall on the side near the opening 145 in a single reaction chamber, and the other end of the baffle can be fixedly connected to the side wall 105 between the two reaction chambers. , or be fixedly connected to the top chamber wall near the opening 145 in a single reaction chamber. The baffle can be in the form of a flat plate, or a curved plate with a certain curvature, or even any form with a certain surface area. In order to obtain a better blocking effect, it is necessary to make It has sufficient width, so the width of the baffle (flat form) or arc length (curved plate form) needs to be greater than or equal to 100mm. There is no limit to the thickness of the baffle, as long as it can block the airflow.

In another embodiment, the isolation member 190 may be further configured in the form of a cavity, that is, the original exhaust channel is divided into a first exhaust channel 201 and a second exhaust channel 202 by hollowing out. This cavity has a side wall, the cross section of the side wall can be a closed curve of any shape, one end of the side wall can be fixedly connected with the bottom cavity wall near the opening 145 side in a single reaction chamber, and the other end of the side wall can be connected with two The side walls 105 between the two reaction chambers are fixedly connected, or are fixedly connected to the top chamber wall near the opening 145 in a single reaction chamber. The width of this cavity also needs to be greater than or equal to 100mm.

As shown in Fig. 7, in order to arrange the isolation part 190 more conveniently, some adjustments can be made to the setting position of the exhaust pump 140, so that it is changed from being set under the side wall 105 between the two reaction chambers to being set between the two reaction chambers. One side of the line connecting the bottom midpoints of two reaction chambers, so that it is easier to connect the isolation member 190 to the top chamber wall and the bottom chamber wall of the reaction chamber. It should be noted that it is not arbitrarily selected on which side of the line connecting the bottom midpoints of the two reaction chambers the exhaust pump 140 is arranged. Because there is an opening valve 180 on the reaction chamber 170, and an opening valve 180' is provided on the reaction chamber 170', the opening valve is arranged between the reaction chamber and the transfer chamber (not shown in the figure), when the opening valve is opened, the reaction chamber in the reaction chamber The completed substrate can be transferred to the transfer chamber through the open valve. When the valve is closed, the reaction chamber is isolated from the transfer chamber. The reaction chamber is in a sealed state, and the reaction chamber can be kept in a vacuum state or filled with reaction gas. Therefore, the exhaust pump 140 can only be arranged on the side opposite to the opening valve 180, so as not to affect the process operation. Basically, if the center point of the two reaction chambers and the center point of the exhaust device in the prior art, these three points are located on a straight line, then in the present invention, the center point of the two reaction chambers and the exhaust pump The center points of 140 then form a triangle.

The isolation member 190 realizes the distance isolation between the first exhaust channel 201 and the second exhaust channel 202, and the channel width of the first exhaust channel 201 and the second exhaust channel 202 also needs to meet certain conditions. Generally speaking, Both the first exhaust passage 201 and the second exhaust passage 202 are passages with a certain length, and the cross-sectional shape of the passage is not limited. The first exhaust passage 201 and the second exhaust passage 202 can be uniform passages, that is, passages The widths of the inlet, the channel outlet, and the channel body are approximately the same, and the sum of the cross-sectional area of the first exhaust channel 201 and the second exhaust channel 202 must be equal to that of the original exhaust channel, that is to say, Although the present invention divides the original exhaust passage into two exhaust passages by setting the isolation member 190, the setting of the isolation member 190 cannot reduce the exhaust volume of the exhaust passage. The first exhaust passage 201 and the second row The exhaust capacity of the gas channel 202 still has to reach the exhaust capacity of the original independent exhaust channel. force. And the sum of the exhaust capacity of the first exhaust passage 201 and the second exhaust passage 202 does not need to exceed the exhaust capacity of the original independent exhaust passage, so it is not necessary to separate the first exhaust passage 201 and the second exhaust passage 202 If the setting is too wide (the cross section is too large), for a circular reaction chamber, it is basically guaranteed that the distance between the channel outer wall of the first exhaust channel 201 and the channel outer wall of the second exhaust channel 202 is less than or equal to a single reaction chamber. The diameter of the cavity is sufficient, and for a rectangular reaction chamber, it is basically guaranteed that the channel outer sidewall of the first exhaust channel 201 (the side wall adjacent to the first exhaust channel 201 and the isolation member 190 is the inner side wall, correspondingly, the distance from the isolation member 190 is the farthest outer wall) and the channel outer wall of the second exhaust passage 202 (similarly, the side wall adjacent to the second exhaust passage 202 and the isolation member 190 is the inner wall, correspondingly, the farthest from the isolation member 190 The distance between the outer walls) should be less than or equal to the diagonal distance of a single reaction chamber.

FIG. 8 is a flow velocity distribution diagram of an exhaust area and an exhaust channel in one of the reaction chambers of the plasma processing equipment in FIG. 6 . Figure 9 is a pressure distribution diagram of the C-C cross-section in Figure 8. It can be seen from Fig. 8 and Fig. 9 that the reaction gas in the reaction chamber enters the exhaust pump from the first exhaust channel and the second exhaust channel on both sides respectively through the blocking and splitting of the isolation part, and the gas at the isolation part The gas flow rate has been slowed down.

Fig. 10 is a flow velocity distribution diagram of the plasma confinement device and the surface of the substrate in one of the reaction chambers of the plasma processing equipment in Fig. 6. It can be seen from Fig. 9 that in the processing area above the substrate, the gas flow rate on the side close to the exhaust channel is close to the gas flow rate on the side away from the exhaust channel, which makes the processing area above the plasma confinement device The uniform gas distribution is beneficial to improve the etching uniformity.

As shown in Figure 11, the gas flow rate in the processing area above the plasma confinement device in the prior art is not uniform, and the difference between the maximum value and the minimum value is very large. The processing equipment greatly equalizes the gas flow rate in the processing area above the plasma confinement device. As can be seen from the graph, the amplitude between the maximum and minimum flow rate is reduced to half that of the previous technology, which better uniforms the substrate surface The gas flow rate is beneficial to improve the etching uniformity.

The invention improves the uniformity of reaction gas distribution on the substrate surface in the plasma processing equipment, improves the etching uniformity of the substrate, and improves the qualified rate of the substrate.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those of ordinary skill in the art after reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended patent application scope.

110: Plasma Confinement Device

133: Electrostatic Chuck

135: Substrate

140: exhaust pump

170: reaction chamber

180: open valve

190: isolation parts

201: The first exhaust channel

202: Second exhaust channel

Claims (8)

A dual-station processor for achieving uniform exhaust, the dual-station processor includes: two adjacently arranged plasma processing chambers, and a shared exhaust pump, in the two plasma processing chambers An opening is arranged below the chamber, and the opening communicates with the exhaust pump. A gas injection device and a base for supporting the substrate are arranged in each of the plasma processing chambers, and the base is surrounded in each of the plasma processing chambers. A plasma confinement device is arranged on the periphery of each plasma confinement device, and an exhaust area is arranged under each plasma confinement device. A plurality of gas channels are arranged on the plasma confinement device for discharging gas to the exhaust area, wherein, in the row An isolation part is arranged between the gas area and the opening, so that there are two exhaust passages between each plasma processing chamber and the exhaust pump, and each exhaust passage has an air inlet and an air outlet. The gas inlet is connected to the exhaust area in the plasma processing chamber, and the gas outlet is connected to the exhaust pump. The dual-station processor realizing uniform exhaust according to claim 1, wherein the exhaust channel is a long straight channel. The dual-station processor for realizing uniform exhaust according to claim 1, wherein two exhaust channels are horizontally arranged between each plasma processing chamber and the exhaust pump. The dual-station processor for uniform exhaust according to claim 1, wherein the minimum distance between the air inlets of the two exhaust channels is greater than or equal to 100mm. The dual-station processor for achieving uniform exhaust according to claim 3, wherein the maximum distance between the inlets of the two exhaust channels is less than or equal to the diameter of the circular plasma processing chamber. The dual-station processor for achieving uniform exhaust according to claim 3, wherein the maximum distance between the inlets of the two exhaust channels is less than or equal to the diagonal length of the rectangular plasma processing chamber. The dual-station processor for achieving uniform exhaust according to claim 1, wherein in the vertical direction, the exhaust pump is arranged below the two plasma processing chambers, and in the horizontal direction, the exhaust pump is connected with the The positional relationship of the two plasma processing chambers satisfies: the central point of the exhaust pump forms a triangle with the central points of the two plasma processing chambers. A plasma processing device for realizing uniform exhaust, wherein the plasma processing device includes at least one double-station processor according to any one of claim 1 to claim 7, each of the double-station processors A gas injection device in the plasma processing chamber is connected to a reactive gas source.