A multi-zone heated plate and lower electrode assembly and plasma processing apparatus

Abstract

The application discloses a multi-zone heating plate, a lower electrode assembly and a plasma processing device. The heating plate comprises a substrate made of insulating material, and a heating layer is arranged in the substrate, and a plurality of independently controllable heating units are arranged in the heating layer. The driving control circuit of the application has simple overall structure, low cost and fast response speed, so that the time for completing one heating cycle in the heating plate is very short, and the temperature fluctuation of each heating unit is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature heating treatment, more particularly to the technical field of multi-zone heating. BACKGROUND

[0002] Multi-zone temperature control technology is widely used in various technical fields, such as chemical industry, biology, pharmaceutical industry and integrated circuit industry, especially in the field of integrated circuit manufacturing. With the continuous reduction of the critical dimension of semiconductor workpieces, such as substrates, and the continuous increase of the size of the substrates, the temperature control accuracy and regional control requirements in the substrate processing process are becoming higher and higher.

[0003] The semiconductor processing technology for integrated circuit manufacturing includes chemical vapor deposition process, plasma processing technology, etc. The etching of the semiconductor substrate is mainly processed by using the plasma processing technology. An important factor affecting the processing effect of the substrate is temperature. With the evolution of the processing technology, the critical dimension is becoming lower and lower, and the requirement for temperature uniformity is becoming higher and higher. The existing technology cannot effectively solve the phenomenon of local temperature non-uniformity in a very small area on the substrate due to the excessively large area of the independently controllable heating zone, which leads to the occurrence of multiple abnormal temperature points on the substrate, the processing effect of the substrate on the corresponding abnormal temperature points cannot be guaranteed, and finally the processing efficiency of the substrate is reduced.

[0004] Therefore, a new multi-zone temperature control heater needs to be developed in the current plasma processing device, which can be integrated in the radio frequency environment in the reaction chamber, especially between the electrostatic chuck and the susceptor, and can optimally reduce the external conductive lines to reduce the requirement for filters. In order to independently drive more heating pieces with fewer driving lines and grounding lines, the existing technology proposes a matrix type heater as shown in Figure 1 The direct current power for heating is connected to the heating pieces on each row driving line in the heating piece matrix through a row of driving switches Si1-Si4, and a row of grounding switches Sr1-Sr4 on the grounding side are connected to the heating pieces on each column driving line in the heating piece matrix. Only when a pair of driving switches and grounding switches (such as Si2 and Sr3) are turned on at the same time, the heating piece R23 corresponding to the pair of switches will be heated. The driving mode using this structure can drive 100 heating pieces with 10+10=20 switches, and the corresponding wiring space and the number of filters are also corresponding to 20 switches. However, this driving mode can only use the point-by-point scanning heating mode, which is slow. If the 100 heating pieces are heated in turn, 100 steps are required. In order to ensure that the heating piece does not cool down too much before completing the heating and the next heating, a very high instantaneous heating current needs to be input when it is the turn to heat, which poses a challenge to the design of the driving circuit.

[0005] Therefore, it is necessary to develop a new multi-zone heating circuit to further reduce the number of driving and grounding lines, and to accelerate the scanning speed to reduce the average heating current. SUMMARY

[0006] Therefore, the multi-zone heating plate, the lower electrode assembly and the plasma processing device are provided to solve the technical problems in the prior art and improve the performance of the semiconductor processing device.

[0007] The multi-zone heating plate comprises a substrate made of insulating material, a heating layer in the substrate, and a plurality of heating units in the heating layer; a plurality of sub-heating zones arranged in a horizontal direction for heating different areas of the substrate, each sub-heating zone comprising at least two heating units, wherein a first heating unit of a first sub-heating zone and a first heating unit of a second sub-heating zone form a first heating unit group, and a second heating unit of the first sub-heating zone and a second heating unit of the second sub-heating zone form a second heating unit group; the first ends of two first heating units in the first heating unit group and the second heating unit group are connected by a first cross-zone connecting line, and the first cross-zone connecting line is connected to a first interface located at the bottom of the substrate; the first ends of two second heating units in the first heating unit group and the second heating unit group are connected by a second cross-zone connecting line, and the second cross-zone connecting line is connected to another first interface located at the bottom of the substrate; the second ends of the first and second heating units of the first and second sub-heating zones are connected to each other by a first area connecting line, and the first area connecting line is connected to a second interface located at the bottom of the substrate.

[0008] Optionally, the heating unit comprises a heating sheet, a plurality of heating sheets of the first sub-heating zone are connected to the second interface through at least one first unidirectional conduction switch, a plurality of heating sheets of the second sub-heating zone are connected to the second interface through at least one second unidirectional conduction switch, and the connection directions of the first and second unidirectional conduction switches are opposite.

[0009] Optionally, the first unidirectional conduction switch is located between the first area connecting line and the second interface.

[0010] Optionally, the heating plate comprises m first interfaces and n second interfaces, the number of heating units whose heating power can be independently controlled is greater than m*n and less than or equal to 2m*n.

[0011] Optionally, each heating unit comprises a heating sheet and a unidirectional conduction switch connected in series, and the connection directions of the unidirectional conduction switches of the first sub-heating zone and the second sub-heating zone are opposite.

[0012] Optionally, the heating plate comprises a plurality of heating zones, and each heating zone comprises the first and second sub-heating zones.

[0013] Optionally, the substrate further comprises an interconnection layer, the interconnection layer is located below the heating layer, the heating units in the heating layer extend downward to the interconnection layer through vertical direction wires, so that the plurality of heating units are interconnected.

[0014] Further, the application also discloses a plasma processing device, comprising:

[0015] a processing cavity, a susceptor located in a lower space in the processing cavity, the susceptor comprising a cooling liquid channel, and a multi-zone heating plate as described above arranged above the susceptor; further comprising a driving device located below the susceptor, the driving device comprising a plurality of power adjustment switches and a plurality of area scanning switches, the plurality of power adjustment switches are respectively electrically connected with a plurality of first interfaces at the bottom of the multi-zone heating plate, and the plurality of area scanning switches are electrically connected with one or more second interfaces in the heating plate.

[0016] Optionally, the plasma processing device further comprises a controller for controlling the plurality of power adjustment switches and the plurality of area scanning switches in the driving device to perform switching operation, wherein the plurality of area scanning switches are sequentially turned on, the controller controls the plurality of power adjustment switches to simultaneously enter a pulse width modulation switching mode, and the on time of the area scanning switch is greater than the switching time of the power adjustment switch.

[0017] Optionally, the driving device is further connected downward to a pulse heating power supply, the pulse heating power supply outputs a heating voltage varying between a positive heating voltage and a negative heating voltage, and the heating voltage is applied to each heating unit in the first and second sub-heating zones through the power adjustment switch / area scanning switch.

[0018] Optionally, the driving device is further connected to a grounding end, and the grounding end is connected to each heating unit in the first and second sub-heating zones through the area scanning switch / power adjustment switch.

[0019] Optionally, the pulse heating power supply outputs a heating voltage through a plurality of output ends, and the heating voltage is applied to each heating unit in the first and second sub-heating zones through the plurality of power adjustment switches, wherein the voltage signals output by each output end are the same.

[0020] Further, the application also discloses a plasma processing device, comprising:

[0021] The processing cavity, the base in the lower space of the processing cavity, the base includes the cooling liquid passage, the multi-zone heating plate is arranged above the base; further comprising a drive device is located below the base, the drive device includes a plurality of power adjustment switches, the plurality of power adjustment switches are respectively connected with a plurality of first interfaces on the bottom of the multi-zone heating plate, a plurality of output terminals of a pulse heating power supply are connected with one or more second interfaces in the heating plate, wherein when the output voltage of one of the output terminals is switched between the positive heating voltage and the negative heating voltage, the output voltage of at least one of the other output terminals is maintained at zero voltage.

[0022] Further, the application also discloses a plasma processing device, comprising:

[0023] The processing cavity, the base in the lower space of the processing cavity, the base includes the cooling liquid passage, the multi-zone heating plate is arranged above the base; further comprising a drive device is located below the base, the drive device includes a plurality of power adjustment switches, the plurality of power adjustment switches are respectively connected with a plurality of first interfaces on the bottom of the multi-zone heating plate, a plurality of output terminals of a pulse heating power supply are connected with one or more second interfaces in the heating plate, wherein when the output voltage of one of the output terminals is switched between the positive heating voltage and the negative heating voltage, the output voltage of at least one of the other output terminals is maintained at zero voltage.

[0024] Optionally, the plasma processing device is also provided with a pulse heating power supply, the pulse heating power supply includes a plurality of output terminals, each output terminal outputs a heating voltage to one of the plurality of power adjustment switches, wherein the heating voltage changes between the positive heating voltage and the negative heating voltage.

[0025] Further, the application also discloses a lower electrode assembly, comprising: a base made of conductive material, the base includes a cooling liquid passage, a multi-zone heating plate is arranged above the base, the multi-zone heating plate includes: a substrate made of insulating material, the substrate includes a plurality of heating units, each heating unit is used for heating different areas of the substrate; the plurality of heating units in the substrate form:

[0026] a plurality of cross-zone heating unit groups, each of which comprises a plurality of heating units, and the heating units in each of the cross-zone heating unit groups are connected by a cross-zone connecting line, each of which is in communication with a first driving control line below, for receiving a first electric signal from below;

[0027] a plurality of zone heating unit groups, each of which comprises a plurality of heating units adjacent to each other, and all the heating units in each of the zone heating unit groups are connected by a zone connecting line, each of which is in communication with a second driving control line below, for receiving a second electric signal from below;

[0028] The second electric signal makes the plurality of zone heating unit groups enter heating stages in sequence, and a plurality of the first electric signals are used to control the heating power of each heating unit in the zone heating unit group in the heating stage, so as to finally complete the heating of the entire substrate.

[0029] Optionally, each of the zone heating unit groups covers different zones of the substrate, and each heating unit in the zone heating unit group is adjacent to the heating units in other groups, forming a matrix of heating units in multiple rows and multiple columns.

[0030] Further, the application discloses a plasma processing device, comprising:

[0031] a processing cavity, the lower part of the processing cavity comprising the lower electrode assembly described above, and at least one RF power source connected to the lower electrode assembly; the lower part of the lower electrode assembly comprising a plurality of power adjustment switches and / or a plurality of zone scanning switches.

[0032] Optionally, one of the plurality of first driving control lines or second driving control lines is connected to a pulse heating power source below, the pulse heating power source being used to output a heating voltage, the heating voltage varying between a positive heating voltage and a negative heating voltage, and a plurality of unidirectional conduction switches with different conduction directions being connected in series in the plurality of heating unit groups.

[0033] The application has the following advantages:

[0034] The present application realizes the sequential heating of each heating area by sequentially opening a plurality of area scanning switches, and realizes the automatic division of a plurality of heating units in one heating area into two sub-heating areas by the combination of a pulse power supply and two diodes, and finally realizes the independent heating of the same number of areas by using fewer driving lines than the prior art. The pulse power supply outputs a relatively stable heating voltage, which is then controlled by PWM switching control through a power adjustment switch to control the heating power output to each heating unit. This driving structure can quickly control the heating power of the heating units in the same sub-heating area, so that the complete heating cycle of each heating unit (total number 196) in a heating plate can be completed in less than 300 ms, and the heating time of each sub-heating area is about 20 ms. The pulse power supply in the present application has a simple structure, so the cost and space occupation are very limited, and the multiple driving switches and area scanning switches in the driving unit only perform PWM operation, so they are also easy to control and drive. Therefore, the driving control circuit of the present application has a simple overall structure, low cost and fast response speed, so that the time for completing a heating cycle in the heating plate is very short, and the temperature fluctuation of each heating unit is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed in the embodiments of the present application. The drawings in the following description are only part of the embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of the drawings provided by the present application.

[0036] Figure 1 It is a schematic diagram of a matrix heater structure of a prior art;

[0037] Figure 2 It is a schematic diagram of a partition scanning heater structure of the present application;

[0038] Figure 3a It is a partition diagram of the partition scanning heater of the present application;

[0039] Figure 3b It is a schematic diagram of the electrical connection structure of each heating sheet in the heater of the present application;

[0040] Figure 4 It is a schematic diagram of the layering and interconnection structure in the heater of the present application;

[0041] Figure 5 It is a schematic diagram of the structure of a plasma processing device using the partition scanning heater of the present application;

[0042] Figure 6 It is a schematic diagram of another partition arrangement structure of the partition scanning heater of the present application;

[0043] Figure 7 Another embodiment of the zonal scanning heater of the present application is shown in the figure;

[0044] Figure 8 Another embodiment of the zonal scanning heater of the present application is shown in the figure;

[0045] Figure 9 Another embodiment of the zonal scanning heater of the present application is shown in the figure. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0047] In order to clearly describe the technical solutions of the present application, a plurality of concepts are used, and the main concepts are explained as follows:

[0048] Heating unit, heating sheet or combination of heating sheet and diode;

[0049] Sub-heating zone, the substrate is divided in physical space, each sub-heating zone is used for heating different areas of the substrate, and each sub-heating zone includes two or more heating units;

[0050] Heating unit group, including cross-zone heating unit group and area heating unit group, a heating unit in a plurality of sub-heating zones is connected to form a cross-zone heating unit group through the same cross-zone connecting line;

[0051] Heating zone: two sub-heating zones with the same area connecting line and area scanning switch are located in the same heating zone, and the heating units in the heating zone form an area heating unit group.

[0052] Cross-zone connecting line: connecting line for connecting a plurality of heating units of the same cross-zone heating unit group, each cross-zone connecting line can be connected with a power adjustment switch.

[0053] Area connecting line: connecting line for connecting the second ends of a plurality of heating units of two sub-heating zones in the same heating zone, each area connecting line can be connected with an area scanning switch;

[0054] First driving control line: used for realizing the connection between the cross-zone connecting line and the power adjustment switch and the heating power supply or ground.

[0055] Second driving control line: used for realizing the connection between the area connecting line and the area scanning switch and the heating power supply or ground.

[0056] The present application discloses a multi-zone heating device, such as Figure 2 The figure shows the heater control and driving circuit of the present application. It includes 12 heating pieces, each of which is arranged in a roughly horizontal direction in the heater plate, each of which is responsible for heating a small area of the wafer region above it. In order to facilitate the description of its circuit structure, the figure Figure 2 The main description is its electrical connection structure, which does not represent the actual spatial position.

[0057] The present application includes a first heating piece group S1A1-S1A3, each of which can be electrically connected to a first diode D1 to form a first heating unit group, and a second heating piece group S1B1-S1B3, each of which is electrically connected to a second diode D2 to form a second heating unit group. The orientations of diodes D1 and D2 are opposite, so that the current directions of the first and second heating piece groups are opposite when heating. Each heating piece can form a heating unit, or a heating piece and a diode connected in series can form a heating unit. The above two heating pieces and the diode connected in series form the first and second heating unit groups, and the first and second heating unit groups correspond to two sub-heating zones. One end of each heating unit in the two heating unit groups is connected to a common area connection line R1, and the area connection line R1 is connected downward to the area scanning switch G1 through a vertical downward driving control line V11 and connected to the ground. The present application also includes a third heating unit group (S2A1-S2A3) and a fourth heating unit group (S2B1-S2B3) which are the same as the two heating unit groups on the right side of the figure. One end of each heating unit of the two heating unit groups is connected to a common area connection line R2, and the area connection line R2 is connected to the area scanning switch G2 through a vertical downward driving control line V12 and connected to the ground.

[0058] Figure 3a 、 3bThe spatial area division and position relationship of each heating sheet in the heater is shown, wherein the heater comprises a first heating zone S1 and a first sub-heating zone S1A and a second sub-heating zone S1B in the first heating zone S1, a second heating zone S2 and a third sub-heating zone S2A and a fourth sub-heating zone S2B in the second heating zone S2. The driving ends of four heating units S1A1, S1B1, S2A1 and S2B1 distributed in the four sub-heating zones are connected to each other through a common first cross-zone connecting line L1 to form a first cross-zone heating unit group, and the cross-zone connecting line L1 is connected to a first driving switch K1 through a vertically downward driving control line V21 and connected to a driving voltage output port of a pulse heating power supply. Similarly, the driving ends of four heating units S1A2, S1B2, S2A2 and S2B2 in the four sub-heating zones are connected to each other through a common second cross-zone connecting line L2 to form a second cross-zone heating unit group, and the second cross-zone connecting line L2 is connected to a second driving switch K2 through a vertically downward driving control line V22 and connected to a second driving voltage output port of the pulse heating power supply. The driving ends of four heating units S1A3, S1B3, S2A3 and S2B3 in the four sub-heating zones are connected to each other through a common third cross-zone connecting line L3 to form a third cross-zone heating unit group, and the third cross-zone connecting line L3 is connected to a third driving switch K3 through a vertically downward driving control line V23 and connected to a third driving voltage output port of the pulse heating power supply. The cross-zone heating unit group defined in the present application can be formed by heating units corresponding in position in each sub-heating zone, or formed by heating units not corresponding in position in each sub-heating zone, for example, when the spatial shapes of different sub-heating zones are quite different, the position arrangement of the heating units in each sub-heating zone is different in different areas, and it is difficult to realize one-to-one correspondence of the position relationship, therefore, as long as the plurality of heating units connected to each other through the same cross-zone connecting line belong to the same cross-zone heating unit group defined in the present application.

[0059] The driving voltage output by the pulse heating power supply in the present application is not a stable direct current power supply in the conventional technology, but a pulse heating power supply alternating between a positive direct current heating voltage (+V) and a negative direct current heating voltage (-V), wherein the heating voltage can be selected as 24V or other suitable heating voltage.

[0060] The working process of the heater of the present application is described in the following stages:

[0061] Stage 1: when the voltage output by the pulse heating power supply is negative voltage (Ta), Figure 2The middle and lower area scanning switch Gl is turned on, and G2 is turned off. At this time, the two groups of heating units corresponding to the left S2 area become electrically floating, and there is no conduction loop, so there is no possibility of generating heating current. Only the two groups of heating units in the right S1 area are connected between the output voltage and the ground. However, due to the existence of diodes D1 and D2 in series in each heating unit, only the heating pieces S1A1-S1A3 in the first sub-heating area can be heated. At the same time, the first to third driving switches K1-K3 are pulse width modulation driven (PWM), so that the conduction duty cycle of each driving switch can be independently adjusted, so that the actual heating current delivered to the heating pieces S1A1-S1A3 can also be independently adjusted.

[0062] Stage 2: After the heating of the multiple heating pieces in stage 1 is completed, the pulse heating power output voltage is converted to a positive voltage (Tb). Due to the existence of diodes D1 and D2 in series in each heating unit, only the heating pieces S1B1-S1B3 in the second sub-heating area S1B can be heated. The first to third driving switches K1-K3 adjust the duty cycle data according to the instructions given by the controller, so that the average heating current in the second heating piece group S1B1-S1B3 can be independently adjusted according to the duty cycle.

[0063] Stage 3: After the heating of the multiple heating pieces in stage 2 is completed, the area scanning switch Gl is turned off, and the switch G2 is turned on. At this time, the two groups of heating units corresponding to the right S1 area become electrically floating and stop heating. The pulse heating power output voltage is converted to a negative voltage again. The heating units in the sub-heating area S2B in the second heating area S2 are prevented from heating due to the blocking of diode D2. The heating pieces S2A1-S2A3 in the sub-heating area S2A can be heated. The specific heating power of each heating piece is adjusted by the opening duty cycle of switches S1-S3.

[0064] Stage 4: After the heating of the third grounding sub-heating area S2A is completed, the pulse heating power output voltage is converted to a positive voltage, and the sub-heating area S2A stops heating. The heating pieces S2B1-S2B3 in the sub-heating area S2B can be heated. The heating power value of each heating piece can be adjusted by adjusting the opening duty cycle of the driving switches S1-S3.

[0065] The above four stages can be cycled, so that the entire heater can achieve independent control of each of the 12 heating pieces through only four steps, and the number of drive lines (in series with drive switches K1-K3) and area connection lines (in series with area scanning switches G1, G2) required is only 3+2=5. In the case of lower process temperature uniformity requirements, the number of independently controlled heating units can be reduced, and multiple area scanning switches such as G1, G2 can be turned on at the same time, at which time multiple heating units in the two sub-heating zones S1A and S2A will be heated at the same time, and then the corresponding heating units in S1B and S2B will be heated in the next stage. According to process requirements, the heating method of heating one by one in a single sub-heating zone can be performed in part of the time period, and the control method of simultaneously heating multiple sub-heating zones in a part of the temperature requirement low area, which can shorten the number of steps of the partition scanning, and speed up the response speed of temperature adjustment, also belongs to the embodiments of the present application.

[0066] The above heater circuit can be further expanded, such as expanded to more sub-heating zones or each sub-heating zone can include more heating units. The heater can additionally provide two heating zones, each including two sub-heating zones. The number of heating pieces in each sub-heating zone is increased to 5, and the number of corresponding drive switches is also increased to 5 corresponding to the maximum number of heating pieces in the sub-heating zone, and the number of area scanning switches is increased to 4 corresponding to the number of heating zones. The expanded heater forms 5X4X2=40 independent heating units, but the number of drive lines and ground lines is only 5+4=9. Using the same principle, when the heater circuit is expanded to 10 heating zones (20 sub-heating zones) and each heating zone includes 10 independently driven heating units, only 20 lines are needed to achieve independent heating of 200 zones. The matrix connection structure in the prior art requires 28 (14X14) lines to achieve a similar effect. Therefore, the present application can further reduce the number of drive and ground lines, and since the present application simultaneously heats multiple heating pieces in the entire sub-heating zone, the number of steps to complete a heating cycle is much smaller than the circuit structure that needs to be scanned point by point in the prior art, so the peak current flowing through the heating piece can also be much smaller than the comparative document, and the hardware requirements for each switch can also be greatly reduced. For example, by reducing the number of scanned sub-heating zones, the present application can make the time of a heating cycle less than 400ms or even less than 300ms, so that the short cycle time can stably maintain the temperature of each heating zone at an optimal value, and the temperature of part of the heating pieces will not deviate due to too long interval between two heating times.

[0067] The number of heating pieces in the extended heating area in the present application can also be adjusted according to actual needs, for example, in the local area of the heating plate, there are only two heating units in one sub-heating area in the extended third heating area, which is less than the number of heating units in the surrounding other sub-heating areas. Or two heating pieces can be connected in parallel and connected in series with a diode to form a multi-heating piece heating unit. Such two heating pieces have the same heating voltage, but the relative heating power of the two cannot be independently adjusted.

[0068] Figure 4 The layered structure of the sub-area scanning heater of the present application is shown, in which a plurality of heating pieces are located in the upper insulating material layer 40, and the lower insulating material layer 42 serves as an interconnection layer. The second end of the upper heating piece S1A1 and the second end of the heating piece S2A1 are extended to the lower interconnection layer through vertical direction wires, and the two are electrically connected to each other through horizontal direction interconnection wires and converge to the bottom interface P1. The heating pieces S1B1, S2B1 can also be connected through the above-mentioned interconnection wires and converge to the interface P1. The interface P1 of the bottom surface of the heater can be connected downward to electronic components and devices that need to work in a low temperature environment, such as driving switch K1, through an electrical connection structure (soldered wires or inserted plugs, etc.). The interface P1 and the heating pieces S1A1, S2A1 are connected in series with a first diode D1, and the heating pieces S1B1, S2B1 are also connected in series with a diode D2, wherein the connection direction of the diodes D1, D2 is opposite, so that the heating pieces connected with the diodes D1, D2 have opposite current directions. Figure 3a 、 Figure 3b and Figure 4 The circuit of 12 heating units in 4 sub-heating areas for time multiplexing driving by three driving switches K1-K3 is shown in FIG. 4. The first driving heating unit group (S1A1, S2A1, S1B1, S2B1) is connected by the cross-area connection wire L1 and then driven by K1 to realize adjustable heating power. The four heating units (S1A2, S2A2, S1B2, S2B2) in the second position in the heating area form the second driving heating unit group, which are also electrically connected to each other through the wire L2 and converge to an interface, and each heating piece is also connected to a driving switch K2 or K3 respectively. Figure 2The diodes D1 / D2 with different conduction directions are finally connected through the cross-zone connection line L2 and then driven by K2 to adjust the heating power. Similarly, the four heating pieces (S1A3, S2A3, S1B3, S2B3) in the third position of the four heating zones constitute the third driving heating unit group, which are also electrically connected to each other through the lead L3 and then gathered to an interface P1. Each heating piece is also connected to, for example, diodes D1 / D2 with different conduction directions. The diodes D1 / D2 can be located in the insulating interconnection layer 42 below the insulating material layer 40 where the heating pieces are located, and are preferably located on the bottom surface of the insulating interconnection layer 42, so that the diodes are closer to the lower cold base, and the temperature of the diodes D1 / D2 is maintained within an acceptable range. Alternatively, the diodes D1 / D2 can also be embedded in the groove on the upper surface of the base to further control the temperature of the diodes from overheating.

[0069] The second end of each heating unit of the two heating sub-zones (S1A, S1B) of the first heating zone is connected to the external ground terminal through the aggregated zone connection R1 and the zone scanning switch G1. The second end of each heating unit of the two heating sub-zones (S2A, S2B) of the second heating zone is aggregated through the zone connection line R2 and then connected to the external ground terminal through the zone scanning switch G2.

[0070] Figure 5The application discloses a plasma processing device applied to a heater, wherein the plasma processing device comprises a processing cavity 100 capable of achieving air tightness, an air inlet device 20 is arranged at the top of the processing cavity, and a lower electrode assembly is arranged at the bottom of the processing cavity, the lower electrode assembly comprises a base 10 which is usually made of metal materials such as aluminum. The base 10 is provided with a cooling liquid channel 8 which is communicated with an external cooling liquid source, so as to control the temperature of the base. At least one radio frequency power supply supplies radio frequency power to the base 10, so as to control the ion energy incident to a wafer. The upper surface of the base 10 is connected with a disc-shaped heater 12 through a bonding layer 11, a large number of heating pieces 121 extending in the horizontal direction are arranged in the heater 12, and the temperature of the wafer corresponding to each heating piece can be finely adjusted by independently controlling the heating power of each heating piece. An electrostatic chuck 13 is further arranged above the heater 12, the electrostatic chuck comprises an electrostatic adsorption electrode which is connected to an external high-voltage direct current source. An edge ring 14 surrounds the heater 12 and the electrostatic chuck 13, so as to control the plasma and electric field distribution around the wafer to be processed. The bottom of the heater 12 comprises a plurality of interfaces, a plurality of driving control lines extending in the vertical direction are arranged at each interface, the driving control lines pass through the through holes arranged on the base downwards, and are electrically connected to a driving control circuit arranged below the base and used for driving and controlling the upper heating unit. Part of the driving control lines are used as power supply lines 35, and the other part of the driving control lines are used as grounding lines 37. The power supply lines 35 are connected to a driving unit 33a downwards, a plurality of driving switches K1, K2 and K3 are arranged in the driving unit 33a, and the heating power proportion of the heating pieces in the upper heater can be controlled by controlling the switch duty cycle of each driving switch. A filter 32a is further arranged below the driving power supply 33a, so that the radio frequency power existing in the processing cavity 100 is blocked in the space above the filter 32a and cannot leak downwards to the outside of the processing cavity. The filter 32a is connected to a pulse power supply 30 downwards, wherein the pulse power supply is used for outputting a driving voltage which changes between a positive voltage (+V) and a negative voltage (-V), the voltage values of the positive voltage and the negative voltage can be adjusted according to requirements, and the duration of the two stages can also be adjusted according to requirements, so as to assist in adjusting the average heating power of each sub-heating area above. The grounding lines 37 are connected to a driving unit 33b, a plurality of regional scanning switches G1 and G2 are arranged in the driving unit 33b and are used for selective grounding, the driving unit 33b is connected to a grounding end outside the reaction cavity through a wire and a filter 32b. In addition to the driving units 33a and 33b, the driving control circuit further comprises at least one controller which is located below the driving units, is connected with each switch (K1-K3, G1 and G2) one by one through a plurality of control lines and outputs a control signal, so as to drive the above-mentioned switches to be turned on in turn or simultaneously according to a control strategy.The controller outputs a second control signal to sequentially open the area scanning switch (G1, G2), and outputs a first control signal to simultaneously drive the driving switch (K1-K3) according to the duty cycle data.

[0071] The plasma processing cavity further comprises an isolation wall 17, so that the space above the isolation wall 17 is a vacuum processing space during the process, and the gas in the vacuum processing space is exhausted. The space below the isolation wall 17 is an atmospheric environment, but is still in the radio frequency power radiation area, and is isolated from the radio frequency power below the filter. The pulsed power supply 30 in the present application can also be arranged inside the internal space of the reaction processing cavity 100, upstream of the filter 32a. A direct current power supply is arranged outside the processing cavity, and the voltage output by the direct current power supply is transmitted to the pulsed power supply 30 upstream of the filter 32a after being filtered by the filter 32a. The switch and circuit inside the pulsed power supply convert the received voltage into a pulsed voltage required to drive the upper heater, and then transmit it to the driving unit 33a. The switch in the driving unit 33a needs to be PWM controlled to adjust the heating power of the corresponding heating sheet above, so high-frequency (Khz) switching operation is required, which generates high heat. The driving unit 33b only needs to be switched once when the heated area needs to be switched, so the heat generated is low. Therefore, the driving unit 33a can be placed in the lower space outside the reaction cavity to facilitate heat dissipation, and the driving unit 33b can be placed inside or outside the reaction cavity.

[0072] Figure 5 The power supply line 35 or the ground line 37 in the above embodiment can be a single wire as shown in Figure 4 Each interface P1 passes through a passage provided in the lower adhesive layer 11 and the base 10 to the lower driving unit 33a, 33b through a respective wire. The multiple interfaces can extend multiple wires which are insulated from each other and then integrated into a wire bundle, and then extended downward through a passage.

[0073] Figure 2 Fig. 1, 2 and 3 show a method for partitioning heating sheets in a heater, Figure 6Other partition methods and heating sequences are shown. Among them, the sub-partitions can be fan-shaped division, and then each fan-shaped area is heated in the rotating direction, or two fan-shaped areas are heated in pairs; or the heating pieces are distributed in multiple annular areas, and are heated in the radial direction; the heating pieces H1a, H1b, H2a, H2b are alternately and spaced to form multiple square sub-heating areas, and the multiple sub-heating areas are arranged in a matrix form, and the heating pieces H1a, H1b, H2a, H2b in each sub-heating area are heated in turn. The heating area of the present application can also be a combination of multiple patterns, or even an arbitrary pattern, as long as multiple heating areas are finally combined into a circular heating area corresponding to the wafer. Figure 2 In the embodiment shown, the first heating area S1 is used to heat the outer annular area, and 24 heating units can be arranged in the area S1, which are driven by 12 power adjustment switches at the same time. The second heating area S2 is located in the inner annular area, and only 18 heating units are arranged, which are driven by 9 power adjustment switches. At this time, the cross-area interconnection lines L1, L2, L3 realizing the interconnection of the same group of heating units are provided, and part of the cross-area interconnection lines are only connected to the heating units in the area S1 and are not connected to the area S2.

[0074] Figure 7 Another embodiment of the heater driving circuit of the present application is shown, which is basically the same as the structure of the heater circuit shown in Figure 2 The difference is that the multiple output ends of the pulse heating power supply are directly connected to the second ends of the multiple heater unit groups above, without the need to set the switches (G1 / G2) for performing area scanning, and the first ends of the multiple heater units are connected to the ground end through the driving switches K1-K3. Among them, the two output ends of the pulse heating power supply are mutually staggered to output the driving voltage, and the voltage of the driving voltage 2 is zero in the Tc1 time period, and the driving voltage 1 is pulsed to switch to drive the two heating sub-areas in the right heating area to heat. Then in the Tc2 time period, the output voltage of the driving voltage 1 is zero, and the driving voltage 2 is pulsed to switch to drive the two sub-areas on the left to heat in turn. Or the two output ends of the pulse heating power supply are connected to the two heating areas above through two area scanning switches connected in series respectively, and each output end outputs the same pulse voltage signal, and the heating area to be driven is selected by the opening or closing of the two area scanning switches, so as to realize the heating of each heating piece in the multiple sub-heating areas in turn.

[0075] Figure 8 Another embodiment of the heater driving circuit of the present application is shown, which is basically the same as the structure of the heater circuit shown in Figure 7The structures of the shown heater circuits are basically the same, the difference is that the second ends of the three heating pieces in each sub-heating zone are converged, and each sub-heating zone is connected to two output terminals of the pulse heating power supply through a common diode D10a, D10b, D20a, D20b respectively. Such a driving circuit structure can also achieve the same function, and is a variant embodiment of the present application. Figure 7

[0076] Figure 9 Another embodiment of the heater driving circuit of the present application is shown, which has basically the same structure as the Figure 8 shown heater circuit, the difference is that the pulse heating power supply is arranged upstream of the heating unit, and each heating unit is connected to the pulse heating power supply through a driving switch K1 / K2 / K3. The wires of the second ends of the three heating units in the first sub-heating zone in the right heating zone are converged to port Pa, and then connected to the area scanning switch G1 and the ground below through a common diode D10a. The wires of the second ends of the three heating units in the second sub-heating zone are converged to port Pb, and then connected to the area scanning switch G1 and the ground below through a common diode D10b. The connection mode of the left heating zone is the same as the right side.

[0077] The above embodiments described in the present application disclose that the sequential heating of each heating zone is realized by sequentially opening the multiple area scanning switches, and at the same time, the multiple heating units in one heating zone are automatically divided into two sub-heating zones by the combination of the pulse power supply and the two diodes, finally realizing the independent heating of the same number of regions with fewer driving lines than the prior art. The relatively stable heating voltage output by the pulse power supply is controlled by the PWM switch control through the power adjustment switch, realizing the heating power control of each heating unit. This driving structure can quickly realize the heating power control of the heating units in the same sub-heating zone, so that the complete heating cycle of each heating unit (total number 196) in a heating plate can be completed in less than 300ms, and the heating time of each sub-heating zone is about 20ms. The pulse power supply in the present application has a simple structure, so the cost and space occupation are very limited, and the multiple driving switches and area scanning switches in the driving unit only perform PWM operation, so they are also easy to control and drive. Therefore, the overall structure of the driving control circuit of the present application is simple, low in cost and fast in response, so that the time for completing a heating cycle in the heating plate is very short, and the temperature fluctuation of each heating unit is reduced.

[0078] ​The diode in the present application can be replaced by other switches that can realize unidirectional conduction, such as a MOSFET with automatic control of its switch according to the difference in voltage across the two terminals, such as the LTC4359 microchip provided by the Analog device company, which can be used to drive a MOSFET with a conduction impedance much smaller than the diode to realize unidirectional conduction in a controlled manner. Therefore, any switching device that can realize unidirectional conduction can be used in the present application and become a component of the multi-zone heating circuit structure of the present application.

[0079] The partition priority selection in the present application gathers the heating units of the same sub-heating zone together, which can simplify the wiring. At the same time, when entering the heating stage, some positions that are sensitive to temperature, such as the helium jet on the electrostatic chuck and the position corresponding to the wafer lifting needle, require precise fine tuning of the temperature. The heating units corresponding to these positions that need fine tuning are preferably surrounded by other heating units in a sub-heating zone, avoiding being located at the junction of two heating zones. Alternatively, the heating zone of the present application includes at least multiple rows and multiple columns of heating units to place the key heating zone in a sub-heating zone. If multiple heating units of the key position are located in two sub-heating zones, the heating current of these heating units needs to pass through the area connection lines (R1, R2) and area scanning switches (G1, G2) located in two different sub-heating zones, different diodes (D1, D2) through two heating steps, which will inevitably cause temperature errors due to device parameter errors. This error cannot be solved in batches and can only be solved by individually adjusting the heating power parameters of each plasma processor, which is relatively high in cost. The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-zone hot plate characterized by, The application relates to a multi-zone heating plate, comprising: a substrate made of insulating material, the substrate comprising a heating layer, the heating layer comprising a plurality of heating units; a plurality of sub-heating zones for heating different areas of the substrate, each sub-heating zone comprising at least two heating units, wherein a first heating unit of a first sub-heating zone and a first heating unit of a second sub-heating zone form a first heating unit group, and a second heating unit of the first sub-heating zone and a second heating unit of the second sub-heating zone form a second heating unit group; two first heating units in the first heating unit group and the second heating unit group are connected by a first cross-zone connecting line, and the first cross-zone connecting line is connected to a first interface located at the bottom of the substrate; two second heating units in the first heating unit group and the second heating unit group are connected by a second cross-zone connecting line, and the second cross-zone connecting line is connected to another first interface located at the bottom of the substrate; the second ends of the first and second heating units of the first and second sub-heating zones are connected by a first area connecting line, and the first area connecting line is connected to a second interface located at the bottom of the substrate; the first interfaces at the bottom of the substrate are used for being connected to a first one-way conducting switch and a second one-way conducting switch, wherein the connection directions of the first and second one-way conducting switches are opposite; the second interface or the first interfaces are used for receiving an external pulse heating voltage, and the pulse heating voltage changes between a positive heating voltage and a negative heating voltage.

2. The multi-zone hot plate of claim 1, wherein, The heating units comprise heating pieces, the heating pieces of the first sub-heating zone are connected to the second interface by at least one first one-way conducting switch, the heating pieces of the second sub-heating zone are connected to the second interface by at least one second one-way conducting switch, and the connection directions of the first and second one-way conducting switches are opposite.

3. The multi-zone hot plate of claim 2, wherein, The first one-way conducting switch is located between the first area connecting line and the second interface.

4. The multi-zone hot plate of claim 1, wherein, The heating plate comprises m first interfaces and n second interfaces, the number of heating units with independently controllable heating power is greater than m*n and less than or equal to 2m*n.

5. The multi-zone hot plate of claim 1, wherein, Each of the heating units comprises heating pieces and one-way conducting switches connected in series, and the connection directions of the one-way conducting switches of the first sub-heating zone and the second sub-heating zone are opposite.

6. The multi-zone hot plate of claim 1, wherein, The heating plate comprises a plurality of heating zones, and each of the heating zones comprises the first and second sub-heating zones.

7. The multi-zone hot plate of claim 1, wherein, The substrate further comprises an interconnection layer located below the heating layer, and the heating units in the heating layer extend downward to the interconnection layer through vertical conductive lines, so that the plurality of heating units are interconnected.

8. A plasma processing device, comprising: a processing chamber, a susceptor located in a lower space in the processing chamber, the susceptor comprising a cooling liquid channel, and a multi-zone heating plate according to any one of claims 1 to 7 arranged above the susceptor, and further comprising a driving device located below the susceptor, the driving device comprising a plurality of power adjustment switches and a plurality of area scanning switches, the plurality of power adjustment switches being electrically connected to the first interfaces at the bottom of the multi-zone heating plate respectively, and the plurality of area scanning switches being electrically connected to one or more second interfaces in the heating plate.

9. The plasma processing apparatus of claim 8, wherein, The driving device further comprises a controller for controlling the switching of the plurality of power adjustment switches and the plurality of area scanning switches, wherein the plurality of area scanning switches are sequentially switched on, and the controller controls the plurality of power adjustment switches to enter the pulse width modulation switching mode at the same time, and the on time of the area scanning switches is greater than the switching time of the power adjustment switches.

10. The plasma processing apparatus of claim 8, wherein the first and second electrodes are disposed in a parallel relationship. The driving device is further connected to a pulse heating power supply, and the pulse heating power supply outputs a heating voltage, which is applied to each heating unit of the first and second sub-heating areas through the power adjustment switches / area scanning switches.

11. The plasma processing apparatus of claim 10, wherein the first and second electrodes are disposed in a parallel relationship. The driving device is further connected to a ground terminal, and the ground terminal is connected to each heating unit of the first and second sub-heating areas through the area scanning switches / power adjustment switches.

12. The plasma processing apparatus of claim 10, wherein, The pulse heating power supply outputs a heating voltage through a plurality of output terminals, and the heating voltage is applied to each heating unit of the first and second sub-heating areas through the plurality of power adjustment switches, wherein the voltage signals output by each output terminal are the same.

13. A plasma processing device, comprising: a processing chamber, a base located in a lower space in the processing chamber, the base comprising a cooling liquid channel therein, and a multi-zone heating plate arranged above the base, a driving device arranged below the base, the driving device comprising a plurality of power adjustment switches, the plurality of power adjustment switches being respectively electrically connected to a plurality of first interfaces at the bottom of the multi-zone heating plate, and a plurality of output terminals of a pulse heating power supply being electrically connected to one or more second interfaces in the heating plate, wherein when the voltage output by one of the output terminals is switched between a positive heating voltage and a negative heating voltage, the voltage output by at least one other of the output terminals is maintained at zero voltage.

14. A plasma processing device, comprising: a processing chamber, a base located in a lower space in the processing chamber, the base comprising a cooling liquid channel therein, and a multi-zone heating plate arranged above the base, the heating plate comprising a plurality of heating units arranged in a horizontal direction, and a driving device arranged below the heating plate, the driving device comprising a plurality of power adjustment switches and a plurality of area scanning switches; the heating plate comprising a plurality of heating zones, each heating zone comprising a first sub-heating area and a second sub-heating area, and each sub-heating area comprising at least three heating units, wherein the first, second, and third heating units of the first sub-heating area correspond to the first, second, and third heating units of the second sub-heating area, forming a heating unit group; the first ends of the heating units in each heating unit group are connected to each other through a cross-zone connection line corresponding to the heating unit group, and each cross-zone connection line is connected to one of the plurality of power adjustment switches; the second ends of each heating unit of the two sub-heating areas in the same heating zone are connected to each other through an area connection line, and each area connection line is connected to an area scanning switch; the first sub-heating area is provided with a first unidirectional conduction switch, and the second sub-heating area is provided with a second unidirectional conduction switch, wherein the connection directions of the first and second unidirectional conduction switches are opposite; and a pulse heating power supply is used to output a heating voltage to the driving device.

15. The plasma processing apparatus of claim 14, wherein the pulsed heating power supply includes a plurality of outputs, each output outputting a heating voltage to one of the plurality of power adjustment switches, wherein the heating voltage varies between a positive heating voltage and a negative heating voltage.

16. A lower electrode assembly, comprising: a base of electrically conductive material, the base including a cooling fluid passage therein, the base having a multi-zone heating plate disposed thereover, the multi-zone heating plate including: a substrate of electrically insulating material, the substrate including a plurality of heating elements therein, each heating element for heating a different region of the substrate; the plurality of heating elements in the substrate being grouped into: a plurality of cross-zone heating element groups, each cross-zone heating element group including a plurality of heating elements therein, and each heating element in each cross-zone heating element group being connected by a cross-zone connection line, each cross-zone connection line being in communication with a first drive control line below for receiving a first electrical signal therefrom, the plurality of cross-zone heating element groups having a plurality of unidirectional conduction switches connected in series thereon, the first electrical signal being a pulsed heating voltage, the pulsed heating voltage varying between a positive heating voltage and a negative heating voltage; a plurality of zone heating element groups, each zone heating element group including a plurality of heating elements therein that are adjacent to one another, and all of the heating elements in each zone heating element group being connected by a zone connection line, each zone connection line being in communication with a second drive control line below for receiving a second electrical signal therefrom; the second electrical signal causing the plurality of zone heating element groups to enter a heating phase in sequence, and a plurality of the first electrical signals for controlling a heating power of each heating element in the zone heating element group in the heating phase to ultimately complete heating of the entire substrate.

17. The lower electrode assembly of claim 16, wherein, each zone heating element group covering a different region of the substrate, and each heating element in each zone heating element group being adjacent to heating elements in other groups to form a matrix of heating elements in rows and columns.

18. A plasma processing apparatus, comprising: a processing chamber, the processing chamber including the lower electrode assembly of any one of claims 16 or 17 in a lower portion thereof, at least one RF power source connected to the lower electrode assembly; the lower electrode assembly having a plurality of power adjustment switches and / or a plurality of zone scanning switches disposed below thereof.

19. The plasma processing apparatus of claim 18, wherein the gas distribution assembly comprises a plurality of gas distribution elements, each of the plurality of gas distribution elements being configured to supply a different gas to the processing volume. one of the first drive control lines or the second drive control lines being connected to a pulsed heating power supply below, the pulsed heating power supply for outputting a heating voltage.

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