JP2010226148A - Semiconductor manufacturing apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To block spark at connections of a heater power feed line and the terminal of a semiconductor manufacturing apparatus to prevent the heater power feed line from damage. <P>SOLUTION: The apparatus includes a substrate process chamber 12, a heater for heating the substrate 13 stored in the substrate process chamber, a heater power feed line 48 for feeding the heater with power, and a terminal connected to the heater power feed line and a power feed source. The sharp edge is cut off from at least the corner of the terminal touching the heater power feed line. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention generates plasma and decomposes the reactive gas by the plasma to oxidize the surface of the substrate such as a wafer to generate an oxide film, or to perform diffusion treatment such as nitriding, or to etch the substrate surface The present invention relates to a semiconductor manufacturing apparatus that manufactures a semiconductor device by performing various processes such as the above.

  As one of semiconductor manufacturing apparatuses, there is an apparatus (hereinafter referred to as an MMT apparatus) that plasma-treats a substrate such as a wafer using a modified magnetron type plasma source that generates high-density plasma by an electric field and a magnetic field. is there.

  In this MMT apparatus, a substrate to be processed is placed on a substrate holding means (susceptor) provided in an airtight processing chamber, the substrate is heated via the substrate holding means, and a reaction gas is supplied to the processing chamber via a shower plate. The high pressure power is supplied to the discharge electrode to form an electric field and a magnetic field is applied to cause magnetron discharge.

  The electrons emitted from the discharge electrode continue to circulate while continuing the cycloid motion while drifting, so that the lifetime is increased and the ionization rate is increased, so that high-density plasma is generated. In this way, the reaction gas is excited and decomposed, and the substrate surface is subjected to various plasma treatments, such as diffusion treatment such as oxidation or nitridation, or forming a thin film on the substrate surface, or etching the substrate surface.

  A conventional susceptor incorporates a high-frequency electrode according to the necessity of plasma processing together with a metal heater such as tungsten (W), and the heater and the high-frequency electrode are enclosed by aluminum nitride (AlN). It was a structure. The high-frequency electrode is for applying a bias voltage to the substrate to be processed by applying a high-frequency voltage, and the heater is for heating the substrate to be processed through an AlN substrate holder. However, in the conventional susceptor, the substrate to be processed cannot be heated at 550 ° C. or higher because of AlN damage due to thermal stress in a high temperature region. In addition, there is a problem that the substrate to be processed is contaminated by aluminum generated from AlN as an outer skin during plasma processing.

  In order to solve this problem, there is a heater and a quartz-coated susceptor that covers the high-frequency electrode with quartz, and the quartz-coated susceptor uses a ceramic heater such as SiC that facilitates the introduction of a large current and can be used in the atmosphere. The structure is adopted. In the AlN-coated susceptor, the cross-sectional area where the power feed line connected to the metal heating element is sufficiently wide in consideration of the specific resistance of the metal material of the power line. There was almost no. In the case of a ceramic heater, the specific resistance is several hundred times larger than that of metal, so the cross-sectional area where the heating element and the power feed line are connected must be widened, but compatibility with the heater of the AlN-coated susceptor must be maintained. Therefore, since the cross-sectional area where the heating element and the power feed line are connected cannot be widened, heat generation that cannot be ignored even with the power feed line is predicted. Temperature can rise.

  Since the temperature of the terminal portion also increases from about 300 ° C. to about 450 ° C., the surface of the terminal connected to the terminal portion is hardly oxidized to a relatively high temperature, such as Ni, and an insulating film is not easily formed on the contact portion. Material is used.

  A conventional contact portion will be described with reference to FIG.

  In FIG. 5, 1 is a heater power feed line extending from a heating element (for example, made of SiC), 2 is a metal terminal portion (for example, made of Ni) fixed to the heater power feed line 1 by a bolt 3, A power supply cable 4 is fixed to the terminal portion 2 with a bolt 5.

  When the heater power feed line 1 and the terminal portion 2 are connected so as to overlap as shown in FIG. 5, the ceramic heater power feed line 1 and the metal terminal portion 2 are connected as shown in FIG. Due to the difference in specific resistance, a larger amount of current flows on the terminal portion 2 side, and the current is concentrated on the tip portion 6 of the terminal portion 2. For this reason, a spark may occur between the pointed portion 6 and the heater power feed line 1 and the heater power feed line 1 may be damaged.

  In view of such a situation, the present invention suppresses the occurrence of sparks at a connection portion between a heater power feed line and a terminal portion in a semiconductor manufacturing apparatus, and prevents damage to the heater power feed line made of ceramic.

  The present invention relates to a substrate processing chamber, a heater for heating a substrate housed in the substrate processing chamber, a heater power feed line for supplying power to the heater, a power supply source connected to the heater power feed line And a terminal part connected to the semiconductor device, wherein a tip is removed from at least a corner part of the terminal part contacting the heater power feed line.

  According to the present invention, the substrate processing chamber, the heater for heating the substrate accommodated in the substrate processing chamber, the heater power feed line for supplying power to the heater, and the heater power feed line connected to the power A terminal portion connected to a supply source, and the tip portion is removed from at least a corner portion of the terminal portion that contacts the heater power feed line, so that the power flowing through the terminal portion is not concentrated on the tip portion, and the terminal portion It is possible to suppress the occurrence of sparks between the heater power feed line and the heater power feed line contact portion and to prevent damage to the heater power feed line.

It is a general | schematic front sectional view which shows embodiment of this invention. It is sectional drawing of the susceptor in this embodiment. It is a fragmentary figure which shows the connection structure of the terminal in this embodiment. It is a fragmentary figure which shows the connection structure of the other terminal which concerns on this invention. It is explanatory drawing which shows the connection structure of the conventional terminal. It is explanatory drawing which shows the connection structure of the conventional terminal.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  An MMT apparatus which is an example of a semiconductor manufacturing apparatus in which the present invention is implemented will be described with reference to FIGS.

  The MMT apparatus includes a substrate processing furnace 11 that performs plasma processing on a substrate such as a wafer using a modified magnetron type plasma source that can generate high-density plasma by an electric field and a magnetic field.

  In the substrate processing furnace 11, a substrate 13 such as a wafer is installed in a substrate processing chamber 12 that ensures airtightness, and a reaction gas 15 is introduced into the substrate processing chamber 12 through a shower plate 14. Is maintained at a certain pressure, high frequency power is supplied to the discharge electrode to form an electric field, and a magnetic field is applied to cause magnetron discharge. The electrons emitted from the discharge electrode continue to circulate in a cycloidal motion while drifting, and high-density plasma is generated.

  The reaction gas 15 is excited and decomposed, the surface of the substrate 13 is oxidized, nitridation or the like is diffused, a thin film is generated on the surface of the substrate 13, or the surface of the substrate 13 is etched.

  This will be specifically described below.

  The substrate processing chamber 12 is formed from a lower container 16 that is a second container and an upper container 17 that is a first container placed on the lower container 16. The upper container 17 is made of dome-shaped aluminum oxide or quartz, and the lower container 16 is made of aluminum. Further, the susceptor 20 which is a heater-integrated substrate mounting table, which will be described later, is made of ceramics or quartz, thereby reducing metal contamination taken into the film during processing.

  A shower head 19 that forms a buffer chamber 18 that is a gas dispersion space is provided above the upper container 17, and a gas inlet 21 that is an inlet for introducing gas is provided on the upper wall of the shower head 19. The lower wall is composed of the shower plate 14 having gas ejection holes 22 which are ejection holes for ejecting gas. The gas inlet 21 is connected to a reaction gas supply source (not shown) via a gas supply pipe 23 which is a gas supply pipe and a valve 24 which is an on-off valve and a mass flow controller 25 which is a flow rate control means. Has been.

  The reaction gas 15 is supplied from the shower head 19 to the substrate processing chamber 12, and the lower container 16 is arranged so that the gas after substrate processing flows from the periphery of the susceptor 20 toward the bottom of the substrate processing chamber 12. A gas exhaust port 26 for exhausting gas is provided on the side wall. The gas exhaust port 26 is connected to a vacuum pump 31 as an exhaust device through a pressure regulator 28 and an on-off valve 29 by a gas exhaust pipe 27 for exhausting gas.

  The discharge means for exciting the supplied reaction gas 15 has a cylindrical cross section, and a cylindrical electrode 32, which is preferably a cylindrical first electrode, is provided on the outer periphery of the upper vessel 17. The cylindrical electrode 32 surrounds the plasma generation region 33 in the substrate processing chamber 12. The cylindrical electrode 32 is connected to a high frequency power source 35 that applies high frequency power via a matching unit 34 that performs impedance matching.

  The cross section is cylindrical, and preferably a cylindrical magnetic field forming means (permanent magnet) 36 can be used. The magnetic field forming means 36 is configured to form magnetic lines of force in the cylindrical axis direction along the inner peripheral surface of the cylindrical electrode 32.

  In the center of the bottom side of the substrate processing chamber 12, the susceptor 20 is arranged as a substrate holding means for holding the substrate 13, and the susceptor 20 can heat the substrate 13.

  As shown in FIG. 2, the susceptor 20 is composed of, for example, a quartz container 37, and a heater 38 as a heating means and a high-frequency electrode 39 as a bias voltage applying means are integrally embedded therein. Therefore, the surfaces of the heater 38 and the high-frequency electrode 39 are covered with quartz and are not exposed to the substrate processing chamber 12. The substrate 38 can be heated to about 800 ° C. by supplying heater power to the heater 38 via a heater power feed line 48. As the material of the heater 38, for example, SiC or MoSi2 is used.

  The high-frequency electrode 39 is connected to an impedance variable mechanism 41 via a high-frequency feed line 49 and is grounded via the impedance variable mechanism 41. The variable impedance mechanism 41 includes a coil and a variable capacitor. The bias potential of the substrate 13 can be controlled via the electrode and the susceptor 20 by controlling the number of coil patterns and the capacitance value of the variable capacitor. It has become.

  Around the cylindrical electrode 32 and the magnetic field forming unit 36, the electric field and magnetic field formed by the cylindrical electrode 32 and the magnetic field forming unit 36 do not adversely affect the external environment and other processing furnaces. Further, a shielding plate 42 that effectively shields an electric field and a magnetic field is provided.

  The susceptor 20 is insulated from the lower container 16, and the lower container 16 is provided with a susceptor elevating mechanism 43 as elevating means for elevating and lowering the susceptor 20. The susceptor 20 has through-holes 44, and substrate support pins 45, which are substrate protrusion means for protruding the substrate 13, are provided on at least three positions on the bottom surface of the lower container 16. When the susceptor 20 is lowered by the susceptor elevating mechanism 43, the substrate support pin 45 can be inserted through the through hole 44 in a non-contact state with the susceptor 20.

  A gate valve 46 serving as a gate valve is provided on the side wall of the lower container 16, and a transfer chamber (not shown) is connected through the gate valve 46, and when the gate valve 46 is open, The substrate processing chamber 12 can be hermetically closed when the substrate 13 is loaded into or unloaded from the substrate processing chamber 12 by a transfer means omitted in the middle and closed.

  The controller 47 as a control means includes the high-frequency power source 35, the matching unit 34, the valve 24, the mass flow controller 25, the pressure regulator 28, the on-off valve 29, the vacuum pump 31, the susceptor lifting mechanism 43, The gate valve 46 and the heater 38 embedded in the susceptor 20 are connected to a high-frequency power source for applying high-frequency power to control each of them.

  A terminal portion 51 is fixed to the heater power feed line 48 by fixing means such as a bolt, and the terminal portion 51 is fixed to a tip of a power supply cable (see FIG. 5), and a power supply source is connected via the power supply cable. (Not shown). A connection structure between the heater power feed line 48 and the terminal portion 51 will be described in detail with reference to FIG.

  The feed line tip 48a of the heater power feed line 48 has a thin plate shape, and the feed line is changed in thickness at the boundary between the heater power feed line 48 and the feed line tip 48a. The base of the tip 48a has an R shape so that stress concentration does not occur.

  The terminal portion 51 is made of metal, for example, a metal material that does not oxidize to a high temperature and is difficult to form an oxide film on the surface, such as a Ni material. The terminal tip portion 51a of the terminal portion 51 has a stepped shape with the side that contacts the feed wire tip portion 48a cut off, and is in contact with the tip corner portion of the terminal tip portion 51a, particularly the feed wire tip portion 48a. The tip corner portion 51b on the side to be bent has an R shape.

  The connection between the feed wire tip 48a and the terminal tip 51a is fixed with a bolt (not shown) so that a part thereof overlaps, and the tip of the terminal tip 51a and the heater power feed line 48 are connected. A gap is formed between the tip of the feed wire tip 48a and the terminal 51. The tip of the feed wire tip 48 is in contact with the tip of the terminal tip 51a and the heater power feed line 48, and the tip of the feed wire tip 48a and the terminal 51 are contacted with no gap. When 48a and the terminal tip 51a are fixed, the other corners 51c and 51d are also formed in an R shape. A chamfered shape may be used instead of the R shape. In short, it is sufficient that the terminal tip 51a has such a shape that no tip is formed at the tip corner.

  Hereinafter, a method of performing a predetermined plasma treatment on the surface of the substrate 13 or the surface of the base film formed on the substrate 13 will be described.

  The substrate 13 is carried into the substrate processing chamber 12 from the outside of the substrate processing chamber 12 by a transfer means (not shown) and transferred onto the susceptor 20. The details of the transfer operation are as follows. First, the susceptor 20 is lowered, and the tip of the substrate support pin 45 passes through the through hole 44 of the susceptor 20 and has a predetermined height from the surface of the susceptor 20. The gate valve 46 provided in the lower container 16 is opened in a state where the substrate 13 is protruded, and the substrate 13 is placed on the front end of the substrate support pin 45 by a conveying means not shown in the figure. When retreating out of the substrate processing chamber 12, the gate valve 46 is closed, and when the susceptor 20 is raised by the susceptor elevating mechanism 43, the substrate 13 can be placed on the upper surface of the susceptor 20. Ascend to the processing position.

  Electric power is supplied to the heater 38 embedded in the susceptor 20 through the terminal portion 51 and the heater power feed line 48 and heated in advance. Heat to substrate processing temperature within range. Using the vacuum pump 31 and the pressure regulator 28, the pressure in the substrate processing chamber 12 is maintained within a range of 0.1 to 100 Pa.

  In the process of supplying electric power through the terminal part 51 and the heater power feed line 48, since the specific resistance of the heater power feed line 48 is large with respect to the terminal part 51, current is supplied to the terminal tip part 51a. However, since the tip corner portion 51b has an R shape, current concentration on the tip corner portion 51b is avoided, and a spark is generated between the tip corner portion 51b and the feed wire tip portion 48a. Is prevented, and damage to the feed wire tip 48a is prevented.

  The substrate 13 is heated to a processing temperature, and reaction gas (for example, N 2, O 2, NH 3, NF 3, PH 3) is supplied from the gas inlet 21 through the gas ejection holes 22 of the shower plate 14 to the upper surface of the substrate 13. Introduced in a distributed manner (processing surface). The gas flow rate at this time is in the range of 100 to 1000 sccm. At the same time, high frequency power is applied to the cylindrical electrode 32 from the high frequency power source 35 via the matching unit 34. As the power to be applied, an output value in the range of 100 to 500 W is input. The impedance variable mechanism 41 is controlled in advance to a desired impedance value.

  A magnetron discharge is generated under the influence of the magnetic field of the magnetic field forming means 36, and charges are trapped in the space above the substrate 13 to generate high-density plasma in the plasma generation region 33. Plasma processing is performed on the surface of the substrate 13 on the susceptor 20 by the generated high-density plasma. The substrate 13 that has been subjected to the surface treatment is transported out of the substrate processing chamber 12 using a transport means (not shown) in the reverse order of the substrate loading.

  The controller 47 controls the supply of current to the heater 38, turns on / off the high-frequency power source 35, adjusts the matching unit 34, opens / closes the valve 24, the flow rate of the mass flow controller 25, and the pressure regulator. 28, opening / closing of the opening / closing valve 29, starting / stopping of the vacuum pump 31, raising / lowering operation of the susceptor raising / lowering mechanism 43, opening / closing of the gate valve 46, application of high frequency power to the high frequency electrode 39 of the susceptor 20 The power ON / OFF to the high frequency power supply (not shown) is controlled.

  Next, since the contact area between the heating element and the power feed line cannot be increased as described above in the connection between the feed wire tip 48a and the terminal tip 51a, heat generation at the contact portion is increased. The temperature becomes 300 ° C to 450 ° C. Also, the feed wire tip 48a and the terminal tip 51a have different coefficients of thermal expansion, causing a difference in thermal expansion. If the feed wire tip portion 48a and the terminal tip portion 51a are firmly fixed, there is a risk that stress due to a difference in thermal expansion is generated and the feed wire tip portion 48a is damaged due to the generated stress.

  Therefore, as a means for suppressing the occurrence of stress due to a difference in thermal expansion, a conductive sliding member, such as a carbon plate, is sandwiched on the contact surface between the feed wire tip portion 48a and the terminal tip portion 51a. Slip occurs between the wire tip 48a and the terminal tip 51a, thereby reducing the generation of stress. In addition, when carbon is used as the sliding member, the carbon is soft and conforms to the surface, so that the unevenness of the contact surface is filled to reduce the contact resistance between the feed wire tip portion 48a and the terminal tip portion 51a. Reduces heat generation.

  FIG. 4 shows a connection structure between another heater power feed line 48 and the terminal portion 51.

  The terminal portion 51 shown in FIG. 4 has a bifurcated fork shape having two terminal tip portions 51a and 51a at the tip, and the bolt 3 is used so that the feed wire tip portion 48a is sandwiched between the terminal tip portions 51a and 51a. It is fixed.

  By sandwiching between the terminal tip portions 51a and 51a, the contact area between the feed wire tip portion 48a and the terminal tip portion 51a is increased, the contact resistance is reduced, and the heat generation amount is reduced. Furthermore, since the current flows evenly on both sides of the feed wire tip 48a as shown by the arrows in the figure, the amount of heat generated on both sides is equalized, the thermal expansion difference becomes uniform, and both sides are affected by thermal stress. Bending deformation is offset. Therefore, there is no possibility that the feed wire tip 48a is broken or damaged due to the difference in thermal expansion.

  In addition, although the said embodiment showed the case where this invention was implemented in the MMT apparatus, it cannot be overemphasized that it can implement in other semiconductor manufacturing apparatuses provided with the heater which heats a board | substrate, for example, it is a heat | fever. There is a single wafer type semiconductor manufacturing apparatus that performs CVD or the like.

DESCRIPTION OF SYMBOLS 11 Substrate processing furnace 12 Substrate processing chamber 13 Substrate 20 Susceptor 32 Cylindrical electrode 36 Magnetic field formation means 34 Matching device 35 High frequency power supply 38 Heater 39 High frequency electrode 41 Impedance variable mechanism 47 Controller 48 Heater power feed line 48a Feed line tip 49 High frequency feed Wire 51 Terminal 51a Terminal tip

Claims (3)

A substrate processing chamber;
A heater housed in the substrate processing chamber for heating the substrate;
A ceramic heater power feed line for supplying power to the heater;
A metal terminal connected to the heater power feed line and connected to a power supply source;
A flat feed line tip is formed at the tip of the heater power feed line,
The semiconductor manufacturing apparatus according to claim 1, wherein the terminal portion is fixed to the tip end portion of the feed line so as to be superposed via a conductive sliding member.   The substrate processing apparatus according to claim 1, wherein the conductive sliding member contains carbon. A substrate processing chamber;
A substrate mounting table provided in the substrate processing chamber on which the substrate is mounted;
A heater provided in the substrate mounting table for heating the substrate;
A ceramic heater power feed line for supplying power to the heater;
A metal terminal connected to the heater power feed line and connected to a power supply;
A flat feed line tip is formed at the tip of the heater power feed line,
In the semiconductor manufacturing apparatus configured such that the terminal portion is fixed to the tip of the feed line so as to be polymerized through a conductive sliding member,
Placing the substrate on the substrate placing table;
A method of manufacturing a semiconductor, comprising: supplying power to the heater through the terminal portion, the conductive sliding member, and the heater power feed line, heating the heater, and processing the substrate.