JP2019099837A - Sputtering apparatus, and sputtering method - Google Patents

Abstract

To provide a sputtering apparatus and a sputtering method having good film coatability and its uniform distribution over a substrate surface.SOLUTION: A sputtering apparatus includes a vacuum chamber 1, a sputter pulse power source 30 connected to a target material 7, a deflection coil 21 arranged in a space between the target material 7 and a substrate 6, a deflection coil pulse power source 31 connected to the deflection coil 21, and a pulse timing controller 40 that is connected to the sputter pulse power source 30 and the deflection coil pulse power source 31 and controls pulse timing by synchronizing or shifting the timing of each pulse from the sputter pulse power source 30 and the deflection coil pulse power source 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sputtering apparatus and a sputtering method for forming a film on a substrate such as a semiconductor wafer.

  In the manufacture of semiconductor devices and electronic devices, thin films of metals, oxides, etc. are formed on a substrate, and the thin films are formed into a desired pattern, and resistors, capacitors, etc. are formed in addition to electrodes and wirings. . In recent years, miniaturization of semiconductor devices has progressed, and the aspect ratio (depth / trench width or hole diameter) of trenches and holes formed on a substrate tends to be large. Further, in the case of an electronic device which is required to have heat resistance, it may be manufactured using a ceramic sintered substrate having high thermal conductivity but having submicron irregularities on the surface. As described above, in a substrate having irregularities of trenches or holes on the surface, or a substrate having irregularities of submicron, plating seed films of wiring materials, resistance films of resistance devices, etc. on side wall portions or bottom portions of these irregularities. There is an increasing demand for uniformly forming moisture-proof protective films of various devices.

  Conventionally, there is a pulse sputtering method as one of the film forming means for improving the coverage of a thin film formed on such a concavo-convex portion (see, for example, Patent Document 1).

  Hereinafter, the conventional pulse sputtering method will be described with reference to FIG. FIG. 8 is a cross-sectional view showing a schematic configuration of a pulse sputtering apparatus for performing the conventional pulse sputtering method.

  In the conventional pulse sputtering apparatus shown in FIG. 8, the inside of the vacuum chamber 101 is depressurized to a vacuum state by evacuating it with a vacuum pump 102 connected via a valve 103. The gas supply source 104 can supply the gas necessary for sputtering into the vacuum chamber 101 at a constant rate. The degree of vacuum in the vacuum chamber 101 can be controlled to a desired gas pressure by changing the open / close rate of the valve 103. In the vacuum chamber 101, a target material 107 is disposed. The backing plate 108 supports the target material 107. The sputter pulse power supply 130 is electrically connected to the backing plate 108. By applying a voltage to the target material 107 through the backing plate 108, the sputtering pulse power source 130 can dissociate a part of the gas in the vacuum chamber 101 and generate plasma. In addition, the sputtering pulse power supply 130 can apply a pulse that repeats the on / off of the output at a constant timing. A substrate 106 is disposed inside the vacuum chamber 101 so as to face the target material 107. The substrate holder 105 is disposed below the substrate 106 and supports the substrate 106. The substrate bias DC power supply 133 is electrically connected to the substrate holder 105, and can set the substrate potential by applying a voltage. The sputtering condition setting unit 141 is connected to the sputtering pulse power supply 130 and the bias DC power supply 133, and sets the on / off ratio of pulse voltage application of the sputtering pulse power supply 130 and the bias voltage setting of the bias DC power supply 133. You can indicate and control the value.

  During the on period of the pulse voltage application, the target material 107 is sputtered out by the pulsed plasma generated in the vacuum chamber 101. At that time, some of the material particles that have jumped out are ionized and become positively charged charged particles, and the remaining material particles are neutral particles. The ejected neutral particles reach the substrate 106 and a thin film of the target material 107 is deposited. The charged particles are attracted and accelerated by the potential applied to the substrate 106, and are incident on the substrate 106 at an angle closer to perpendicular to the substrate 106 than the neutral particles, so the bottom of the recess of the substrate 106 It is easy to reach. The gas and plasma in the vacuum chamber 101 react with material particles being deposited on the substrate 106 to form a target compound. Further, even during the off period of the pulse voltage application, the gas and plasma in the vacuum chamber 101 react with the target material 107 deposited on the substrate 106 to form a dense compound in which the target material 107 and the gas react. Be done. A compound thin film is formed on the substrate 106 by repeating this series of pulse film formation a predetermined number of times.

  In general, the magnet 109 and the yoke 110 are disposed on the back surface of the target material 107, and the plasma is concentrated on the surface of the target material 107 at a position where the parallel magnetic field with respect to the plane of the target material 107 is maximum. The deposition rate is improved. The position where this plasma is concentrated is called erosion. In addition, when erosion concentrates on a specific position, only a part of the target material 107 is consumed, and the material can not be used efficiently, so the magnet 109 and the yoke 110 are not shown in FIG. It may move parallel to move the erosion position.

Unexamined-Japanese-Patent No. 2004-266112

  However, in the above-described conventional pulse sputtering apparatus (see FIG. 8), since the incident angle of ionized particles can not be controlled, sufficient coverage can be obtained in a substrate having a larger aspect ratio asperity. In particular, the coverage of the bottom of the recess and the side wall near the bottom may not be sufficient. In addition, since the erosion of the surface of the target material 107 has a ring shape and the particles do not fly out in an isotropic direction, the incident angle of the particles to the substrate 106 is different at the position of the substrate 106 surface. . As a result, there is a problem that the in-plane distribution of the substrate is largely different and not uniform with respect to the covering property, and there is a problem that the quality and the yield of the device are deteriorated.

  SUMMARY OF THE INVENTION The present invention provides a sputtering apparatus and a sputtering method capable of forming a film having good thin film coverage and uniformity of in-plane distribution of the substrate, taking into consideration the problems in the above-described conventional pulse sputtering apparatus. The purpose is

The sputtering apparatus of the present invention comprises a vacuum chamber in which a target material and a substrate are disposed, and a sputter pulse power source connected to the target material, generating plasma in the vacuum chamber to form a thin film on the substrate A sputtering apparatus for forming
The sputtering apparatus includes a deflection coil disposed in a space between the target material and the substrate, a deflection coil pulse power supply connected to the deflection coil, the sputtering pulse power supply, and the deflection coil pulse power supply. And a pulse timing controller connected to perform control to synchronize or shift the timing of each pulse from the sputtering pulse power supply and the deflection coil pulse power supply.

  According to the present invention, the flying direction of the ionized particles can be controlled to be deflected to an angle suitable for the asperity shape of the substrate, so that a sputtering apparatus and a sputtering method can be provided in which the coverage of the thin film is improved. That is, in the sputtering apparatus and the sputtering method according to the present invention, coating of the bottom by an angle close to the vertical, coating to the side wall by control to a shallow incident angle, and control by reversing the incident angle Coating on the opposite side can effectively enhance the coverage. In addition, since the sputtering apparatus and the sputtering method of the present invention can apply the substrate bias without adversely affecting the deflection, for example, the overhang generated in the uneven portion such as the trench or the hole of the substrate is reduced, and the substrate concave portion It has the effect of further improving the coverage of the side wall and bottom of the

Sectional drawing which shows schematic structure of the sputter apparatus of Embodiment 1 which concerns on this invention. The figure which shows typically the deflection | deviation by the magnetic field of ionized particle | grains in the sputter apparatus of Embodiment 1 which concerns on this invention. In the sputtering apparatus of Embodiment 1 which concerns on this invention, the schematic diagram of the deflection | deviation coil seen from the direction of arrow A in FIG. The figure which shows typically the incident angle to the board | substrate of the particle | grains etc. which were deflected in the sputter apparatus of Embodiment 1 which concerns on this invention. In the sputtering apparatus according to the first embodiment of the present invention, a waveform chart showing application timings of a sputtering pulse signal and a magnetic field deflection pulse signal Sectional drawing which shows schematic structure of the sputter apparatus of Embodiment 2 which concerns on this invention. In the sputtering apparatus of Embodiment 2 according to the present invention, a waveform chart showing application timings of a sputtering pulse signal, a magnetic field deflection pulse signal and a substrate bias pulse signal Sectional view showing a schematic configuration of a conventional pulse sputtering apparatus

First, the configurations of various aspects in the sputtering apparatus and the sputtering method according to the present invention will be described.
The sputtering apparatus according to the first aspect of the present invention is
A sputtering apparatus comprising: a vacuum chamber in which a target material and a substrate are disposed; and a sputtering pulse power source connected to the target material, wherein plasma is generated in the vacuum chamber to form a thin film on the substrate. ,
The sputtering apparatus includes a deflection coil disposed in a space between the target material and the substrate, a deflection coil pulse power supply connected to the deflection coil, the sputtering pulse power supply, and the deflection coil pulse power supply. And a pulse timing controller connected to perform control to synchronize or shift the timing of each pulse from the sputtering pulse power supply and the deflection coil pulse power supply.

  The sputtering apparatus of the first aspect configured as described above can control the flying direction of the ionized particles to an angle suitable for the concavo-convex shape of the substrate, and thus improve the coverage of the thin film. It can.

The sputtering apparatus according to the second aspect of the present invention is the sputtering apparatus according to the first aspect described above,
A bias pulse power supply connected to the substrate, the sputtering pulse power supply, the deflection coil pulse power supply, and the bias pulse power supply are connected to each other from the sputter pulse power supply, the deflection coil pulse power supply, and the bias pulse power supply. And a pulse timing controller that performs control to synchronize or shift the timing of the pulses.

  The sputtering apparatus according to the second aspect configured as described above can apply the substrate bias without adversely affecting the deflection, so that, for example, the overhang generated in the uneven portion such as the trench or the hole of the substrate is reduced. It is possible to further improve the coverage of the side wall and the bottom of the substrate recess.

A sputtering method according to a third aspect of the present invention is a sputtering method utilizing the sputtering apparatus according to the first or second aspect, wherein
The pulse timing controller performs control such that the on timing of the pulse of the deflection coil pulse power supply is turned on after the lapse of a period of 0 μsec or more and 100 μsec or less from the off time of the pulse of the sputter pulse power supply.

  In the sputtering method of the third aspect configured as described above, the flying direction of the ionized particles can be controlled to be deflected to an angle suitable for the concavo-convex shape of the substrate, so that the coverage of the thin film can be improved. It can.

A sputtering method according to a fourth aspect of the present invention is a sputtering method utilizing the sputtering apparatus according to the second aspect, wherein
The pulse timing controller applies the on timing of the pulse of the bias pulse power in synchronization with the on of the pulse of the sputtering pulse power, and the off timing of the pulse of the bias pulse power corresponds to the sputtering pulse power. Control is performed to turn off after a period of 0 μsec or more and 30 μsec or less elapses from the point of time when the pulse is off.

  The sputtering method according to the fourth aspect configured as described above can apply a substrate bias without adversely affecting deflection, so that, for example, an overhang that occurs in an uneven portion such as a trench or a hole of the substrate is reduced. It is possible to further improve the coverage of the side wall and the bottom of the substrate recess.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the description of the embodiments, the same elements are denoted by the same reference signs, and redundant description of the same signs may be omitted. Also, the drawings schematically show the respective components mainly for the purpose of easy understanding.

  Each embodiment described below shows one specific example of the present invention. Numerical values, shapes, configurations, steps, order of steps, and the like shown in the following embodiments are merely examples and do not limit the present invention. Among the components in the following embodiments, components that are not described in the independent claim indicating the highest concept are described as optional components.

Embodiment 1
Hereinafter, the sputtering apparatus of Embodiment 1 which concerns on this invention is demonstrated using FIGS. 1-4. FIG. 1 is a cross-sectional view showing a schematic configuration of a sputtering apparatus according to a first embodiment of the present invention. 2 to 4 are diagrams for explaining the sputtering operation and the sputtering method in the sputtering apparatus of the embodiment 1, and the details will be described later.

  In the sputtering apparatus according to the first embodiment shown in FIG. 1, the vacuum chamber 1 shown in cross section is configured to evacuate the inside of the vacuum chamber 1 to a vacuum state by evacuating with the vacuum pump 2 connected via the valve 3 It is.

  The gas supply source 4 can supply the gas necessary for sputtering to the vacuum chamber 1 at a constant rate. As the gas supplied from the gas supply source 4, for example, a gas having reactivity with a target material such as nitrogen or oxygen, or a mixed gas of a reactive gas and a rare gas such as argon is selected. it can.

  The valve 3 provided in the vacuum chamber 1 can control the degree of vacuum in the vacuum chamber 1 to a desired gas pressure by changing the open / close rate.

  As shown in FIG. 1, a target material 7 which is a target material for sputtering is disposed in the upper part in the vacuum chamber 1. The target material 7 is any sputtering material, and is, for example, an inorganic material such as a metal material or a semiconductor material.

  A backing plate 8 provided in the vacuum chamber 1 supports the target material 7. The sputtering pulse power supply 30 provided outside the vacuum chamber 1 is electrically connected to the target material 7 via the backing plate 8, and a voltage can be applied to the target material 7. Further, the sputtering pulse power supply 30 can store direct current generated by the internal high voltage power supply in a capacitor or the like, turn it on and off with a semiconductor switching element or the like, and pulse the voltage application.

  The magnet 9 and the yoke 10 provided in the vacuum chamber 1 are disposed on the back surface of the backing plate 8 and can generate a magnetic field on the surface of the target material 7.

  In FIG. 1, a substrate 6 is disposed in the lower part of the vacuum chamber 1. The substrate holder 5 is disposed below the substrate 6 and supports the substrate 6. The substrate rotation mechanism 20 is connected to the substrate holder 5 and can rotate the substrate 6 about its rotation axis.

  In FIG. 1, a pair of deflection coils 21 is disposed opposite to each other in a space between the target material 7 and the substrate 6 disposed opposite to each other. The deflection coil pulse power supply 31 is electrically connected to the opposing deflection coil 21, and can generate a magnetic field in the space between the target material 7 and the substrate 6 by supplying a current to the deflection coil 21. Further, the deflection coil pulse power supply 31 can output a pulse current to the deflection coil 21 by pulsing the voltage application in the same manner as the sputtering pulse power supply 30.

  In FIG. 1, a pulse timing controller 40 connected to a sputtering pulse power supply 30 and a deflection coil pulse power supply 31 is disposed outside the vacuum chamber 1. The pulse timing controller 40 can perform control to synchronize or shift the timing between the sputtering by the sputtering pulse power supply 30 and the magnetic field generation by the deflection coil 21.

[Sputtering Operation and Sputtering Method of Sputtering Apparatus]
Next, the sputtering operation of the sputtering apparatus of Embodiment 1 will be described, and the sputtering method of the present invention will also be described. The sputtering operation and the sputtering method described below are substantially the same as in Embodiment 2 described later.

  First, the target material 7 is set in the vacuum chamber 1, and the substrate 6 is set below the target material 7 so that the main surface of the substrate 6 is horizontal.

  Subsequently, the vacuum pump 2 is operated to reduce the pressure so that the inside of the vacuum chamber 1 is in a vacuum state. After the inside of the vacuum chamber 1 reaches a predetermined degree of vacuum, a gas is introduced from the gas supply source 4 into the vacuum chamber 1, and the opening degree of the gate valve 3 is adjusted so that the inside of the vacuum chamber 1 has a predetermined gas pressure. adjust.

  Subsequently, a pulse voltage is generated by the sputtering pulse power source 30 and applied to the target material 7 to generate plasma in the vacuum chamber 1. During the on period of the pulse voltage application, the target material 7 is sputtered out by the pulsed plasma generated in the vacuum chamber 1. At that time, some of the material particles that have jumped out are ionized and become positively charged charged particles, and the remaining material particles are neutral particles.

  Next, a trajectory until ionized particles reach the substrate 6 will be described with reference to FIG. FIG. 2 is a view schematically showing the direction of deflection of the ionized particles by the magnetic field and the direction of incidence on the substrate in the sputtering apparatus of Embodiment 1 according to the present invention.

  In FIG. 2, the flow of ionized particles ejected from the target material 7 is represented as current I. The deflection coil 21 disposed opposite to the space between the target material 7 and the substrate 6 generates a magnetic field B in the direction component perpendicular to the current I. The ionized particles receive Lorentz force F in the direction perpendicular to the current I and the magnetic field B, and thus enter the substrate 6 at an angle with respect to the trajectory of neutral particles not subjected to the Lorentz force F.

  Next, the incident direction of the ionized particles (ion particles) on the substrate 6 will be described with reference to FIG. FIG. 3 is a schematic view of the deflection coil 21 as viewed in the direction of arrow A in FIG. When a magnetic field B in the forward direction of the sheet of FIG. 3 is generated by supplying a current to the deflection coil 21 in the direction of arrow B, the ionized particles traveling downward, ie, the current I receive the Lorentz force F in the right direction. , Is deflected to the right.

  FIG. 4 is a cross-sectional view schematically showing incident directions of neutral particles and ionized particles to the substrate 6. In FIG. 4, (a) and (c) are diagrams showing incident directions of deflected ionized particles, and each schematically shows a state of being deflected in the opposite direction. FIG. 4b shows the incident direction of the non-deflected ionized particles. In FIG. 4, the incident direction of neutral particles is indicated by a solid arrow, and the incident direction of ionized particles is indicated by a dashed arrow.

  As shown in FIG. 4A, the ionized particles having reached the vicinity of the substrate 6 enter the substrate 6 at an angle with respect to the trajectory of the neutral particles not subjected to the Lorentz force F. The inclination of this angle can be controlled by the current supplied to the deflection coil 21. That is, when no current flows through the deflection coil 21, as shown in FIG. 4B, since the ionized particles are not deflected, the incident angles of the neutral particles and the ionized particles coincide with each other. Further, by inverting the current supplied to the deflection coil 21, as shown in FIG. 4C, the incident angle of the ionized particles to the substrate 6 becomes an incident angle from the opposite side, and the incident angle is reversed. Can do. As described above, neutral particles and ionized particles are incident on the substrate 6 to form a thin film 7 a on the surface of the substrate 6.

  Next, timing control by the pulse timing controller 40 will be described with reference to FIG. FIG. 5 shows application of a sputtering pulse signal (sputtering voltage V, sputtering current I) from the sputtering pulse power supply 30 and application of a magnetic field deflection pulse signal from the deflection coil pulse power supply 31 in the sputtering apparatus of Embodiment 1 according to the present invention. It is a wave form diagram showing timing. In FIG. 5, (a) shows an example of the pulse waveform of the sputtering voltage V by the sputtering pulse signal, and (b) shows an example of the waveform of the sputtering current I by the sputtering pulse signal. FIG. 5C is a waveform diagram of the magnetic field deflection pulse signal input to the deflection coil 21. As shown in FIG.

  The sputtering voltage V applied to the backing plate 8 by the sputtering pulse signal is a rectangular wave (pulse) repeating an on period (on) and an off period (off) at a constant pulse period T (frequency f = 1 / T). (See (a) of FIG. 5). Further, the duty ratio of the pulse is represented by on period / pulse period T. The sputtering current I tends to gradually increase in the on period of the sputtering voltage V. In addition, the sputtering current I generated by the sputtering pulse signal starts to decrease after entering the off period of the sputtering voltage V, and the sputtering current I continues to flow until about 30 μsec depending on the sputtering conditions. The sputtering current I is approximately in proportion to the number of particles sputtered and the target material 7 pops out. That is, it can be said that sputtered particles sputtered by the generated plasma fly out from the target material 7 toward the substrate 6 in a period of about +30 μsec of the on period of the sputtering voltage V.

  The deflection coil 21 starts the on period of the magnetic field deflection pulse signal after a constant first period = T1 has elapsed from the timing when the sputtering voltage V is off. The constant first period T1 from the off point of the sputtering voltage V is desirably in the range of 0 μsec to 100 μsec. When the first period T1 is a negative period, that is, the on period of the deflection coil 21 is started in the on period of the sputtering voltage V and the magnetic field is generated, the magnetic field generated by the magnet 9 near the target material 7 is disturbed. As a result, plasma discharge on the surface of the target material 7 becomes unstable. Also, as an example under general sputtering conditions, assuming that the velocity of sputtered particles is 1000 m / sec and the distance between the target material 7 and the substrate 6 is 100 mm, the time for the sputtered particles to reach the substrate 6 is calculated to be 100 μsec. Ru. If the first period T1 from the off time of the sputtering voltage V is greater than 100 μsec, the ionized particles will generate a magnetic field after passing through the deflection coil 21, and the ionized particles will be sufficiently deflected by the magnetic field I can not The first period T1 is more preferably 30 μsec or more. By setting the first period T1 to 30 μsec or more, the plasma coil is not generated by the deflection coil 21 in the plasma attenuation process of about 30 μsec from the off point of the sputtering voltage V, thereby affecting the plasma discharge on the surface of the target material 7 Can be eliminated, and a more stable discharge state can be obtained. For the same reason, the off time of the pulse voltage of the deflection coil 21 may be up to the timing when the next sputtering voltage V is on (see the second period T2 in (c) of FIG. 5).

  Although the pulse period T in the sputtering apparatus of Embodiment 1 does not directly affect the deflection by the magnetic field, it is preferable to set it to 30 μsec or more (the frequency is less than 33 kHz). This is because if the pulse cycle T is less than 30 μsec, the constant first period T1 from the off time of the sputtering voltage V can not be made more than 30 μsec, which is a more desirable condition. Further, as the pulse duty ratio is smaller, the sputtering power is concentrated in the on period, and the power density is increased, whereby the ionization rate of sputtered particles is increased. The range of the duty ratio that can be set is regulated by the capability of the sputter pulse power supply 30, but if it is desired to further increase the effect of magnetic field deflection, the duty ratio may be set small within the capability range of the sputter pulse power supply 30.

  Further, in the sputtering apparatus according to the first embodiment, the substrate rotation mechanism 20 rotates the substrate 6 to change the incident angle of sputtered particles to the substrate 6, thereby averaging the distribution of the thin film 7a on the surface of the substrate 6. The coverage of the thin film on the uneven portion of the surface of the substrate 6 can be further improved.

  As described above, in the sputtering apparatus of Embodiment 1, the sputtered particles having reached the substrate 6 by performing the sputtering operation by the sputtering method are deposited on the substrate 6 and at the same time with the gas and plasma in the vacuum chamber 1. react. In addition, of the pulse periods T in which sputtered particles are intermittently supplied in the sputtering operation, a period during which material particles are not supplied to the substrate 6 [(pulse period T)-(on period)-(from an off time of sputtering voltage V During a certain first period T1), the gas and plasma in the vacuum chamber 1 react with the unreacted target material 7 deposited on the substrate 6 to react without loss of gas between the target material 7 and the gas. The dense compound is formed on the substrate 6 and formed into a film. A desired compound thin film can be obtained on the substrate surface by repeating this series of pulse film formation a predetermined number of times.

  In the sputtering apparatus of Embodiment 1, the magnet 9 and the yoke 10 are disposed on the back surface of the target material 7, and the surface parallel to the plane of the target material 7 is at the maximum position on the surface of the target material 7. The deposition rate may be improved by concentrating the plasma. When erosion where concentration of plasma concentrates at a specific position, only a part of the target material 7 is consumed and the material can not be used efficiently. Therefore, the magnet 9 and the yoke 10 are parallel to the target material 7 by a drive device. To move the erosion position.

  In the sputtering apparatus of Embodiment 1, the incident angle of the ionized particles to the substrate 6 can be controlled by the magnetic field of the deflection coil 21 without impairing the stability of the plasma discharge in sputtering, so the aspect ratio is large. Even for a substrate having an uneven portion, the coating can be effectively performed by covering the bottom with an angle close to the vertical, covering to the side wall by controlling to the shallow incident angle, and covering to the opposite side by controlling the incident angle. It is possible to perform film formation with improved properties.

Second Embodiment
Next, the sputtering apparatus of Embodiment 2 which concerns on this invention is demonstrated using FIG. 6 and FIG. FIG. 6 is a cross-sectional view showing a schematic configuration of a sputtering apparatus of Embodiment 2 according to the present invention. FIG. 7 is a waveform chart showing a sputtering operation and a sputtering method in the sputtering apparatus of Embodiment 2. 6 and 7, elements having substantially the same functions and configurations as those of the first embodiment described above are given the same reference numerals. Further, since the basic operation in the second embodiment is the same as the basic operation in the first embodiment, the difference between the second embodiment and the first embodiment will be mainly described.

  In the sputtering apparatus of Embodiment 2 shown in FIG. 6, a substrate 6 is provided at the lower part in the vacuum chamber 1. The substrate holder 5 is disposed below the substrate 6 and supports the substrate 6. The substrate rotation mechanism 20 is mechanically connected to the substrate holder 5 and can rotate the substrate 6 about its rotation axis. In the sputtering apparatus of the second embodiment, a bias pulse power supply 32 electrically connected to the substrate 6 through the substrate holder 5 is provided. The bias pulse power supply 32 can set the substrate potential by applying a voltage to the substrate holder 5. In addition, the bias pulse power supply 32 can pulse voltage application (application of bias voltage) as the sputter pulse power supply 30 does.

  As shown in FIG. 5, the pulse timing controller 40 connected to the sputtering pulse power supply 30, the deflection coil pulse power supply 31 and the bias pulse power supply 32 is disposed outside the vacuum chamber 1. The pulse timing controller 40 can control to synchronize or shift the timing of the sputtering by the sputtering pulse power supply 30, the generation of the magnetic field by the deflection coil 21 and the voltage application of the substrate bias by the bias pulse power supply 32.

  By setting the substrate potential by applying the voltage of the bias pulse power supply 32, ionized particles are attracted to the substrate 6 by the electric field in a period in which plasma is generated in the vacuum chamber 1, and film formation is performed by the ion bombardment. It can be expected that the thin film becomes more precise.

  Generally, in the film formation on the concave portion of the substrate 6, a thin film deposition on the upper side wall of the concave portion sometimes causes a situation called an overhang which blocks the opening of the concave portion. In the above, the etching action by ion bombardment can be expected to have the effect of reducing the overhang and promoting the deposition on the sidewall bottom. However, since the application of the bias voltage to the substrate 6 also affects the trajectories of the material particles of the ionized target material 7, the timing of the application of the bias voltage is important.

  The timing control by the pulse timing controller 40 according to the second embodiment will be described with reference to FIG. FIG. 7 shows a sputtering apparatus according to a second embodiment of the present invention, wherein a sputtering pulse signal (sputtering voltage V, sputtering current I) from sputtering pulse power supply 30, a magnetic field deflection pulse signal from deflection coil pulse power supply 31, and bias FIG. 6 is a waveform diagram showing application timings of a substrate bias pulse signal from a pulse power supply 32. The application timing of the magnetic field deflection pulse signal by the deflection coil 21 with respect to the sputtering voltage V is the same as that of the first embodiment. The substrate bias pulse signal is turned on in synchronization with the on timing of the sputtering voltage V, and is turned off at the timing when a predetermined third period T3 has elapsed from the off time of the sputtering voltage V. The third period T3 is desirably in the range of 0 μsec to 30 μsec. This is because the plasma generated in the on period of the sputtering voltage V and the plasma remaining for a period of about 30 μsec from the off point of the sputtering voltage V are effectively attracted to the substrate 6. Further, by thus shifting the timing of the on period of the substrate bias pulse signal and the magnetic field deflection pulse signal, it is possible to minimize the interference of the operation caused by the respective signals. Therefore, in the sputtering apparatus of the second embodiment, the etching action of the gas particles attracted by the voltage application to the substrate 6 by the substrate bias pulse signal does not affect the deflection of the ionized particles due to the magnetic field, for example, Overhangs that occur in uneven portions such as trenches and holes are reduced, coverage on the sidewalls and bottom of the substrate recess is improved, and the thin film deposited by ion bombardment can be made more compact.

  According to the sputtering apparatus of the second embodiment of the present invention, it is possible to control the incident angle of the material particles ionized by the magnetic field deflection to the substrate 6 without impairing the stability of the plasma discharge. In addition, a bias voltage can be applied to the substrate 6 without affecting the deflection of the ionized material particles due to the magnetic field. Therefore, according to the sputtering apparatus and the sputtering method of the second embodiment, a dense, high-quality film can be stably formed with good coverage, on the substrate 6 having the uneven portion with a large aspect ratio. It becomes possible.

  As described above, according to the sputtering apparatus and the sputtering method of the present invention, as described in detail in each embodiment, the flying direction of the ionized particles is controlled to be deflected to an angle suitable for the concavo-convex shape of the substrate. It is possible to improve the coverage of the thin film. That is, in the sputtering apparatus and the sputtering method according to the present invention, coating of the bottom by an angle close to the vertical, coating to the side wall by control to a shallow incident angle, and control by reversing the incident angle Coating on the opposite side can effectively enhance the coverage. In addition, since the sputtering apparatus and the sputtering method of the present invention can apply the substrate bias without adversely affecting the deflection, for example, the overhang generated in the uneven portion such as the trench or the hole of the substrate is reduced, and the substrate concave portion The coverage of the bottom of the side wall can be further improved.

  Although the present invention has been described in each embodiment with some details, these configurations are exemplification, and the disclosed contents of these embodiments should be changed in the details of the configuration. In the present invention, substitution of elements in each embodiment, combination, and change of order can be realized without departing from the scope and spirit of the claimed invention.

  The sputtering apparatus and sputtering method according to the present invention are capable of stably forming, for example, a silicon nitride thin film with high coverage and high density, for a substrate having an uneven portion with a large aspect ratio. In the manufacture of devices, it is useful for forming high quality passivation thin films and the like.

Reference Signs List 1 vacuum chamber 2 pump 3 gate valve 4 gas supply source 5 substrate holder 6 substrate 7 target material 8 backing plate 9 magnet 10 yoke 20 substrate rotation mechanism 21 deflection coil 30 sputtering pulse power supply 31 deflection coil pulse power supply 32 bias pulse power supply 40 pulse timing Controller

Claims (4)

A sputtering apparatus comprising: a vacuum chamber in which a target material and a substrate are disposed; and a sputtering pulse power source connected to the target material, wherein plasma is generated in the vacuum chamber to form a thin film on the substrate. ,
The sputtering apparatus includes a deflection coil disposed in a space between the target material and the substrate, a deflection coil pulse power supply connected to the deflection coil, the sputtering pulse power supply, and the deflection coil pulse power supply. And a pulse timing controller connected to control the timing of each pulse from the sputtering pulse power source and the deflection coil pulse power source to be synchronized or shifted.   A bias pulse power supply connected to the substrate, the sputtering pulse power supply, the deflection coil pulse power supply, and the bias pulse power supply are connected to each other from the sputter pulse power supply, the deflection coil pulse power supply, and the bias pulse power supply. 2. The sputtering apparatus according to claim 1, further comprising: a pulse timing controller that performs control to synchronize or shift the timing of the pulse. A sputtering method using the sputtering apparatus according to claim 1 or 2, wherein
The pulse timing controller performs control such that the on timing of the pulse of the deflection coil pulse power supply is turned on after a lapse of a period of 0 μsec or more and 100 μsec or less from the off time of the pulse of the sputter pulse power supply. Sputtering method. A sputtering method using the sputtering apparatus according to claim 2, wherein
The pulse timing controller applies the on timing of the pulse of the bias pulse power in synchronization with the on of the pulse of the sputtering pulse power, and the off timing of the pulse of the bias pulse power corresponds to the sputtering pulse power. The sputtering method is characterized by performing control to turn off after a lapse of a period of 0 μsec or more and 30 μsec or less from the point of time when the pulse is off.

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