JP2002252175A - Gas-phase stacking device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-phase stacking device which can improve coverage and embedding property, even if the aspect ratio of a recess is high, when stacking metal in the recess, such as a hole or the like provided at the topside of a substrate. SOLUTION: For a gas-phase stacker 1, a sputtering target 13 and a susceptor 15 are counterposed within a chamber 10 where a semiconductor wafer W is stored, and further an electrode pair 3 consisting of electrodes 3a and 3b is provided above the periphery of the susceptor 15. Moreover, electrodes 3a and 3b are connected to a power controller 4. This gas-phase stacker 1 applies pulse-form DC voltages at different voltage values to the electrodes 3a and 3b, when forming a sheed layer by sputtering metal from the sputter target 13. Hereby, an AC electric field is generated between the electrodes, and it becomes easy for sputtered ionic active seeds to reach the interior of the recess of the semiconductor wafer W, and biased to meandering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vapor deposition apparatus and method, and more particularly, to a vapor deposition apparatus and method for depositing a metal or a substance containing a metal on a substrate by a physical vapor deposition method.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a wiring when manufacturing a semiconductor device such as a memory element or a logic element, a trench, a contact hole serving as a conductive path between elements provided on a base such as a semiconductor wafer or the like is provided. After forming a barrier layer in a concave portion such as a through hole, a via hole, etc., for example, C
A method of forming a metal film containing u, Al or the like is widely used. Such a metal film is generally formed by physical vapor deposition (PVD) such as sputtering using a metal target.
Method, chemical vapor deposition (CV) using organic metal source as raw material
D) It is formed by a method or the like. Of these methods, P
The VD method is relatively advantageous from the viewpoints of excellent purity of the formed film, simplification of the device configuration, heat history on the semiconductor wafer, and the like.

[0003]

By the way, in recent years, ultra-L
2. Description of the Related Art As semiconductor elements such as SIs become more highly integrated, there is a tendency that miniaturization and multi-layering of electrode wiring layers and the like are further progressing. In a substrate on which such an element is formed, the aspect ratio of the concave portion becomes higher than ever, and an ideal multilayer electrode wiring structure having no steps is required as the number of layers increases. Was. On the other hand, when a metal is deposited in a concave portion having a high aspect ratio by the conventional PVD method, an overhang tends to occur easily in the opening portion of the concave portion. In some cases, the coverage was not sufficient, and it was difficult to obtain an element having desired electric characteristics.

Further, in order to eliminate such inconvenience, the pressure in the chamber in which the substrate is accommodated is reduced as much as possible, and furthermore, the geometrical arrangement between the metal target and the substrate is devised so that metal ions and the like can be eliminated. A method is conceivable in which the straightness of the sputtered particles is increased and metal ions or the like are easily introduced into the inner space of the concave portion. However, there is a possibility that sufficient coverage may not be obtained by this method depending on the arrest ratio and shape of the concave portion.

Further, as a base layer of the metal film, a method of forming a seed layer made of an extremely thin film of the same kind of metal on the barrier layer by a CVD method, and forming a metal film on the seed layer by a PVD method is also conceivable. However, in this method, although the wettability can be improved by the seed layer and the filling property of the concave portion can be improved, the process becomes complicated, and in some cases, a heat treatment step after the film formation is performed to improve the film characteristics of the seed layer itself. Etc. may be further required.

Accordingly, the present invention has been made in view of such circumstances, and when depositing a metal in a concave portion having a high aspect ratio provided on a substrate, the number of steps and the complexity of the steps are increased. It is an object of the present invention to provide a vapor-phase deposition apparatus and method capable of sufficiently improving the coverage and burying property of the concave portion without causing the formation of the gas-phase deposit.

[0007]

In order to solve the above-mentioned problems, a vapor deposition apparatus according to the present invention comprises (1) a chamber in which a substrate is accommodated, and (2) a chamber provided in the chamber to hold the substrate. A holding part and (3) a metal or a target provided in the chamber to face the holding part and containing a metal or a substance containing the metal, wherein the metal is deposited on the substrate by a PVD method. And (4) a plurality of electrodes provided in a space between the holding unit and the target in the chamber.

[0008] In the gas phase deposition apparatus configured as described above, a metal film or a film containing a metal is formed on a substrate by the PVD method. For example, when a process gas is supplied and the degree of vacuum is maintained in a state where the inside of the chamber in which the substrate is housed is evacuated to a predetermined degree of vacuum and a voltage is applied to the target, a glow discharge occurs in the chamber. A plasma is formed. The process gas is thereby dissociated to generate ionic species, and the ionic species collide with the target to sputter a metal or the like constituting the target. Active species such as metal ion species and metal atoms as sputtered particles move toward the substrate placed on the holding unit, reach the substrate, and are deposited, and eventually a metal film is formed. In the present invention, "active species" refers to ionic active species,
Shows those containing excited species such as radicals and neutral active species.

At this time, when, for example, a voltage having a predetermined polarity and a voltage value is applied to the plurality of electrodes provided in the space between the holding section and the target, an electric field is formed between the electrodes. Of the active species moving from the target toward the substrate, those having charges such as ions, when passing through this electric field, have their paths deflected according to the electric field strength and the charge and momentum or energy of the ions. Is done. Thereby, when a concave portion such as a via hole is provided on the base,
The ionic active species or the like may not enter straight in the depth direction of the concave portion, but may enter in an oblique direction, for example. Therefore, it becomes easy for the ionic active species to be incident so as to sufficiently reach the inner wall of the concave portion.

If the polarity of the voltage applied to the plurality of electrodes or the magnitude of the voltage value alternately changes at a predetermined time interval or period, an alternating electric field is generated between the holding portion and the target. obtain. In this case, the ionic active species from the target move toward the substrate in a meandering manner without moving in one direction. Therefore, it becomes easy to make the ionic active species obliquely enter the recess while maintaining the straightness of the active species as a whole.

More specifically, it is connected to a plurality of electrodes, and a first voltage is applied to at least one of the plurality of electrodes, and the other electrode is connected to the other electrode. It is preferable to further include a control unit that controls application of voltages to the plurality of electrodes so that a second voltage different from the first voltage is applied.

With this configuration, the difference (potential difference) between the two voltage values between the electrode to which the first voltage is applied and the electrode to which the second voltage is applied by the control unit is determined. A strong electric field is created. Therefore, by appropriately adjusting these voltage values, the ionic active species from the target can be adjusted according to the positional relationship between the target and the substrate in the chamber, the shape of the concave portion provided on the substrate, and other process conditions. Can be easily and easily deflected. At this time, the polarities of the first and second voltages may be the same or different, and the number of electrodes, their shapes, arrangement, and the like are not particularly limited. It is more preferable that the control unit independently controls the application of the voltage to each electrode.

Further, the control unit may control the first and second voltages to periodically change with respect to the plurality of electrodes, specifically, the polarity or the voltage of the first and second voltages. It is preferable to control the application of the voltage to the plurality of electrodes so that the magnitude of the value changes at a predetermined time interval or a predetermined cycle.

For example, if the first voltage is applied to one or some of the plurality of electrodes, and the second voltage is applied to the other electrodes, and these are alternately switched, the holding An alternating electric field can occur between the part and the target and between the electrodes, that is, above the substrate. Thereby, the above-mentioned progress state in which the ionic active species move in a meandering manner can be reliably exhibited.

Alternatively, first, a plurality of electrodes are arranged side by side around the base, these electrodes are arranged in a substantially annular shape, and a first voltage is applied to one or some of the electrodes, and the other electrodes are applied. Has a second
Is applied. Next, after a lapse of a predetermined time, when the second voltage is applied to the electrode to which the first voltage has been applied, the first voltage is applied to the adjacent electrode at the same time or almost simultaneously. By repeating such an operation sequentially for a plurality of electrodes arranged in an annular shape, an electric field in which the direction of the electric field changes at a constant period may be generated above the base on the holding unit. In this case, the ionic active species from the target is supplied onto the substrate while moving in a substantially spiral shape.

Still more preferably, the plurality of electrodes are provided so that an electric field having a maximum intensity within a range of 1 to 10 kV / m is formed between the plurality of electrodes. When the maximum intensity of the electric field is less than the lower limit, the path of the ionic active species tends to be hard to be sufficiently deflected, depending on the shape of the concave portion, process conditions, and the like. It is difficult to improve. On the other hand, when the maximum intensity of the electric field exceeds the upper limit, the ionic active species is excessively deflected, and the incident angle to the concave portion tends to be excessively large.

It is further preferable that the plurality of electrodes are applied with a pulsed DC voltage. In this case, when the electric field formed between the electrodes is an alternating electric field, the direction of the electric field is instantaneously or rapidly switched, and as a result, the direction of movement of the ionic active species can be easily controlled as desired. In addition, even in the case of a dynamic electric field in which the direction of the electric field changes periodically, there is an advantage that the switching of the electric field direction is smooth and sharp, and the spiral movement of the active species is easily achieved reliably.

Further, the vapor deposition method according to the present invention is a method effectively implemented using the vapor deposition apparatus of the present invention, wherein a metal or a metal is deposited on a substrate from a target containing the metal. A method for supplying an active species of a substance containing the metal and depositing the metal or a substance containing the metal.
An electric field is formed in a direction intersecting with a direction from the target toward the substrate. The electric field may be formed during the entire period or at least a part of the period during which the active species is supplied onto the substrate. It is preferable to carry out the process at an early stage of supplying on the substrate.

Generally, in deposition or film formation by the PVD method,
An electric field is formed between the target and the base, whereby active species such as metal ions and metal atoms emitted from the target are directed along the direction from the target toward the base, that is, a virtual perpendicular direction connecting the two. They tend to go straight. In many cases, the depth direction of the concave portion on the base is made to coincide with the perpendicular direction. Therefore, if an electric field is formed in a direction that intersects this direction, it is possible to appropriately deflect the incident angle of the ionic active species on the substrate, as described above.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. Note that the same components are denoted by the same reference numerals, and redundant description will be omitted. Unless otherwise specified, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

FIG. 1 is a configuration diagram (partly sectional view) schematically showing a preferred embodiment of a vapor phase deposition apparatus according to the present invention. The vapor deposition apparatus 1 includes a susceptor 15 (holding unit) that holds a semiconductor wafer W in a chamber 10 in which a semiconductor wafer W as a base is accommodated, and a sputter target 13 (target) at a position facing the susceptor 15. Are arranged. The chamber 10 is configured such that the above-described sputter target 13 fixed to a magnet 12 is coupled to an upper end portion of a housing 11 via an insulator 14. Also, the sputter target 13
The susceptor 15 is connected to a grounded high-frequency power source R for bias via a support mechanism 15a that can be driven up and down, while being connected to a grounded DC power source D.

Further, a clamp 16 for fixing the semiconductor wafer W is provided around the susceptor 15, and a shield 17 is further provided around the clamp 16.
The shield 17 is grounded to the same potential as the high-frequency power supply R and the DC power supply D. A reaction chamber 10a is defined inside the chamber 10 by the sputter target 13, the susceptor 15, the shield 17, and the like.

Further, the susceptor 15 has a heater 2
The semiconductor wafer W mounted on the susceptor 15 is heated by this.
The heater 2 is connected to a power supply (not shown), and a temperature sensor (not shown) for measuring the temperature of the semiconductor wafer W is provided inside the susceptor 15. Further, the process gas supply system 5 is connected to the chamber 10 via a pipe 51, and the exhaust system 6 having a vacuum pump (not shown) and the like is connected via a pipe 61. The inside of the chamber 10 is depressurized by the exhaust system 6, the inside of the reaction chamber 10 a is set to a predetermined decompressed atmosphere (degree of vacuum), and a process gas such as Ar gas is supplied from the process gas supply system 5 into the chamber 10.

Between the sputter target 13 and the susceptor 15 and above the clamp 16, two flat electrodes 3a and 3b constituting the electrode pair 3 are provided. Here, FIG. 2 is a cross-sectional view (partially omitted) showing a cross section taken along the line II-II in FIG. 1, and is a view showing an arrangement relationship between the semiconductor wafer W and the electrode pairs 3. As shown, electrode 3
a and 3b are installed facing each other substantially in parallel. The electrode 3
Although the constituent materials of a and 3b are not particularly limited,
It is preferable to use the same material as the material of the sputtering target 13. In this case, even if the electrodes 3a and 3b are sputtered by collision with the ionic active species, the semiconductor wafer W
a can be prevented from being contaminated with another kind of substance.

Returning again to FIG. 1, the vapor deposition apparatus 1
It has a power supply controller 4 (controller) to which the electrodes 3a and 3b are connected. The power supply control unit 4 includes a DC power supply 41 that outputs a pulsed DC voltage, and is connected to the DC power supply 41. The polarity, output value (pulse height), pulse width, and pulse interval of the voltage output from the DC power supply 41 , An output time, an output timing and the like.
In addition, the computer device 42 includes a calculation unit such as a CPU and an MPU, and an input unit connected to the calculation unit (both are not shown).

An example of the vapor deposition method according to the present invention using the vapor deposition apparatus 1 configured as described above will be described with reference to FIGS.
This will be described below with reference to FIG. FIG. 3 (A) to (C)
FIG. 4 is a process diagram showing a state in which a metal wiring layer is formed on a semiconductor wafer Wa (base) according to a preferred embodiment of the vapor deposition method according to the present invention. The semiconductor wafer Wa is
On the base layer 100, an insulating layer 101 made of a single layer or a multilayer of SiO ₂ or the like in which a concave portion H such as a trench or a hole is formed, and a barrier layer 1 is formed on the concave portion H and the insulating layer 101.
02 is formed.

The base layer 100 is made of silicon (Si)
Or Cu, Al, W in the case of multilayer wiring
And other layers made of a metal film. Further, as the barrier layer 102, Ta / TaN, Ti / TiN, WN
And the like. The semiconductor wafer Wa
Is obtained by previously performing degassing, adjusting an orientation flat, and removing an unnecessary film such as a natural oxide film formed on the surface, and then forming a barrier layer 102 on the surface. . In this embodiment, Cu, Al, W,
Alternatively, use is made of an alloy containing one of these metals.

First, the semiconductor wafer Wa shown in FIG.
Is placed at a predetermined position on a susceptor 15 in the chamber 10 shown in FIG. Then
After the exhaust system 6 is operated to exhaust the inside of the chamber 10 to a predetermined pressure (degree of vacuum), for example, Ar gas is supplied from the process gas supply system 5 into the chamber 10. Further, the heater 2 is operated to heat the semiconductor wafer Wa to a predetermined temperature.

The temperature of the semiconductor wafer Wa is monitored by a temperature sensor. When the temperature reaches a predetermined temperature, a predetermined DC voltage is applied to the sputter target 13 so that the sputtering target 13 has a positive predetermined potential, for example. Thereby, the Ar gas is dissociated by the glow discharge, and plasma is formed in the reaction chamber 10a. As a result, a metal or a substance containing a metal constituting the sputter target 13 is sputtered by Ar ions, Ar atoms, or the like in the plasma. At this time, the semiconductor wafer Wa and the susceptor 15 are negatively charged with respect to the plasma sheath. Further, by applying a high frequency power for bias to the susceptor 15, active species as sputtered particles are directed toward the semiconductor wafer Wa. Moving.

At this time, a pulsed DC voltage shown in FIGS. 4A and 4B is applied to the electrodes 3a and 3b from the power supply control unit 4, respectively. FIGS. 4 (A) and (B)
6 is a timing chart showing states of voltages output from power supply control unit 4 to electrodes 3a and 3b, respectively. As shown in the figure, the output voltage from the power supply control unit 4 is a pulsed DC voltage and has a substantially rectangular pulse waveform. In the case shown in the drawing, at an arbitrary time t0, a positive voltage (first voltage) and a negative voltage (second voltage) of a predetermined magnitude are applied to the electrodes 3a and 3b, respectively, , At each of the times t1 to t10, the electrodes 3a,
The polarity of the voltage to be applied to 3b is alternately switched.

That is, the power supply control unit 4 controls each electrode 3
a, 3b independently applied pulsed DC voltage, and
Control is performed so that an electric field is generated between the electrodes 3a and 3b such that the direction of the electric field alternates with time (in other words, the electric field changes at a predetermined time interval or period). That is, the electrodes 3a and 3b function as alternating electrodes, have a maximum intensity corresponding to the maximum potential difference between them, and have an alternating electric field substantially perpendicular to the direction from the sputter target toward the semiconductor wafer Wa. Occurs during 3b. In FIGS. 4A and 4B, drawing is performed until time t10 for convenience of illustration, but application of such a pulsed voltage is continued for an appropriate time.

FIG. 5 schematically shows a cross section taken along the line V--V in FIG. 2 in a state where the above-mentioned pulsed DC voltage is applied to the electrodes 3a and 3b while forming plasma in the chamber 10. FIG. As described above, by applying a DC voltage to the sputter target 13, the plasma P is formed below the sputter target 13, and the generated active species as sputtered particles move toward the semiconductor wafer Wa. Of these active species, those having charges such as ionic active species are periodically deflected in their courses by an alternating electric field generated between the electrodes 3a and 3b, and meander, for example, as schematically shown as an arrow E1 in the drawing. The wafer is supplied onto the semiconductor wafer Wa while changing the direction of movement.

The sputtered particles containing the ionic active species that proceed in this manner are deposited on the barrier layer 102,
A metal film is formed. Thus, the semiconductor wafer Wb on which the seed layer 103 made of the metal film is formed is obtained.
(B)). At this time, a part of the ionic active species is caused by an alternating electric field generated between the electrodes 3a and 3b, for example, as shown in FIG.
(B) enters the inside of the concave portion H in the direction indicated by the arrow E1. Thus, overhang near the opening of the concave portion is sufficiently suppressed, and the inner wall of the concave portion H is sufficiently covered with the metal film.

In the reaction chamber 10a, electrons are generated by the dissociation of the Ar gas by the plasma and the sputtering of the sputtering target 13, and the electrons are used for maintaining the plasma and also at the positive potential of the anode or the like. Quickly reach the charged part. Thereby, the semiconductor wafer Wa
Is prevented from being charged up.

Further, preferable film forming conditions in the step of forming the seed layer 103 include, for example, the following conditions. <Deposition conditions in the step of forming the seed layer 103> In-chamber pressure: Depends on the type of metal or a substance containing metal deposited on the barrier layer 102, but is preferably several mTorr or less. Deposition temperature: -50 To 500 ° C. Process gas: Ar, flow rate 0 to 300 ml / min (scc
m) Applied voltage to sputter target 13: -100 to-
1000V ・ Seed layer thickness: 20-5000Å ・ Maximum intensity of electric field generated between electrodes 3a, 3b: 1-10
kV / m

Here, the maximum intensity of this electric field is 1 kV /
If it is less than m, the path of the ionic active species tends to be not sufficiently deflected, although the degree varies depending on other film forming conditions, the shape of the chamber 10, and the like. In this case, it becomes difficult to make the metal ion species or the like incident on the concave portion H, particularly toward the inner side wall, and it becomes difficult to sufficiently cover the concave portion H with the seed layer 103. On the other hand, when the maximum intensity of the electric field exceeds 10 kV / m, the path of the ionic active species tends to be excessively deflected. In this case, the shift of the ionic active species from the depth direction (generally, the vertical direction) of the concave portion H to the concave portion H becomes excessive, and the ionic active species reaches the inner wall near the bottom of the concave portion H. It becomes difficult. In this case, in some cases, overhang may be easily caused.

Next, the electrodes 3a, 3b from the power control unit 4
The application of the pulsed DC voltage to the seed layer 103 is stopped.
The target metal is further sputtered onto the semiconductor wafer Wb on which is formed. The active species of the metal that has reached the semiconductor wafer Wb are deposited on the seed layer 103 and the seed layer 1
Since 03 is the same kind of metal film, the wettability is enhanced, and the metal deposited on the opening of the recess H or on the periphery thereof is easily moved into the inside. Thus, the semiconductor wafer Wc on which the metal wiring layer 104 in which the concave portion H is sufficiently buried with the metal is formed.

Here, suitable film forming conditions in the step of forming the metal wiring layer 104 include, for example, the following conditions. <Deposition conditions in the process of forming the metal wiring layer 104>-Pressure in the chamber: preferably several mTorr or less-Deposition temperature: 0 to 700 ° C-Process gas: Ar, flow rate: 0 to 300 ml / min (scc
m) Applied voltage to sputter target 13: -100 to-
1000V

According to the vapor deposition apparatus 1 configured as described above and the vapor deposition method of the present invention using the same, the electrode 3
A pulse-like DC voltage having a different voltage value is applied between the electrodes 3a and 3b, and the polarity and the voltage value are periodically changed. An alternating electric field is generated between 3b. Accordingly, the path of sputtered particles such as ionic active species of metal sputtered from the sputter target 13 can be periodically deflected, and the semiconductor wafer W
The ionic active species and the like sufficiently reach the inside of the concave portion H provided in a.

Accordingly, since the inside of the concave portion H can be sufficiently covered with the seed layer 103 made of a metal film, even when the aspect ratio of the concave portion H is high, overhang occurs when the metal wiring layer 104 is formed. Can be sufficiently suppressed, and the coverage and embedding of the concave portion H can be sufficiently improved.
In addition, since it is not necessary to combine other methods such as the CVD method, it is possible to prevent an increase in the number of processes and a complicated process. Further, since the electric field is an alternating electric field, the ionic active species can be advanced in a meandering manner without being biased in one direction. Therefore, the straightness of the active species as a whole can be maintained, and the active species can be sufficiently supplied onto the semiconductor wafer Wa.

Further, since the maximum intensity of the electric field between the electrodes 3a and 3b is set to 1 to 10 kV / m, it is easy to make the path of the metal ion species or the like incident on the concave wall H, particularly toward the inner wall, and it is easy to over-flow. The occurrence of hang can be further suppressed, and the coverage and embedding property can be further improved. Furthermore, the electrode 3
Since the degree of deflection of the ionic active species can be adjusted only by adjusting the potential difference of the voltage applied to a and 3b, the pulse width, the alternating period (interval between the times t0 to t10 shown in FIG. 3), etc. Shape and aspect ratio of recess H, seed layer 103
According to various conditions such as the film forming conditions of the
The coverage and embedding of the concave portion H can be optimized very easily.

Furthermore, since a pulsed DC voltage is applied to the electrodes 3a and 3b, the direction of the electric field of the alternating electric field formed between the electrodes 3a and 3b can be instantaneously or quickly switched. As a result, it becomes easier to control the direction and amount of movement of the ionic active species. Therefore, it is easy to adjust the degree of deflection of the ionic active species to a desired degree, so that it is possible to more reliably control the direction of incidence on the concave portion on the semiconductor wafer Wa. Can be further improved.

FIG. 6 is a plan view (partially sectional view) showing a main part of another embodiment of the vapor phase deposition apparatus according to the present invention. The vapor phase deposition apparatus according to the present embodiment uses, instead of the electrode pair 3,
It has the same configuration as the vapor deposition apparatus 1 shown in FIG. 1 except that it has an electrode section 7 composed of four electrodes 7a to 7d. Each of these electrodes 7a to 7d is formed in a flat plate shape, and is arranged annularly above the periphery of the semiconductor wafer W. That is, as shown, the electrodes 7a and 7c are provided so as to face each other, and the electrodes 7b and 7d are provided so as to face each other. Each of the electrodes 7a to 7d is connected to the power control unit 4 shown in FIG.

An example of the vapor deposition method of the present invention using a vapor deposition apparatus having such an electrode unit 7 will be described. Also in this case, the procedure for forming the seed layer 103 on the barrier layer 102 and forming the metal wiring layer 104 thereon using the semiconductor wafer Wa shown in FIG. The method of applying a voltage to the electrode unit 7 when depositing is different from the method described above. FIG. 7 (A)-
(D) is a timing chart showing states of voltages output from the power supply control unit 4 to the electrodes 7a to 7d, respectively.

As shown in the figure, the output voltage from the power control unit 4 is a pulsed DC voltage and has a substantially rectangular pulse waveform. First, from the power control unit 4, the time t0
In, a predetermined positive voltage (first voltage) is applied to the electrode 7a, and a predetermined negative voltage (second voltage) is applied to the other electrodes 7b to 7d. Next, at time t1, a positive voltage (first voltage) is applied to the electrode 7b and the other electrodes 7
A negative voltage (second voltage) is applied to a, 7c and 7d. Further, after time t2, the application of the positive voltage and the application of the negative voltage are similarly switched, that is, the positive potential is controlled to circulate around the semiconductor wafers W and Wa with the passage of time.

As a result, an electric field is generated above the semiconductor wafer Wa so as to be substantially orthogonal to the direction from the sputter target 13 toward the semiconductor wafer Wa and to change the direction of the electric field at regular intervals. Here, FIG.
FIG. 4 is a perspective view schematically showing a state in which an ionic active species proceeds in such an electric field generated inward. As shown in the drawing, among the active species as the sputtered particles emitted from the sputter target 13 (see FIG. 1), the ionic active species or the like having a charge change in the direction of movement so that its path is substantially spiral. Therefore, even when the recess H (see FIG. 3) provided in the semiconductor wafer Wa is surrounded on all sides by the inner walls, the ionic active species can be sufficiently reached on each inner wall to be easily deposited. Become. Accordingly, even when the concave portion H has a high aspect ratio, the metal wiring
The coverage and embedding of the concave portion H can be remarkably improved.

Also in the present embodiment shown in FIG. 6, the maximum intensity of the electric field generated inside the electrode portion 7 is 1 to 10 kV / m.
By doing so, it becomes easy to make the path of the ionic active species incident on the inner wall of the concave portion H easily, and it is possible to further suppress the occurrence of overhang at the opening portion of the concave portion H or its peripheral portion,
The coverage and embedding of the recess H can be further improved.
Further, since the voltage applied to the electrodes 7a to 7d is a pulsed DC voltage, the switching of the electric field direction can be performed smoothly and sharply. Therefore, rotation in the direction of the electric field can be suitably performed, and the helical movement of the ionic active species can be surely developed.

Further, the rotation period in the direction of the electric field depends on the electrode 7a.
7d, the pulse width of the positive voltage and / or the negative voltage, and the time interval between the positive voltages (for example, the time width between times t0 and t4 shown in FIG. 7) are adjusted.
It can be easily controlled. Therefore, the degree of deflection of the ionic active species can be easily adjusted, so that the coverage of the concave portion H depends on various conditions such as the shape and aspect ratio of the concave portion H, the film forming conditions of the seed layer 103, and the shape of the chamber 10. It is extremely easy to optimize the embedding property.

In each of the above-described embodiments, a coherent plate may be provided in the reaction chamber 10a in the chamber 10. In addition, electrode pair 3
The voltage application to the electrode unit 7 does not necessarily need to be performed in the entire period (time) during the formation of the seed layer 103, and may be performed in a part of the period, and is preferably performed at least at the beginning. . Further, the electrode pair 3 and the electrode portion 7
The DC voltage applied to each of the electrodes 3a, 3b, 7a to 7d may be not pulse-shaped, may have a pulse waveform other than a rectangular wave, or may be an AC voltage.

Further, the application of the voltage to the electrodes 7a to 7d is not limited to the control in which the electric field rotates as shown in FIG. 7, and for example, a positive voltage is applied to the electrodes 7a and 7b.
At this time, a negative voltage may be applied to the electrodes 7c and 7d, and these may be switched alternately. In this case, an alternating electric field is generated. Alternatively, two electrodes facing each other among the four electrodes may be used as the alternating electrodes.

Further, first, a first voltage is applied to the electrode 7a and a second voltage is applied to the opposing electrode 7c.
Next, the application of the voltage to the electrodes 7a and 7c is stopped, the first voltage is applied to the electrode 7b adjacent to the electrode 7a, and the second voltage is applied to the electrode 7d facing the electrode 7a. Next, the application of the voltage to the electrodes 7b and 7d is stopped, and the first voltage is applied to the electrode 7c adjacent to the electrode 7b and the second voltage is applied to the electrode 7a facing the electrode 7b. Then, electrode 7
The voltage application to the electrodes 7c and 7a is stopped, and the first voltage is applied to the electrode 7d adjacent to the electrode 7c, and the second voltage is applied to the electrode 7b facing the electrode 7c. Such operations may be sequentially switched. This also generates an electric field in which the direction of the electric field rotates.

In addition, not only when the seed layer 103 is formed but also when the metal wiring layer 104 is formed, the electrode pairs 3 or the electrode portions 7 are formed.
May be applied. Also, the electrodes 3a, 3b, 7a
It is not always necessary to change the polarity of the voltage applied to 〜7d, as long as a potential difference that can significantly generate an electric field between the electrodes is achieved. For example, the lowest voltage (base voltage) of the pulse voltages shown in FIGS. 4 and 7 may be set to 0 (zero).

Further, the number and arrangement of the electrodes are not limited to those shown in the drawings. FIG. 9 is a plan view (partially sectional view) illustrating still another electrode arrangement in the present invention. In the figure, the electrode section 8 is composed of eight plate-like electrodes 8a to 8h arranged in a ring above the periphery of the semiconductor wafers W and Wa. The use of such an electrode section 8 allows smoother rotation in the electric field direction and further fine adjustment of the rotation cycle. Therefore, the deflection of the ionic active species traveling in the electric field can be controlled more accurately.

[0054]

As described above, according to the vapor deposition apparatus and method of the present invention, a plurality of substrates provided between a holding portion of a substrate such as a semiconductor wafer and a metal-containing target such as a sputter target are provided. By applying a voltage to the electrodes to form an electric field, it is possible to deflect the course of the active species as sputtered particles as desired. Therefore, when depositing metal in a concave portion having a high aspect ratio provided on a base, it is possible to sufficiently improve the coverage and the embeddability of the concave portion without increasing the number of steps and complicating the steps. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram (a partial cross-sectional view) schematically illustrating a preferred embodiment of a vapor deposition apparatus according to the present invention.

FIG. 2 is a sectional view (partially omitted) showing a section taken along line II-II in FIG.

FIGS. 3A to 3C are process diagrams showing a state in which a metal wiring layer is formed on a semiconductor wafer by a preferred embodiment of a vapor deposition method according to the present invention.

FIGS. 4A and 4B are timing charts showing states of voltages output from the power supply control unit to the electrodes.

FIG. 5 is a plan view schematically showing a cross section taken along line VV of FIG. 2 in a state where a pulsed DC voltage is applied to electrodes while forming plasma in a chamber.

FIG. 6 is a plan view (partially sectional view) showing a main part of another embodiment of the vapor deposition apparatus according to the present invention.

FIGS. 7A to 7D are timing charts showing states of voltages output from the power supply control unit to the electrodes.

FIG. 8 is a perspective view schematically showing a state in which an ionic active species advances in an electric field generated inside an electrode portion.

FIG. 9 is a plan view (partially sectional view) illustrating still another electrode arrangement according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas phase deposition apparatus, 3 ... Electrode pair, 4 ... Power supply control part, 3
a, 3b, 7a to 7d, 8a to 8h: electrode, 7, 8, electrode part, 10: chamber, 13: sputter target (target), 15: susceptor (holding part), 100: base layer, 102: barrier layer, 103: seed layer; 104: metal wiring layer; H: concave portion; W, Wa: semiconductor wafer (substrate).

Continued on the front page (72) Inventor Koji Hara 14-3, Shinzumi, Narita-shi, Chiba Pref. In Nogedaira Industrial Park Applied Materials Japan Co., Ltd. F-term (reference) 4K029 AA06 AA29 BD01 CA03 DC03 DC04 DC28 DC34 DC35 EA09 4M104 AA01 BB02 BB04 BB14 BB17 BB18 BB33 CC01 DD16 DD38 DD39 FF13 FF17 FF18 FF22 HH00 HH13 5F033 HH08 HH09 HH11 HH12 HH18 HH19 HH21 HH32. WW00 XX02 XX04 5F103 AA08 BB14 BB42 BB52 DD28 HH03 NN10 RR10

Claims (6)

[Claims] An apparatus includes: a chamber in which a substrate is accommodated; a holding unit provided in the chamber for holding the substrate; and a target provided in the chamber to face the holding unit and including a metal. A vapor deposition apparatus for depositing the metal or a substance containing the metal on the substrate by a physical vapor deposition method, wherein the vapor is deposited in a space between the holding unit and the target in the chamber. A vapor phase deposition apparatus comprising a plurality of provided electrodes. 2. The first electrode is connected to the plurality of electrodes so that a first voltage is applied to at least one of the plurality of electrodes, and the first voltage is applied to another electrode. The vapor deposition apparatus according to claim 1, further comprising a control unit that controls application of voltages to the plurality of electrodes so that a second voltage different from the second voltage is applied. 3. The control unit controls application of voltages to the plurality of electrodes so that the first and second voltages periodically change with respect to the plurality of electrodes. 3. The vapor deposition apparatus according to claim 2, wherein: 4. The plurality of electrodes are provided such that an electric field having a maximum intensity within a range of 1 to 10 kV / m is formed between the plurality of electrodes. The vapor phase deposition apparatus according to any one of claims 1 to 3. 5. The method according to claim 1, wherein the plurality of electrodes are applied with a pulsed DC voltage.
The vapor-phase deposition apparatus according to any one of Claims 4 to 5. 6. A vapor-phase deposition method for supplying an active species of the metal or a substance containing the metal from a target containing the metal on a substrate to deposit the metal or the substance containing the metal, When supplying the active species onto the substrate, an electric field is formed between the substrate and the target in a direction intersecting a direction from the target toward the substrate. .