JPS63262463A - Sputtering device - Google Patents

Abstract

PURPOSE:To always form thin films of a required thickness on the surfaces of samples by providing a means of estimating the rate of film formation from measured values of high frequency power and reactive power and controlling the time for film formation in accordance with the rate of film formation. CONSTITUTION:High frequency voltage from a high frequency power source 8 is impressed on the cathode 5 through a measuring part 7 and a matching unit 6 to generate plasma on the front side of a target 4 and thin films are formed on the surfaces of the samples 2. The measuring part 7 measures high frequency power and lost power and sends the measured values to a control part 9. The part 9 calculates effective power which contributes to sputtering from the measured values and sends a control signal for regulating the time required to form thin films of a desired thickness to the power source 8. Thus, thin films of the desired thickness can always be formed on the surfaces of the sample independently of a change in load impedance.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a sputtering apparatus, and in particular, in order to form a thin film on a predetermined sample surface in vacuum, a high frequency voltage is applied to a target to form a thin film on the sample surface. The present invention relates to a sputtering apparatus for forming thin films of conductive materials, insulating materials, etc.

[Conventional technology]

Conventionally, in this type of sputtering apparatus, the power output from a predetermined high-frequency power source is held constant, the impedance on the high-frequency power source side is matched with the impedance on the load side, and sputtering is performed in a state where power loss is minimized. The sputtering is completed after a predetermined period of time has elapsed.

[Problem that the invention seeks to solve]

In the conventional sputtering equipment described above, the sputtering time is set on the assumption that the impedance on the load side and the impedance on the high frequency power source side are always optimally matched, so the pressure in the discharge space and the residual If the load impedance changes due to the gas, the shape of the mechanism, etc., there will be a loss of high-frequency power from the time the load impedance changes until the time when the impedance on the high-frequency power supply side matches the load. becomes large, and the rate of thin film formation decreases. As a result, there is a drawback that the thickness of the thin film formed on the sample surface becomes thinner than a predetermined appropriate value during that period. This effect becomes more pronounced as the thin film formed on the sample becomes thinner.

[Failure to solve the problem]

The sputtering apparatus of the present invention includes a cathode having a target on its surface that is a material for a thin film formed on the surface of a predetermined sample, and a cathode located in front of the cathode so that the thin film forming surface of the sample faces the surface of the cathode. a holder for holding a sample so as to hold the sample; a high frequency power source for applying a predetermined high frequency voltage to the cathode; a measuring section for measuring high frequency power and loss power input to the cathode from the high frequency power source; A control unit extracts the thin film formation rate on the surface of the sample from the measured high frequency power and power loss, and controls the thin film formation time on the sample surface with reference to the thin film formation rate.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a conceptual block diagram showing the main parts of a first embodiment of the present invention. As shown in FIG. 1, this embodiment includes a vacuum container 1 having a vacuum exhaust port 10, a sample holder 3, a cathode to which a target 4 is fixed, and a matching box, corresponding to a sample 2. 6, a measuring device 6, a measuring section 7, a high frequency power source 8, and a control section 9.

In FIG. 1, the inside of the vacuum container 1 is evacuated through the vacuum exhaust port 10 by a separately prepared vacuum pump (not shown) until the pressure reaches about 10''3 Pa (Pascal), and then, A predetermined gas is introduced into the vacuum container 1, and the pressure in the vacuum container 1 is set at a pressure of about 1 to 10'' Pa.

In this state, the high frequency voltage generated in the high frequency power supply 8 is transmitted to the cathode 5 via the measuring section 7 and the matching box 5.
is applied to generate plasma in front of the target 4 fixed to the cathode 5. As a result, sample holder 3
A predetermined thin film is formed on the surface of the sample 2 held in the sample 2 . In this case, the matching box 6 functions to match the output impedance of the high frequency power source 8 with the impedance on the load side, and to minimize power loss from the high frequency power source 8.

On the other hand, the measuring section 7 measures the high frequency power output from the high frequency power source 8 and the power loss, and the respective power measurement values are sent to the control section 9 . In the control unit 9, the effective power contributing to sputtering is calculated from the measured values of the high frequency power and power loss, and the correlation between the effective power and the thin film formation rate determined in advance is determined. After the relationship is verified, a control signal is output and sent to the high frequency power source 8 to regulate the communication time of the high frequency power source 8, that is, the thin film formation time necessary to form a desired film thickness on the surface of the sample 1.

In the high frequency power source 8, generation of high frequency power is stopped in response to the input of the control signal, and the sputtering action is also stopped. Therefore, even if the impedance on the load side changes and the loss of high-frequency power becomes large and the rate of thin film formation on the surface of the sample 2 decreases, the thin film formation time can be controlled and adjusted via the control signal. , the thickness of the thin film on the surface of sample 1 is appropriately formed.

Next, a second embodiment of the present invention will be described.

FIG. 2 is a conceptual block diagram showing the main parts of the second embodiment. As shown in FIG. 2, in this embodiment, a vacuum container 1 having a vacuum exhaust port 10 and
It includes a sample holder 3, a cathode 5 to which a target 4 is fixed, a matching device 6, a measurement section 7, a high frequency power supply section 8, a control section 9, a drive section 11, and a shutter 12. .

In FIG. 2, the functions of the matching box 6, measuring section 7, high frequency power source 8, etc. are the same as in the first embodiment described above. The difference between this second embodiment and the first embodiment is that there is a drive section 11 that controls the position of the shutter 12 via a control signal input from a control section 9, and a gap between the sample 2 and the target 4. A shutter 12 is added. In the second embodiment, the means for controlling the operation time of the high frequency power source 8 in the first embodiment is used as a means for controlling the thin film formation time on the surface of the sample 2 in response to changes in impedance on the load side. In addition, the control unit 9
Means for controlling the position of the shutter 12 by the drive unit 11 and adjusting sputtering is also used via a control signal sent from the drive unit 11 .

[Effects of the Invention] As explained above, the present invention measures both the high frequency power output from a predetermined high frequency power source and the power loss,
By extracting the thin film formation rate on the surface of the sample from the measured values of both of the above-mentioned powers and controlling the thin film formation time with reference to the thin film formation rate, the pressure in the discharge section, the residual gas partial pressure, and the mechanical part can be controlled. This has the advantage that a desired film thickness can always be formed on the sample surface in response to changes in load impedance due to shape and the like.

[Brief explanation of drawings]

FIGS. 1 and 2 are conceptual block diagrams showing main parts of a first and second embodiment of the present invention, respectively. In the figure, 1...vacuum container, 2...sample 3...
Sample holder, 4... Target, 5... Cathode, 6
... Matching box, 7... Measuring section, 8... High frequency power supply,
9... Control unit, 10... Vacuum exhaust port, 11... Drive unit, 12... Shutter.

Claims (1)

[Claims] a cathode having a target on its surface that is a material for a thin film formed on the surface of a predetermined sample; and a cathode located in front of the cathode,
a holder for holding a sample such that the thin film forming surface of the sample faces the surface of the cathode; a high frequency power source for applying a predetermined high frequency voltage to the cathode; a high frequency power input to the cathode from the high frequency power source; A measuring section for measuring power loss; extracting the thin film formation rate on the surface of the sample from the high frequency power and the power loss measured in the measuring section; and calculating the thin film forming time on the surface of the sample with reference to the thin film forming rate. A sputtering apparatus comprising: a control section for controlling the sputtering apparatus.