JPH0456765A - Method for controlling wafer temperature - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the oii* and Kii degree profiles of a wafer during processing in a wafer processing apparatus for forming and etching thin films of semiconductors and the like.

[Conventional technology]

The conventional Que temperature control device is disclosed in Japanese Patent Application Laid-Open No. 6386168.
As described in the publication, a heating element and a cooling channel are provided in the wafer placement section, and argon gas is introduced into the portion of the placement section that is in contact with the back surface of the wafer. The temperature of the wafer was controlled so that it was close to the temperature of the wafer platform by conducting conduction. The storage area is a cooling waterway.

Since it has a cooling water inlet, an argon gas inlet, etc., there is no mass, and it takes time for the loaded part to rise to a predetermined temperature. Nine, to cool down the wafer while it is being heated,
In order to cool the heating element (turn off the O heating means), and then flow cooling water into the cooling waterway from the cooling water inlet,
It takes a considerable amount of time for the wafer platform to cool down.

Therefore, since the wafer tin salting time in the wafer rounding device is about 1 to 2 minutes in the single wafer type, it has been impossible to control the temperature profile of the wafer from heating to cooling during embedding.

[Problem to be solved by the invention]

The above conventional technology takes into consideration the mass of the rounding temperature control block (wafer mounting part) for heating and cooling the wafer and the time constant until the heating and cooling temperature reaches the set temperature. There was a problem that the changer temperature profile control could not be followed.

An object of the present invention is to change the temperature of a wafer in a wafer iodide apparatus within a short time or to set it to a predetermined temperature.

Another object of the present invention is to control the temperature of the wafer during processing to a predetermined temperature profile from the beginning to the end of the process.

[Means to solve the problem]

Ninthly, in order to achieve the above object, the present invention reduces the mass of the temperature control block for heating and cooling provided on the backside of the wafer, and furthermore, in order to instantly switch between heating and cooling, the heating element and the cooling element are A Berthier element is used in which both can be used in the same element, and by switching the direction of current, it is possible to switch the surface of the temperature control block in contact with the back side of the wafer I from a heating surface to a cooling surface.

Furthermore, the wafer mounting section of the present invention has a large mass compared to the wafer, and has a temperature control block consisting of a pace block and a Berthier element that perform long-term temperature control, and a wafer mounted on the temperature control block. Means were provided to allow heat transfer to and from the temperature control block in a vacuum.

[Effect]

The temperature control block of the wafer platform is composed of a Peltier element, so if a current is passed through the Peltier element, for example in the forward direction, the surface of the temperature control block that contacts the wafer Kll is heated and comes into contact with the opposite base block IIc. The surface is cooled. Since the mass of the pace block differs by more than two orders of magnitude compared to the wafer, the temperature of the pace block will vary by only a few places with the amount of heat required to heat the wafer to 100 degrees Celsius, and conversely, the temperature of the wafer will vary by several hundred degrees Celsius. In order to cool this, the surface in contact with the wafer is cooled by flowing C)'fllN in the opposite direction to the Berthier element of the temperature control block, and the wafer is cooled by absorbing the amount of heat from the wafer. In this case, as in the case of heating, the amount of heat flowing into the pace block side is almost the same as the pace block! l! However, when a large number of wafers are continuously heated or cooled to control the temperature of the wafer, the temperature of the pace block continues to cool or heat, and the temperature control function of the Berthier element decreases. Therefore, the pace block should be equipped with a heating source and cooling function. In addition, most of the wafer processing is performed under reduced pressure (10-2Pa to 102Pa
Since the process is carried out in a vacuum region of i degrees Celsius), a gas introduction mechanism is installed on the surface of the temperature control block in contact with the wafer to transfer heat through the gas, or an electrostatic adsorption function is installed on the surface of the temperature control block in contact with the wafer. , improving heat transfer between the temperature control block and the wafer.

Due to this effect, the temperature of the wafer during wafer processing in vacuum can be controlled in a short time, and the temperature can also be controlled from heating to cooling or from cooling to heating in a short time.

[11 Practical Examples] Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1st
The diagram shows wafer processing equipment! As a sputtering device! A cathode structure 2 for sputtering and a wafer mounting section 3 are installed in a vacuum vessel 1 having a process gas CI [&, and an exhaust hand R (not shown). Plus on the cathode structure 2Fi target 11! It has a magnetic device 4 to confine the magnetic device 4Fi yoke 13.
It consists of a magnetic coil 14 and its power source 15, and is installed on a backing plate 116 having a target 11 opposite the CI target 110. The cathode structure 2 is installed in a vacuum container 1 in an electrically floating state via an insulating plate 17, and an anode 18 is installed in the vacuum container near the target 11. The anode 18 and the backing plate 16 of the cathode structure 2 A sputtering power supply 19 is installed at the junction. Wafer placement section 3Fi, pace block 2
The temperature control block 21 and the temperature control block 21 are wired to improve heat conduction, and the zero-loss plate 22 installed on the mounting plate 22 is connected to the vacuum vessel 1Y through an insulating plate 23 in an electrically floating state. will be installed. The base block 20 includes a heater 24 for heating, a power source 25 thereof, a water channel 26 for cooling, and an inlet 27 and an outlet 28 for introducing cooling water into the water channel 26. Further, the temperature control block 21 is connected to an O power source 29 for the Perteini element, and is provided with a gas introduction port 31 for introducing gas to the back surface of the wafer 50. Further, a presser foot 32 is installed on the upper surface of the wafer 50 to bring the wafer 30 into close contact with the temperature control block 21 when gas is introduced to the back surface of the sea urchin I-.・Atmosphere gas in plasma on the surface (
A bias power source 33 is connected which causes ions (generally argon gas) to enter and collide.

With this configuration, when performing bias sputter film formation in which atmospheric gas ions collide with the wafer surface during sputter formation, in normal O film formation, the Ueno film is heated to a predetermined temperature fLK before film formation.
It is heated and supplied to the wafer holder. After that, to perform bias sputtering film formation, atmospheric gas ions collide with the wafer, and this energy is generally several tens to several hundred W, and as the wafer progresses, the i! As the temperature rises, LSI distribution a
The temperature is 450°C or higher, which is the permissible greenhouse temperature for m-formation. For this reason, in this type of film formation, the wafer mounting section must be cooled.
Prevents the temperature of the wafer from rising. However, in such a structure, if a heated wafer is supplied to the wafer platform at a predetermined temperature IIL before film formation, the wafer O temperature will drop because the wafer platform has been cooled, and the initial temperature of film formation will decrease. When the straw was formed, the temperature dropped below the required temperature and high quality straw could not be obtained.

In the present invention, the back side 11rK of the wafer 30 is provided with a temperature control block incorporating a Pelty element (not shown). The direction of the current flowing through the Berthier confectionery is switched at the start of bias sputtering, and the surface of the L degree control block 21 in contact with the wafer 50 is cooled to a low temperature state 11.

According to this embodiment, the wafer can be controlled to a predetermined temperature or temperature profile from heating to cooling and from heating to cooling and from cooling to heating from the initial stage of film formation through the member, and a high quality film can be formed. I can do it.

Another embodiment of the present invention will be described with reference to FIG.

Figure 2 shows that the sea urchin I/Ueno/mounting part of the processed lid is different from that in Figure 1. waterway 2
A base block 20 is provided with a cooling water inlet 27 and an outlet 28 for cooling water into the water passage 26, and a temperature control block 40 is installed in the base block 20 with good thermal conductivity. The temperature control block 40 is equipped with a Peltier element, to which the power source 29 is connected, and furthermore, an electrostatic adsorption electrode 41 having a high dielectric constant insulating thin film on a conductor is connected to the wafer backside. are installed in a thermally conductive and electrically insulated manner. Further, another cylindrical electrostatic adsorption electrode 42 is arranged on the outer periphery of the temperature control block 40, and the electrode 4
A power source 43 for attraction is connected to the electrostatic attraction electrode 42 and the electrostatic attraction electrode 42 . In addition, a contactor 44 and an insulator source 53 for applying a bias voltage to the wafer 30 are installed. According to the second embodiment, the wafer 30 and the mx control block 40
Electrostatic adsorption electrode 41゜4 to improve heat transfer efficiency with
2, the introduction of the gas shown in the first embodiment becomes difficult, and aX control in a high vacuum region becomes possible.

〔Effect of the invention〕

According to the present invention, it is possible to control the temperature of the wafer being processed in the vacuum of the wafer processing apparatus to a predetermined temperature t during the wafer processing time, and the temperature profile of the wafer can be controlled as the wafer processing progresses. The crystallinity! i1. Secretly! It can improve the township and form high-quality catches.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a wafer processing apparatus according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a wafer loading section according to another embodiment of the present invention.7 1... Vacuum vessel; 2-・Cando structure, 5.3′・
. . . Wafer placement unit, 20 . . . Base block, 21.
40... Temperature control block, 30... Wafer 41
, 42... Electrostatic adsorption electrode. 15\

Claims (3)

[Claims] 1. A wafer temperature control method characterized in that a Peltier element is used to control the temperature of a processed wafer in a wafer processing apparatus. 2. A wafer temperature control method characterized in that temperature control when processing a wafer in a vacuum atmosphere is performed by introducing gas into the Peltier element and the back surface of the wafer to increase the amount of heat for heating or cooling the Peltier element. 3. 3. The method of controlling wafer temperature according to claim 2, using electrostatic adsorption for heat transfer between the Peltier element and the wafer.