JPH04130626A - Semiconductor element manufacturing equipment - Google Patents

Abstract

PURPOSE:To alleviate a field which is generated on a substrate for a semiconductor element for preventing an insulated film from being damaged by the field by controlling the potential by a potential control device so that the front surface and rear surface of the semiconductor which is brought into contact with a conductor may be at the same potential. CONSTITUTION:When the ion beam is cast on a wafer 1 which is secured by a clamper 3 on a wafer support rest 2 which is placed on a turn table 5, the potential at the front surface of the wafer 1 rises in a moment and there appears a difference in potential between the front surface and rear surface of the wafer 1 because the support rest 2 is connected directly to the earth potential through the turn table. However, since the support rest 2 is connected to the earth potential through a resistance 4, the rear surface of the wafer 1 immediately gets electrified like the front surface and thus a difference in potential between the front and rear surfaces of the wafer 1 is reduced. Consequently, a field which is generated on the wafer 1 can be alleviated and an insulated film is prevented from being damaged.

Description

[Detailed Description of the Invention] [Summary] An object of the present invention is to provide a semiconductor device manufacturing device that alleviates an electric field generated on a substrate of a semiconductor device and prevents damage to an insulating film. In a semiconductor device manufacturing apparatus that irradiates charged particles onto a substrate of a semiconductor element supported by a substrate supporting means that supports a substrate, the substrate supporting means has at least a portion in contact with the substrate formed of a conductor, and the surface of the substrate,
A potential control means is provided for controlling the potential of the conductor so that the potential of the conductor and the back surface thereof are the same potential.

[Industrial application field]

The present invention relates to a semiconductor element manufacturing apparatus, and more particularly, to a semiconductor element manufacturing apparatus for manufacturing semiconductor elements, which is suitable for use in the field of manufacturing LSIs and the like.

In recent years, with the increase in density and definition of semiconductor devices, semiconductor device manufacturing equipment that can perform fine processing by irradiating charged particles such as ions and plasma has become popular in the manufacturing of semiconductor devices. Many have been developed.

For example, this involves irradiating a wafer with charged particles in order to control the amount of impurity doping through ion implantation, or to form a thin film on the wafer as a substrate using plasma. In recent processes, the temperature and dryness are progressing, making it easy for wafers to become electrically charged.

Since electrification of the wafer adversely affects the reliability of the element, it is necessary to prevent electrification.

[Conventional technology]

Conventional semiconductor device manufacturing equipment of this type includes, for example,
There is something like the one shown in Figure 4.

The semiconductor device manufacturing apparatus is roughly composed of a wafer support stand 2 as a substrate support means for supporting a wafer 1, which is a substrate of a semiconductor device, and a clamper 3.

The wafer 1 is, for example, a crystal of silicon Si or the like cut into thin pieces and subjected to an oxidation treatment or a diffusion treatment, and a circuit such as an LSI is printed onto the wafer 1.

The wafer support 2 holds the wafer 1 horizontally, and the wafer 1 is fixed on the wafer support 2 by the clamper 3.

In the above configuration, when doping the wafer l by, for example, ion implantation, this step is generally performed as follows.
Dopan) The wafer support table 2 and the clamper 3 are placed in a low temperature and dry state to control the 1 degree distribution, etc.
Ion implantation is performed by irradiating ions, which are charged particles, with a predetermined acceleration energy from above the wafer 1, which is firmly fixed.

[Problem to be solved by the invention]

However, in such conventional semiconductor device manufacturing equipment, charged particles are irradiated onto the wafer l in a low temperature and dry state, so as shown in FIG. There was a problem in that the potential on the front surface and the potential on the back surface of the wafer 1 were different, an electric field was generated in the insulating film on the front surface of the wafer 1, and the insulating film such as an oxide film was damaged by radiation.

This poses a problem in terms of long-term reliability of semiconductor devices.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a semiconductor device manufacturing apparatus that alleviates the electric field generated on the substrate of a semiconductor device and prevents damage to an insulating film.

[Means to solve the problem]

In order to achieve the above object, the semiconductor device manufacturing apparatus according to the present invention, as shown in the principle diagram in FIG. In a semiconductor device manufacturing apparatus that irradiates charged particles, the substrate supporting means 2 and 3 are small (both have portions in contact with the substrate 1 made of a conductor so that the front and back surfaces of the substrate 1 have the same potential). A potential control means 4 for controlling the potential of the conductor is provided in the conductor.

[Effect]

In the present invention, the potential of the conductor is controlled by the potential control means so that the potentials of the front and back surfaces of the substrate that are in contact with the conductor are at the same potential.

That is, the electric field generated on the substrate of the semiconductor element is relaxed, and damage to the insulating film due to the electric field is prevented.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings.

FIG. 3 is a schematic cross-sectional view showing an embodiment in which the semiconductor device manufacturing apparatus according to the present invention is applied to an ion implantation apparatus.

First, the configuration will be explained.

In FIG. 3, the same numbers as those attached to the principle diagram shown in FIG. 1 indicate the same parts.

The ion implantation apparatus, which is the semiconductor device manufacturing apparatus of this embodiment, can be roughly divided into a wafer support stand 2 and a clamper 3, which are substrate support means, a resistor 4, which is a potential control means, and a turntable 5. .

A wafer support stand 2 as a substrate support means for supporting a wafer 1 which is a substrate of a semiconductor element, a clamper 3, a resistor 4 as a potential control means, a turntable 5 on which the wafer support stand 2 and the clamper 3 are arranged. It consists of

The wafer support 2 of this embodiment is made of a metal conductor, and is firmly fixed onto the wafer support 2 by a clamper 3 while holding the wafer 1, which is a substrate of a semiconductor element, horizontally. There is.

The resistor 4 has one end connected to the wafer support 2 which is a conductor, and the other end connected to the ground potential via the turntable 5.

Note that the value of the resistor 4 is set in consideration so that the time constant τ between the wafer support stand 2 and the turntable 5 will be a value sufficiently smaller than the pulse period of the ion beam. That is,
The pulse width of the ion beam in this example is 1 tase
c, and the pulse period is 60 m5 ec, so the value of the resistor 4 is set so that the time constant τ between the wafer support stand 2 and the turntable 5 is, for example, lQmsec.

Next, the effect will be explained.

First, when the wafer 1, which is firmly fixed to the wafer support 2 on the turntable 4 by a clamper, is irradiated with an ion beam for ion implantation, the wafer support 2 is directly grounded via the turntable. Since the wafer 1 is connected to a potential, the front surface of the wafer 1 becomes a high potential instantaneously, and a potential difference is generated between the front surface potential and the back surface potential of the wafer 1.

However, unlike the conventional example shown in FIG. The potential difference between the surface and the back surface is reduced.

Therefore, the electric field generated on the wafer 1 can be relaxed, and damage to the insulating film can be prevented.

In addition, as in this embodiment, the time constant τ between the wafer support stand 2 and the turntable 5 is set to the pulse period of the ion beam (60
By setting the value of the resistor 4 to 10 m5ec, which is a sufficiently smaller value than Since there is no potential difference between the two and the two pulses are discharged before the next pulse arrives, repeated accumulation of charge can be prevented.

As described above, in this embodiment, by controlling the potential of the wafer support by the potential control means, the potentials of the front and back surfaces of the wafer of the semiconductor element can be controlled to be the same potential.

That is, the electric field generated on the substrate of the semiconductor element can be relaxed, and damage to the insulating film caused by this electric field can be prevented.

Therefore, reliability of the semiconductor device can be maintained for a long period of time.

Although the above embodiment has been described with reference to the case where it is applied to an ion implantation device, the present invention is not limited to this, and can also be applied to a device that has a step of irradiating charged particles, for example, a semiconductor device manufacturing device that performs plasma irradiation. Needless to say, there is.

〔Effect of the invention〕

In the present invention, by controlling the potential of the conductor of the substrate support means by the potential control means, the surface of the substrate of the semiconductor element,
It is possible to control the potentials of the two surfaces and the back surface to be at the same potential.

Therefore, the electric field generated on the substrate of the semiconductor element can be alleviated, and damage to the insulating film due to the electric field can be prevented.

[Brief explanation of drawings]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a schematic sectional view showing an embodiment in which the present invention is applied to an ion implantation device, and Fig. 3 is a diagram of the charge when an electric field acts on the wafer shown in Fig. 2. FIG. 4 is a cross-sectional view showing the configuration of a conventional example, and FIG. 5 is a diagram showing the distribution of charges when an electric field is applied to the wafer of FIG. 4. 1...Wafer (substrate), 2...Wafer support stand (substrate support means) 3...
... Clamper (substrate support means), 4 ... Resistor (potential control means), 5 ... Turntable. 42 A diagram showing the charge distribution when an electric field is applied to the wafer. 2. A cross-sectional view showing the configuration of the conventional example. figure

Claims (1)

[Scope of Claims] In a semiconductor device manufacturing apparatus that irradiates charged particles onto a substrate of a semiconductor device supported by a substrate support means for supporting a substrate of a semiconductor device, the substrate support means has at least a portion in contact with the substrate made of a conductor. 1. A semiconductor device manufacturing apparatus, comprising: a potential control means for controlling the potential of the conductor so that the front surface and the back surface of the substrate have the same potential.