JPH0733174B2 - Wafer transfer robot - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a wafer transfer robot,
In particular, the present invention relates to a semiconductor manufacturing wafer transfer robot that operates in a clean room.

[0002]

2. Description of the Related Art In FIGS. 2 and 3, 1 is a wafer transfer robot, 2 is a rotating drum thereof, 3 and 4 are mutually connected arms each having a built-in drive motor, and 5 is a finger fixed to the tip of the arm 4. A wafer holding portion 6 is formed at the tip of each finger 5.

DRAM, which has been a driving force for high integration in the semiconductor industry, is about to enter a full-scale mass production system of 4 Mbits. Wafers used for such semiconductor manufacturing are generally processed in a clean room, but it is considered that control of pollutants in various forms such as particles, gases, and ions will become more severe in the future. Among these pollutants, many theoretical and experimental studies have been conducted in the fields related to particle deposition. As one of the results of these studies, it has been clarified that the electrostatic force particularly contributes to the deposition of particles of submicron or smaller.

The sources of these fine particles are as follows:
With the progress of automation in the clean room, the clean room itself and the human body are changing to manufacturing equipment. Many semiconductor manufacturing apparatuses operate under reduced pressure, and the rapid pressure drop and adiabatic expansion of the reaction gas promotes particle growth and deposits on the inner wall of the apparatus. Due to the imbalance of the pressure when the gate is opened, not only the wafer in the apparatus but also the wafer in the vicinity of the apparatus during transportation may be contaminated with particles.

[0005]

In the semiconductor manufacturing as described above, the inside of the clean room is cleaned by using the ULPA filter. However, in the semiconductor manufacturing, it is generated from the wafer transfer robot and its drive motor.
At present, no effective method has been proposed as a method for suppressing particle deposition of 1 μm to 0.1 μm, particularly about 0.3 μm, which is harmful to the wafer. The present invention aims to achieve the above needs.

In the wafer transfer robot of the present invention, the wafer holding portion on which the semiconductor manufacturing wafer is placed is a metal plate.
Then, attach a heater to the lower surface of this metal plate and
Attach the grounding metal plate through the electrically insulating plate, and
The wafer is placed on the ground metal plate, which accounted become about 10 ° C. higher temperature than the ambient temperature by heating the wafer, web
Prevents particle deposition of 1 μm to 0.1 μm and charge
The feature is that it can be stopped .

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

As a result of various experiments and studies, the present inventor has found that the deposition of the particles can be suppressed by heating the wafer above the ambient temperature by about 10 ° C. or more.

[0009] The present invention was made based on the experimental results, the wafer holding portion 6 as shown in FIG. 1 in the present invention, the metal plate 7 such as aluminum, the metal plate 7 A heater 8 such as a silicon rubber heater attached to the lower surface of the metal plate 7 and an electrically insulating plate 9 on the upper surface of the metal plate 7.
And a metal plate 10 for grounding placed via the above, and when a wafer is placed on the metal plate 10 for grounding, the wafer is about 10 ° C. above the ambient temperature, preferably 20 ° C.
In addition to being able to heat at a high temperature of 30 ° C., the metal plate 10 for grounding is grounded so that the charge on the wafer can be removed.

The particle deposition inhibiting effect in the present invention was confirmed by the following experiments.

A sheet-like beam of an Ar laser (output 4 W) was irradiated onto the surface of the wafer at an angle of about 7.3 °, and the particles were visualized by the forward confusion light of the particles reaching near the surface. The behavior of these visualized particles was recorded on a VTR through a camera incorporating an image intensifier, and the particle deposition number and distribution on the wafer surface were measured. The particle concentration is KC at a position 0.01 m directly below the generating nozzle.
-01A (Made by Rion: suction flow rate 5 × 10 ^-4 m ³ / mi
n. ), And converted into the concentration on the wafer surface later.

The detection limit of particles by the laser visualization method is about 0.3 μm, and the effect of preventing the deposition of particles smaller than this was not confirmed, but if fluorescence analysis using fluorescent particles is used, it is 0.3 μm or less. It seems that the particle deposition prevention effect of is also clarified.

[0013]

Since the wafer transfer robot of the present invention is constructed as described above, heating the wafer by the heater 8 causes the wafer transfer robot and its drive motor to generate 1 μm which is harmful to the wafer.
There is a great advantage that particle deposition of about 0.1 .mu.m, particularly about 0.3 .mu.m can be effectively prevented and, if necessary, the charge generated on the wafer can be removed to improve the particle deposition inhibiting effect.

[Brief description of drawings]

FIG. 1 is a detailed cross-sectional view of a wafer holding unit of a wafer transfer robot of the present invention.

FIG. 2 is a front view for explaining a wafer transfer robot.

FIG. 3 is a plan view of a finger portion of a wafer transfer robot.

[Explanation of symbols]

 1 Wafer Transfer Robot 2 Rotating Drum 3 Arm 4 Arm 5 Finger 6 Wafer Holding Part 7 Metal Plate 8 Heater 9 Insulating Plate 10 Metal Plate for Grounding

Claims (1)

[Claims] 1. A metal plate is used as a wafer holder for mounting a semiconductor manufacturing wafer, and a heater is attached to the lower surface of the metal plate.
And attach a grounding metal plate to the top surface through an electrically insulating plate.
After mounting, the wafer is placed on this grounding metal plate, the wafer is heated to a temperature higher by about 10 ° C. than the ambient temperature , and particles of 1 μm to 0.1 μm are added to the wafer.
A wafer transfer robot characterized by being able to prevent child deposition and electrification .