JPS6112674Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is used to hold a semiconductor wafer at a predetermined position and tilt at a desired position in a furnace core tube for purposes such as heat treatment, diffusion, thin layer growth, etc. The present invention relates to a wafer holder.

(Prior art and its problems) Generally, the gas flow within the furnace core tube is not necessarily uniform, but is often unevenly distributed when viewed from the cross-sectional direction of the furnace core tube.

When wafer processing is performed under such gas flow conditions, there will be differences in the amount of gas passing through each part of the wafer surface, making it difficult to form uniform diffusion during impurity diffusion processing or a uniform oxide film during oxidation processing. is difficult.

For this reason, it is necessary to select and process a location in the furnace core tube where the gas flow is uniform.

However, since a normal wafer holder does not have the ability to rotate around the axis of the furnace core tube, there is little freedom in arranging the wafer, and it can be placed in any location, in any direction, or in any direction.
It is extremely difficult to process the slope.

(Purpose of the invention) The purpose of this invention is to improve the above-mentioned drawbacks, and to set the wafer at an arbitrary angle around the axis of the furnace core tube, the wafer can be rotated at an arbitrary inclination. The present invention provides a wafer holder that can be installed in a furnace core tube in the same state as the wafer holder.

(Structure of the invention) The wafer holder according to the invention consists of a susceptor part that holds the wafer and a cylindrical part that rotates the susceptor part at an arbitrary angle and installs it in the furnace core tube.

(Example) FIG. 1 shows an example. Four pairs of protrusions 3 are provided along the depth inside the cylindrical part 2 made of a quartz tube.
A wafer stand 4 is placed between the upper and lower sides (two quartz rods are provided in parallel), and a wafer is inserted between the notches 5 of the upper and lower wafer stands.

In this embodiment, the susceptor part is fixedly integrated with the cylindrical part, so when inserting or removing the wafer holder of the present invention into or out of the furnace core tube, it is preferable to operate the cylindrical part, which has a large mechanical strength. .

The cylindrical part 2 is connected to the furnace core tube (the first
It consists of a quartz tube with a radius R that circumscribes the inner diameter of 6) in the figure, and the angle at which the semiconductor wafer is installed in this quartz tube is adjusted around the axis of the furnace core tube. In addition, a through hole 7 is provided which can also be used for putting in and taking out.

The hook-shaped tip of a rod (not shown) for moving in and out of the wafer holder is inserted into this through hole and operated, utilizing the frictional resistance that moves between the inner wall of the furnace core tube and the outer wall of the quartz tube 2. The wafer can be processed by fixing it at a predetermined position at a desired tilt.

(Advantages of the Invention) According to the present invention, it is possible to place the wafer at any angle to the center of the gas flow in the furnace core tube, which makes it easy to process the semiconductor wafer uniformly.

Using the wafer holder of this invention, a silicon wafer with a diameter of 100 mm was heat-treated at 1140°C for 2 hours in a wet oxygen atmosphere, and the oxide film thickness formed on the wafer surface was determined for 10 rotation angles of the cylindrical part. When the distribution was measured, the variation in film thickness within the wafer was ±2% at maximum and ±0.3% at minimum. In other words, by rotating the cylindrical part and setting the wafer at the optimal position (the position with the least variation), the uniformity of the oxide film thickness within the wafer is significantly improved compared to the conventional method, which improves the yield of semiconductor devices. It has been demonstrated that this invention makes a significant contribution, and the economic significance of this invention is extremely high.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing an embodiment of the present invention. 1: Semiconductor wafer, 2: A quartz tube forming the main part of the cylindrical part, 3: A quartz rod for fixing the susceptor part provided on the inner wall of the cylindrical part, 4: A wafer stand forming the main part of the susceptor part. 5: Notches for inserting wafers provided in wafer stand 4, 6: Furnace core tube, 7: Through hole.

Claims (1)

[Scope of utility model registration request] A pair of susceptor parts: a cylindrical part that slidably circumscribes the inner diameter of the furnace core tube and has one or more through holes and protrusions for holding the susceptor on the tube wall; and a pair of susceptor parts that have notches for fixing the wafer. A wafer holder comprising at least four pairs of projections along the depth of the cylindrical portion.