JP3337316B2 - Wafer boat for vertical heat treatment furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer boat for a vertical heat treatment furnace, and more particularly, to an improvement in a column structure thereof.

[0002]

2. Description of the Related Art A wafer boat for a vertical heat treatment furnace is installed upright in the heat treatment furnace, and is composed of four vertical columns, a top plate and a bottom plate. A large number of wafer holding grooves are formed in each of the columns, and the wafer ends are inserted and locked in the wafer holding grooves, so that a large number of wafers are supported horizontally in the furnace. Then, the two columns are arranged at a distance of about 180 degrees in the circumferential direction, and the wafer is mounted and taken out from between these columns.

[0003]

However, in such a conventional wafer boat, the load due to the wafer's own weight is large at the outer peripheral portion of the wafer that is in contact with the groove of the column, and slip due to thermal stress starts from the contact point. Had occurred.

Accordingly, an object of the present invention is to provide a wafer boat for a vertical heat treatment furnace which prevents occurrence of wafer slip. Also, wafer loading,
It is an object of the present invention to provide a wafer boat that can be easily taken out.

[0005]

According to the first aspect of the present invention, there are provided three pillars extending in a vertical direction in a state of being inserted into a vertical heat treatment furnace, and a supporting member for supporting these pillars. A groove for engaging the end of the wafer with each column, a plurality of vertical heat treatment furnace wafer boats formed along the length of the column, at least one of the three columns the one is a vertical heat treatment furnace for wafers boat movably configured for circumferentially.

According to a second aspect of the present invention, the three columns are arranged at equal angular intervals on the same circumference.
4. A wafer boat for a vertical heat treatment furnace according to item 1.

[0007]

In the wafer boat for a vertical heat treatment furnace according to the present invention, the contact between the wafer end portion and the groove wall of the column is made at three places. As a result, the number of contact points between the support and the groove wall is small, and it is possible to suppress the occurrence of slip due to thermal stress starting from this contact portion. At the same time, one pillar
Since it can move in the circumferential direction, it is possible to freely insert and remove the wafer. Further, when supporting the wafer, the three columns are arranged at equal intervals, and can support the load of the wafer on average. Therefore, the occurrence of slip is also suppressed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention.

[0009] As shown in these figures, the outer shape of the wafer boat 11 is generally formed in a substantially cylindrical shape. The wafer boat 11 is made of various materials, and is made of, for example, quartz, silicon (polycrystal, single crystal), SiC, one coated with SiC, or the like. The wafer boat 11 includes a circular lower support plate (bottom plate) 12 held horizontally in the heat treatment furnace,
2 and three circular columns 13 and a circular upper connecting plate (top plate) 14 connecting the upper ends of the columns 13 to each other.
And

[0010] These three pillars 13 are positioned on the same circumference with respect to the bottom plate 12 and the top plate 14 in the circumferential direction.
They are arranged at equal distances apart. In the wafer boat 11, one of the columns 13 is configured to be movable by a predetermined angle along the circumferential direction. That is, curved arc grooves 15 extending in the circumferential direction are formed in the connection and support portions between the bottom plate 12 and the top plate 14 and the one support 13, respectively. The column 13 is configured to be movable in the circumferential direction along the arc groove 15, so that the space between the columns 13, 13 can be greatly increased when the wafer is charged. After the wafer is charged, the columns 13 are arranged at the original position, that is, the three columns are arranged at equal intervals.

[0011] These pillars 13 are formed with a large number of wafer holding grooves 16 along the longitudinal direction. These grooves 16 have a U-shaped cross section or a triangular cross section, and the back surface of the end portion of the wafer comes into contact with the bottom wall. The wafer is held horizontally by the support columns 13 by locking the wafer ends in these grooves 16.

As a result, the support of the wafer during the heat treatment is:
A wide range of surface contact or line contact is obtained, the stress of the wafer's own weight can be uniformly dispersed, and no slip occurs. In the above embodiment, a wafer boat having three columns has been described. However, the wafer boat according to the present invention can be applied to a boat having four or more columns. In the case of four or more struts, it is preferable that one or two struts can be moved to form a wafer loading / unloading part. Further, these plural columns are configured to support the wafer at equal intervals, as in the above embodiment.

[0013]

According to the present invention, it is possible to prevent the occurrence of slip due to the weight of the wafer during the heat treatment. In addition, wafers can be easily taken in and out of the boat.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a wafer boat according to one embodiment of the present invention.

FIG. 2 is a bottom view showing a bottom plate of the wafer boat according to one embodiment of the present invention.

[Explanation of symbols]

 11 Wafer Boat 12 Bottom Plate 13 Support 14 Top Plate 15 Circular Groove 16 Groove

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-295227 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/22

Claims (2)

(57) [Claims] 1. A vertical type heat treatment furnace comprising three columns extending in a vertical direction in a state of being loaded into a vertical heat treatment furnace, and a support member for supporting these columns. A vertically aligned heat treatment furnace wafer boat in which a plurality of grooves are formed along the length direction of the columns, wherein at least one of the three columns is circumferentially opposed. Vertically movable wafer boat for heat treatment furnace. 2. A wafer boat for a vertical heat treatment furnace according to claim 1, wherein said three columns are arranged at equal angular intervals on the same circumference.