JP2017154901A5

JP2017154901A5 -

Info

Publication number: JP2017154901A5
Application number: JP2016036629A
Authority: JP
Filing date: 2016-02-29
Publication date: 2018-05-10
Anticipated expiration: 2036-02-29

Description

本発明において、前記カメラの撮影画像は、前記単結晶の引き上げ軸方向と直交する方向を行方向とし、前記引き上げ軸方向と平行な方向を列方向とする二次元画像であり、前記直径計測処理は、前記フュージョンリングと交差し且つ前記行方向に延びる少なくとも一本の測定ラインを前記直径計測領域に設定し、前記フュージョンリングと前記測定ラインとの交点の位置から前記単結晶の直径を求めることが好ましい。この方法によれば、撮影画像中のフュージョンリングから単結晶の直径を正確かつ容易に求めることができる。
In the present invention, the captured image of the camera is a two-dimensional image in which a direction orthogonal to the pulling axis direction of the single crystal is a row direction and a direction parallel to the pulling axis direction is a column direction, and the diameter measurement process Set at least one measurement line that intersects with the fusion ring and extends in the row direction in the diameter measurement region, and obtains the diameter of the single crystal from the position of the intersection of the fusion ring and the measurement line. Is preferred. According to this method, the diameter of the single crystal can be accurately and easily obtained from the fusion ring in the photographed image.

次に、測定ラインＬ_１とフュージョンリング４との２つの交点Ｄ_１、Ｄ_１'を検出する。フュージョンリング４と第１の測定ラインＬ_１との一方の交点Ｄ_１の座標を（ｘ_１，ｙ_１）とし、他方の交点Ｄ_１'の座標を（ｘ _１ '，ｙ _１）とする。フュージョンリング４と測定ラインＬ_１との交点Ｄ_１、Ｄ_１'の概略位置は、測定ラインＬ_１上の輝度ピークの位置である。フュージョンリング４と測定ラインＬ_１との交点Ｄ_１、Ｄ_１'の詳細位置については後述する。
Next, two intersections D ₁ and D ₁ ′ between the measurement line L ₁ and the fusion ring 4 are detected. The coordinates of _one intersection D ₁ of the fusion ring 4 and the first measurement line L ₁ are (x ₁ , y ₁ ), and the coordinates of the other intersection D ₁ ′ are (x ₁ ′, y ₁ ) . The approximate positions of the intersections D ₁ and D ₁ ′ between the fusion ring 4 and the measurement line L ₁ are the positions of the luminance peaks on the measurement line L ₁ . Detailed positions of the intersection points D ₁ and D ₁ ′ between the fusion ring 4 and the measurement line L ₁ will be described later.

図８に示すように、この設定方法では、最高輝度の列方向の分布１０１から閾値Ｈ以下の最高輝度を持つ行に測定ラインＬ_１を設定する。具体的には、類似輝度がある範囲以上存在している画素の輝度を固液界面部の輝度Ｐｉとし、固液界面部の輝度Ｐｉを同一画素列内の最高輝度Ｐｍと比較し、固液界面部の輝度Ｐｉと最高輝度Ｐｍと輝度差が閾値Ｈ以下となるＸ軸方向の画素列を直径計測対象領域とする。図７のように最高輝度の最小値Ｐ_１を持つ行に測定ラインを設定する場合にはその一行にしか測定ラインを設定することができないので、画像処理上の制約が大きく、また複数の測定ラインを設定することもできない。しかし閾値Ｈ以下であればどこでもよいとする場合には、測定ラインの設定範囲に多少の幅を持たせることができ、測定ラインの設定位置の自由度を高めることができる。また撮影画像中に２本以上の測定ラインを設定することも可能である。

As shown in FIG. 8, in this setting method, setting the measurement line L ₁ from the column direction of the distributions 101 brightest in the row with the highest luminance than the threshold H. Specifically, the luminance of a pixel having similar luminance above a certain range is set as the luminance Pi of the solid-liquid interface, and the luminance Pi of the solid-liquid interface is compared with the maximum luminance Pm in the same pixel column. A pixel column in the X-axis direction in which the luminance difference between the luminance Pi of the interface portion, the maximum luminance Pm, and the luminance is equal to or less than the threshold value H is set as a diameter measurement target region. Because can only set the measurement line on the line when configuring the measurement line to the line having the minimum value P ₁ of the highest luminance as shown in FIG. 7, the image processing constraints is large, a plurality of measurement The line cannot be set. However, if it can be anywhere as long as it is less than or equal to the threshold value H, the setting range of the measurement line can be given a little width, and the degree of freedom of the setting position of the measurement line can be increased. It is also possible to set two or more measurement lines in the captured image.

Claims

During the step of pulling up the single crystal by the Czochralski method, an image of the boundary portion between the single crystal and the melt surface is taken with a camera, and at least the maximum luminance distribution in the circumferential direction of the fusion ring that appears at the boundary portion A single value is set as a threshold value, and a region where the maximum luminance is less than or equal to the threshold value in the maximum luminance distribution is designated as a diameter measurement region, and the diameter measurement processing of the single crystal being pulled is performed. Crystal production method.

The photographed image of the camera is a two-dimensional image having a direction perpendicular to the pulling axis direction of the single crystal as a row direction and a direction parallel to the pulling axis direction as a column direction,
The diameter measurement process
Setting at least one measurement line intersecting the fusion ring and extending in the row direction in the diameter measurement region;
The method for producing a single crystal according to claim 1, wherein a diameter of the single crystal is obtained from a position of an intersection between the fusion ring and the measurement line.

The manufacturing method of the single crystal of Claim 2 which sets the said measurement line to the line | wire with the highest brightness | luminance below the said threshold value among the highest brightness | luminances of each line | wire of the said picked-up image.

The manufacturing method of the single crystal of Claim 2 which sets the said measurement line to the line with the minimum value of the said highest brightness among the highest brightness | luminances of each line of the said picked-up image.

The photographed image is divided in the column direction, and in each of the plurality of divided regions, a row having a minimum value of the highest luminance is selected from among the highest luminances of the rows in the divided region, and the plurality of divided regions are selected. The method for producing a single crystal according to claim 4, wherein the measurement line is set in at least one of a plurality of rows selected from each.

The photographed image is divided in the column direction, and in each of the plurality of divided regions, a divided region in which the average value is minimum is selected from the average values of the highest luminance of each row in the divided region, and the selected region is selected. The method for producing a single crystal according to claim 4, wherein the measurement line is set in the divided area.

7. The method for producing a single crystal according to claim 5, wherein the photographed image is divided by setting a dividing line in a row having a maximum value of the maximum luminance of each row.

A crucible supporting the melt,
A heater for heating the melt;
A pulling shaft for pulling up the single crystal from the melt;
A crucible lifting mechanism for controlling the vertical position of the crucible;
A camera that captures an image of the boundary between the single crystal and the melt;
An image processing unit for processing an image captured by the camera;
A control unit for controlling the heater, the lifting shaft and the crucible lifting mechanism;
The image processing unit
A value smaller than at least the maximum value of the maximum luminance distribution in the circumferential direction of the fusion ring appearing in the boundary portion is set as a threshold, and a region where the maximum luminance is equal to or less than the threshold in the maximum luminance distribution is designated as a diameter measurement region, An apparatus for producing a single crystal, which performs a diameter measuring process of the pulled single crystal.