JP2023020503A5

JP2023020503A5 -

Info

Publication number: JP2023020503A5
Application number: JP2021125900A
Authority: JP
Filing date: 2021-07-30
Publication date: 2024-03-27

Description

前記課題を解決するためになされた、本発明に係るシリコン単結晶の製造方法は、チャンバ内においてヒータの加熱によりルツボ内にシリコン溶融液を形成し、チョクラルスキー法によりシリコン単結晶を育成するシリコン単結晶の製造方法であって、前記ルツボ内にシリコン溶融液を形成する際、該シリコン溶融液に主ドーパントを添加するステップと、前記主ドーパントが添加されたシリコン溶融液からシリコン単結晶を育成するステップと、前記シリコン単結晶を育成するステップの前に、前記ルツボ内のシリコン溶融液に対し水平磁場を印加するステップと、を備え、前記シリコン単結晶を育成するステップにおいて、連続的または断続的に、前記主ドーパントとは反対の導電型を有する副ドーパントを前記シリコン溶融液に添加するステップを有し、前記副ドーパントを前記シリコン溶融液に添加するステップにおいて、１または複数のチップ状ドーパントを前記チャンバ内に搬送するステップと、１または複数のチップ状ドーパントを漏斗状治具に落下させ、前記漏斗状治具に設けられた細管を介して前記チップ状ドーパントを前記シリコン溶融液に投入するステップと、を有し、前記シリコン単結晶を育成するステップの際、前記主ドーパントとは反対の導電型を有する副ドーパントを前記シリコン溶融液に添加するステップにおいて、水平磁場におけるドーパント落下位置を、磁場印可方向を０°と定義した場合、４５°～１３５°、及び２２５°～３１５°の領域とすることに特徴を有する。 A method for manufacturing a silicon single crystal according to the present invention, which was made to solve the above problems, forms a silicon melt in a crucible by heating with a heater in a chamber, and grows a silicon single crystal by the Czochralski method. A method for producing a silicon single crystal, the method comprising: adding a main dopant to the silicon melt when forming a silicon melt in the crucible; and producing a silicon single crystal from the silicon melt to which the main dopant has been added. and a step of applying a horizontal magnetic field to the silicon melt in the crucible before the step of growing the silicon single crystal, and in the step of growing the silicon single crystal, continuous or intermittently adding a sub-dopant having a conductivity type opposite to that of the main dopant to the silicon melt, the step of adding the sub-dopant to the silicon melt comprising one or more chip-shaped transporting dopants into the chamber ; dropping one or more chip-shaped dopants into a funnel-shaped jig, and introducing the chip-shaped dopants into the silicon melt through a thin tube provided in the funnel-shaped jig; and adding a sub dopant having a conductivity type opposite to that of the main dopant to the silicon melt during the step of growing the silicon single crystal, the dopant falling position in a horizontal magnetic field. is characterized in that, when the magnetic field application direction is defined as 0°, the range is from 45° to 135° and from 225° to 315° .

尚、前記シリコン単結晶を育成するステップにおいて、前記副ドーパントを前記シリコン溶融液に添加するステップの後に、シリコン単結晶が有転位化した場合には、有転位化したシリコン単結晶を再溶融するステップと、主ドーパントのチップ状ドーパントをシリコン溶融液に添加するステップと、前記シリコン溶融液からシリコン単結晶を再育成するステップと、前記シリコン単結晶を再育成するステップにおいて、連続的または断続的に、前記主ドーパントとは反対の導電型を有する副ドーパントを前記シリコン溶融液に添加するステップと、を更に備えることが望ましい。
また、前記ドーパント落下位置は、シリコン単結晶の外表面から径方向に、シリコン単結晶の結晶直径の１／１０の距離以上離れた位置であることが望ましい。 In addition, in the step of growing the silicon single crystal, if the silicon single crystal becomes dislocated after the step of adding the sub-dopant to the silicon melt, the dislocated silicon single crystal is remelted. a step of adding a chip-like dopant as a main dopant to a silicon melt ; a step of regrowing a silicon single crystal from the silicon melt; and a step of regrowing the silicon single crystal, either continuously or intermittently. Preferably, the method further includes the step of adding a sub-dopant having a conductivity type opposite to that of the main dopant to the silicon melt.
Further, it is preferable that the dopant fall position be a position radially away from the outer surface of the silicon single crystal at a distance of 1/10 or more of the crystal diameter of the silicon single crystal.

このような方法によれば、主ドーパントを添加したシリコン溶融液からシリコン単結晶を引き上げて育成する際、連続的または断続的に、主ドーパントとは反対の導電型を有するチップ状の副ドーパントを前記シリコン溶融液に添加することにより、シリコン単結晶の軸方向に沿った抵抗率を規格範囲内に収めることができる。
特に、チップ状ドーパントをシリコン溶融液に添加する際に、チャンバ内に配置された漏斗状治具を介してチップ状ドーパントをピンポイントで液面の正確な位置に落下させるため、融液表面の流れに影響を与えず、ドーパント投入に起因する有転位の発生を抑制することができる。
また、シリコン単結晶の育成中にドーパントを追加する構成として、比較的簡易な構成により実現でき、且つチップ単位で必要な量のドーパントを追加することができるため、正確な抵抗率の制御を可能とすることができる。 According to such a method, when a silicon single crystal is pulled and grown from a silicon melt containing a main dopant, a chip-shaped sub-dopant having a conductivity type opposite to that of the main dopant is continuously or intermittently added. By adding it to the silicon melt, the resistivity along the axial direction of the silicon single crystal can be kept within the standard range.
In particular, when adding chip-shaped dopants to a silicon melt, the chip-shaped dopants are pinpointed and dropped to a precise position on the liquid surface via a funnel-shaped jig placed in the chamber. The generation of dislocations caused by dopant injection can be suppressed without affecting the flow.
In addition, it is possible to achieve a configuration in which dopants are added during the growth of silicon single crystals using a relatively simple configuration, and the required amount of dopant can be added per chip, making it possible to accurately control resistivity. It can be done.

また、前記課題を解決するためになされた、本発明に係る単結晶引上装置は、ヒータにより加熱されるチャンバ内に配置されたルツボ内でシリコン溶融液を形成し、チョクラルスキー法によりシリコン単結晶を引き上げるシリコン単結晶引上装置において、前記ルツボの上方において育成するシリコン単結晶を囲むように配置された遮蔽シールドと、前記ルツボ内のシリコン溶融液に対し水平磁場を印加する水平磁場印加手段と、前記遮蔽シールドに取り付けられ、上方に開口する円錐部と該円錐部の下頂部から下方に伸びる細管とからなり、水平磁場におけるドーパント落下位置が、磁場印可方向を０°と定義した場合、４５°～１３５°、及び２２５°～３１５°の領域となるように配置される漏斗状治具と、１または複数のチップ状ドーパントを前記漏斗状治具における円錐部の開口に投入する押込み棒と、を備え、前記漏斗状治具における円錐部の開口に投入されたチップ状ドーパントは、前記漏斗状治具の細管を通って前記シリコン溶融液に落下することに特徴を有する。 Further, the single crystal pulling apparatus according to the present invention, which was made to solve the above problem, forms a silicon melt in a crucible placed in a chamber heated by a heater, and uses the Czochralski method to form a silicon melt. In a silicon single crystal pulling apparatus for pulling up a single crystal, a shielding shield is arranged to surround the silicon single crystal being grown above the crucible, and a horizontal magnetic field is applied to apply a horizontal magnetic field to the silicon melt in the crucible. means, a conical part attached to the shield and opening upward, and a thin tube extending downward from the lower top of the conical part , and the dopant falling position in a horizontal magnetic field is defined as 0° in the direction of application of the magnetic field. In this case, a funnel-shaped jig is arranged in the range of 45° to 135° and 225° to 315° , and one or more chip-shaped dopants are introduced into the opening of the conical part of the funnel-shaped jig. A push rod is provided, and the chip-shaped dopant introduced into the opening of the conical part of the funnel-shaped jig is characterized in that it falls into the silicon melt through the thin tube of the funnel-shaped jig.

尚、前記押込み棒の先端部は、スプーン状に形成され、前記押込み棒は、軸回りに回転可能に設けられていることが望ましい。 Note that it is preferable that the tip of the push rod be formed into a spoon shape, and that the push rod be rotatably provided around an axis.

Claims

A method for producing a silicon single crystal, comprising forming a silicon melt in a crucible by heating with a heater in a chamber, and growing a silicon single crystal by a Czochralski method, the method comprising:
When forming a silicon melt in the crucible, adding a main dopant to the silicon melt;
growing a silicon single crystal from the silicon melt to which the main dopant is added;
Before the step of growing the silicon single crystal, applying a horizontal magnetic field to the silicon melt in the crucible,
In the step of growing the silicon single crystal, the step of continuously or intermittently adding a sub dopant having a conductivity type opposite to the main dopant to the silicon melt,
The step of adding the sub-dopant to the silicon melt includes the steps of : transporting one or more chip-shaped dopants into the chamber ; dropping the one or more chip-shaped dopants into a funnel-shaped jig; Injecting the chip-shaped dopant into the silicon melt via a thin tube provided in a jig,
In the step of growing the silicon single crystal, in the step of adding a sub dopant having a conductivity type opposite to that of the main dopant to the silicon melt, the dopant falling position in a horizontal magnetic field is set to 0° in the direction of magnetic field application. A method for producing a silicon single crystal, characterized in that, when defined, the range is from 45° to 135° and from 225° to 315° .

In the step of growing the silicon single crystal, if the silicon single crystal becomes dislocated after the step of adding the sub-dopant to the silicon melt,
a step of remelting the dislocated silicon single crystal;
adding a chip-shaped dopant as a main dopant to the silicon melt ;
Re-growing a silicon single crystal from the silicon melt;
In the step of regrowing the silicon single crystal, continuously or intermittently adding a sub-dopant having a conductivity type opposite to that of the main dopant to the silicon melt;
The method for manufacturing a silicon single crystal according to claim 1, further comprising:

The dopant falling position is a position radially away from the outer surface of the silicon single crystal at a distance of at least 1/10 of the crystal diameter of the silicon single crystal. A method for producing silicon single crystals.

In a silicon single crystal pulling device that forms a silicon melt in a crucible placed in a chamber heated by a heater and pulls a silicon single crystal using the Czochralski method,
a shielding shield arranged to surround a silicon single crystal grown above the crucible;
horizontal magnetic field applying means for applying a horizontal magnetic field to the silicon melt in the crucible;
It is attached to the shield and consists of a conical part opening upward and a thin tube extending downward from the lower top of the conical part, and the dopant falling position in a horizontal magnetic field is 45° when the magnetic field application direction is defined as 0°. A funnel-shaped jig arranged in an area of 135° to 135° and 225° to 315° ;
a push rod for introducing one or more chip-shaped dopants into the opening of the conical part of the funnel-shaped jig,
A single crystal pulling apparatus characterized in that the chip-shaped dopant introduced into the opening of the conical part of the funnel-shaped jig passes through a thin tube of the funnel-shaped jig and falls into the silicon melt.

The tip of the push rod is shaped like a spoon,
5. The single crystal pulling apparatus according to claim 4, wherein the push rod is rotatably provided around an axis.