JP2021022676A

JP2021022676A - Ion implantation method and ion implanter

Info

Publication number: JP2021022676A
Application number: JP2019139075A
Authority: JP
Inventors: 喜太郎山崎; Kitaro Yamazaki; 秀和横尾; Hidekazu Yokoo; 現示酒田; Genji Sakata
Original assignee: Ulvac Inc
Current assignee: Ulvac Inc
Priority date: 2019-07-29
Filing date: 2019-07-29
Publication date: 2021-02-18
Anticipated expiration: 2039-07-29
Also published as: JP7256712B2

Abstract

To provide an ion implantation method capable of achieving high mass-productiveness, without compromising the functionality that the temperature of a substrate is not raised above a specific temperature.SOLUTION: An ion implantation method includes a first step of placing multiple substrates Sw, respectively, on stages 2a, 2b separately placed in a vacuum chamber 1, irradiating the principal surface of the substrate installed in the stage 2a with an ion beam controlled to a prescribed impregnation energy by accelerating by means of an accelerator 41a, and implanting ions in a unit processing time set shorter than a total processing time capable of obtaining a prescribed dosage, a second step of implanting ions in the unit processing time by changing the emission direction of the ion beam, and irradiating the principal surface of the substrate installed in the stage 2b with the ion beam, and a third step of moving other substrates to the irradiation position in place of the substrate implanted with ions in the unit processing time by the stage, between the first and second steps, and the first step, the second step and the third step are repeated multiple times until the unit processing time reaches the total processing time.SELECTED DRAWING: Figure 1

Description

本発明は、イオン注入方法及びイオン注入装置に関し、より詳しくは、ＬＴ（ＬｉＴａＯ_３）基板やＬＮ（ＬｉＮｂＯ_３）基板といった半導体単結晶ウエハの主面に、水素イオンや、ヘリウムイオン等の希ガスのイオンをその表面から数ミクロンの深さに高濃度でイオン注入するためのものに関する。 The present invention relates to an ion implantation method and an ion implantation apparatus. More specifically, the present invention relates to a rare gas such as hydrogen ion or helium ion on a main surface of a semiconductor single crystal wafer such as an LT (LiTaO ₃ ) substrate or an LN (LiNbO ₃ ) substrate. It relates to a high-concentration ion implantation of ions from the surface to a depth of several microns.

従来、基板の主面に対して高い注入エネルギを持つイオンビームを照射して、所定のドーズ量のイオンをその表面から数ミクロンの深さに高濃度でイオン注入する際に、基板を所定温度以下に保持できるようにしたイオン注入装置は例えば特許文献１で知られている。このものは、加速器により加速することで所定の注入エネルギに制御されたイオンビームを偏向するビーム偏向器と、このビーム偏向器を経たイオンビームを用いてイオン注入する、基板が配置される複数のイオン注入室（イオン打ち込み室）とを有する。各イオン注入室には、基板が装着される水冷回転円盤と、この水冷回転円盤を回転させると共に半径方向に往復運動させる水冷回転円盤駆動機構とが設けられている。 Conventionally, when an ion beam having a high implantation energy is irradiated to the main surface of a substrate to implant a predetermined dose of ions from the surface at a high concentration to a depth of several microns, the substrate is implanted at a predetermined temperature. An ion implanter that can be held below is known, for example, in Patent Document 1. This is a beam deflector that deflects an ion beam controlled to a predetermined injection energy by accelerating with an accelerator, and a plurality of substrates on which ions are implanted using the ion beam that has passed through the beam deflector. It has an ion implantation chamber (ion implantation chamber). Each ion implantation chamber is provided with a water-cooled rotary disk on which a substrate is mounted and a water-cooled rotary disk drive mechanism that rotates the water-cooled rotary disk and reciprocates in the radial direction.

上記従来例のイオン注入装置では、イオン注入室を複数個設けて、加速器により加速されたイオンビームを各イオン注入室に夫々振り分けてその注入エネルギをイオン注入室毎に分散させると共に、イオン注入時に基板を水冷回転円盤からの伝熱で冷却することで、各イオン注入室に夫々設置された基板を所定温度以上に昇温させることなく、高い注入エネルギでイオン注入することができるようになっている。 In the ion implantation apparatus of the above-mentioned conventional example, a plurality of ion implantation chambers are provided, the ion beam accelerated by the accelerator is distributed to each ion implantation chamber, and the implantation energy is dispersed in each ion implantation chamber, and at the time of ion implantation. By cooling the substrate by heat transfer from a water-cooled rotary disk, it is possible to implant ions with high implantation energy without raising the temperature of the substrate installed in each ion implantation chamber above a predetermined temperature. There is.

ここで、基板が上記半導体単結晶ウエハである場合、例えばイオン注入時の基板の昇温により分極することが一般に知られている。このため、上記従来例のように基板を水冷回転円盤に装着させていると、その表面に基板が静電吸着してしまうという問題があり、これでは、イオン注入中に基板の破損を招来する虞があるばかりか、処理済みの基板のイオン注入室からの円滑な搬出が阻害されてしまう。ところで、スマートカットのために、半導体単結晶ウエハに水素イオンやヘリウムイオンを数ミクロンの深さに高濃度に導入する場合、高い注入エネルギに制御したイオンビームを照射するといっても、所定のドーズ量を得るには、数時間に及ぶ処理時間が必要になる。このため、基板の温度を所定温度以上に上昇させないという機能を損なうことなく、高い量産性を達成できるようにする必要もある。 Here, when the substrate is the semiconductor single crystal wafer, it is generally known that the substrate is polarized by raising the temperature of the substrate at the time of ion implantation, for example. For this reason, when the substrate is mounted on the water-cooled rotary disk as in the above-mentioned conventional example, there is a problem that the substrate is electrostatically adsorbed on the surface thereof, which causes damage to the substrate during ion implantation. Not only is there a risk, but the smooth removal of the treated substrate from the ion implantation chamber is hindered. By the way, when hydrogen ions or helium ions are introduced into a semiconductor single crystal wafer at a high concentration to a depth of several microns for smart cutting, even if it is said that an ion beam controlled to a high injection energy is irradiated, a predetermined dose is applied. It takes several hours of processing time to obtain the quantity. Therefore, it is also necessary to achieve high mass productivity without impairing the function of not raising the temperature of the substrate above a predetermined temperature.

特開平６−１９６１１９号公報Japanese Unexamined Patent Publication No. 6-196119

本発明は、以上の点に鑑みなされたものであり、基板の温度を所定温度以上に上昇させないという機能を損なうことなく、高い量産性を達成できるイオン注入方法及びイオン注入装置を提供することを課題とするものである。 The present invention has been made in view of the above points, and provides an ion implantation method and an ion implantation apparatus capable of achieving high mass productivity without impairing the function of not raising the temperature of the substrate above a predetermined temperature. This is an issue.

上記課題を解決するために、本発明のイオン注入方法は、真空チャンバ内で互いに離隔配置された少なくとも２個のステージに、複数枚の基板を夫々配置し、基板面内で互いに直交する二方向をＸ軸方向及びＹ軸方向とし、いずれか一つのステージに設置された静止状態のいずれか一つの基板の主面に対し、加速器により加速することで所定の注入エネルギに制御したイオンビームを照射し、所定のドーズ量が得られる基板へのイオンビームの照射時間を総処理時間とし、総処理時間より短く設定した単位処理時間でＸ軸方向及びＹ軸方向に走査させてイオン注入する第１工程と、イオンビームの出射方向を変えて、いずれか他のステージに設置された静止状態のいずれか一つの基板の主面に対してイオンビームを照射し、単位処理時間でＸ軸方向及びＹ軸方向に走査させてイオン注入する第２工程と、基板に対してイオンビームが照射されるステージの位置を照射位置とし、第１工程と第２工程との間に、ステージにより単位処理時間でイオン注入された基板に代えて他の基板を照射位置に移動させる第３工程とを含み、第１工程、第２工程及び第３工程を単位処理時間が総処理時間に達するまで複数回繰り返すことを特徴とする。 In order to solve the above problems, the ion implantation method of the present invention arranges a plurality of substrates on at least two stages separated from each other in a vacuum chamber, and arranges a plurality of substrates in each of the two directions orthogonal to each other in the substrate plane. Is the X-axis direction and the Y-axis direction, and the main surface of any one of the stationary substrates installed on any one stage is irradiated with an ion beam controlled to a predetermined implantation energy by accelerating with an accelerator. Then, the irradiation time of the ion beam on the substrate from which a predetermined dose amount can be obtained is defined as the total processing time, and the unit processing time set shorter than the total processing time is used to scan in the X-axis direction and the Y-axis direction to implant the ions. By changing the process and the emission direction of the ion beam, the ion beam is irradiated to the main surface of any one of the stationary substrates installed on any other stage, and the ion beam is irradiated in the X-axis direction and Y in a unit processing time. The second step of scanning in the axial direction and implanting ions and the position of the stage where the ion beam is irradiated to the substrate are set as the irradiation position, and the unit processing time is set by the stage between the first step and the second step. The first step, the second step, and the third step are repeated a plurality of times until the unit processing time reaches the total processing time, including the third step of moving another substrate to the irradiation position instead of the ion-implanted substrate. It is characterized by.

本発明によれば、ステージを２個とした場合を例に説明すると、各ステージに同数の複数枚の基板を夫々セットする。次に、真空チャンバを真空雰囲気とした後、第１ステージの第１の基板の主面に対してイオンビームが照射され、このイオンビームをＸ軸方向及びＹ軸方向に走査させてその全面に亘ってイオン注入される（第１工程）。このとき、イオンビームの照射時間としての単位処理時間は、イオンビーム照射時の基板の温度上昇速度などを考慮して適宜設定される。 According to the present invention, to explain the case where two stages are used as an example, a plurality of substrates of the same number are set in each stage. Next, after creating a vacuum atmosphere in the vacuum chamber, an ion beam is irradiated to the main surface of the first substrate of the first stage, and the ion beam is scanned in the X-axis direction and the Y-axis direction to cover the entire surface thereof. Ions are implanted over (first step). At this time, the unit processing time as the irradiation time of the ion beam is appropriately set in consideration of the temperature rise rate of the substrate at the time of ion beam irradiation.

次に、第１ステージでの第１の基板の主面に対するイオン注入が終了すると、イオンビームの出射方向が変えられ、第２ステージの第１の基板の主面に対して、上記同様、イオンビームが照射されてイオン注入される（第２工程）。第２工程を実施している間において、第１ステージでは、一回目のイオン注入が終了した第１の基板に代えて、次にイオン注入される第２の基板が照射位置に移動される（第３工程）。ここで、第１の基板は、次に（例えば二回目のイオン注入のために）照射位置に移動されるまでは、何らの入熱もないため、第１の基板の主面の温度は次第に下降していく。そして、第２ステージでの第１の基板の主面に対するイオン注入が終了すると、イオンビームの出射方向が変えられ、照射位置に待機している第１ステージの第２の基板の主面に対して、上記同様、イオンビームが照射されてイオン注入される。この間、第２ステージでは、上記同様、一回目のイオン注入が終了した第１の基板に代えて、次にイオン注入される第２の基板が照射位置に移動される。このような操作が、第１及び第２の両ステージの各基板に対してイオンビームの照射時間が総処理時間に達するまでが繰り返され、各基板に対して所定のドーズ量でイオン注入される。 Next, when the ion implantation into the main surface of the first substrate in the first stage is completed, the emission direction of the ion beam is changed, and the ions are applied to the main surface of the first substrate in the second stage in the same manner as described above. The beam is irradiated and ions are implanted (second step). During the second step, in the first stage, the second substrate to be ion-implanted next is moved to the irradiation position in place of the first substrate to which the first ion implantation is completed ( Third step). Here, the temperature of the main surface of the first substrate gradually increases because there is no heat input until the first substrate is moved to the irradiation position next time (for example, for the second ion implantation). It goes down. Then, when the ion implantation into the main surface of the first substrate in the second stage is completed, the emission direction of the ion beam is changed, and the main surface of the second substrate in the first stage is waiting at the irradiation position. Then, as described above, the ion beam is irradiated and the ions are implanted. During this time, in the second stage, similarly to the above, the second substrate to be ion-implanted next is moved to the irradiation position in place of the first substrate to which the first ion implantation is completed. Such an operation is repeated until the irradiation time of the ion beam reaches the total processing time for each substrate of both the first and second stages, and ions are implanted into each substrate with a predetermined dose amount. ..

このように本発明では、一枚の基板に対して、複数回に分けてイオンビームを照射してイオン注入すると共に、各基板の一回のイオン注入後には照射位置から一旦移動させることで、次に照射位置に移動されるまでに基板温度を下げることができ、その間には、他のステージに配置されている基板に対してイオン注入が順次行われる。その結果、基板の温度を所定温度以上に上昇させることなく、高い量産性で複数枚の基板に対してイオン注入することが可能になる。 As described above, in the present invention, one substrate is irradiated with an ion beam in a plurality of times to implant ions, and after one ion implantation of each substrate, the substrate is once moved from the irradiation position. The substrate temperature can be lowered by the time it is moved to the irradiation position, and during that time, ion implantation is sequentially performed on the substrates arranged on other stages. As a result, it is possible to implant ions into a plurality of substrates with high mass productivity without raising the temperature of the substrate to a predetermined temperature or higher.

本発明においては、前記第１工程にてイオン注入された基板が次に照射位置に移動されるまでの間に当該基板を冷却する冷却工程を含むことが好ましい。これによれば、基板に対して所定のドーズ量でイオン注入するまでの間、基板の温度を所定温度以下に確実に保持することができ、有利である。 In the present invention, it is preferable to include a cooling step of cooling the substrate ion-implanted in the first step until the substrate is next moved to the irradiation position. According to this, the temperature of the substrate can be surely maintained below the predetermined temperature until the ions are implanted into the substrate in a predetermined dose amount, which is advantageous.

また、本発明においては、前記第１工程及び第２工程にて前記ステージに立設した支持体により前記基板を支持することが好ましい。これによれば、基板がＬＴ基板やＬＮ基板といった半導体単結晶ウエハである場合に、イオン注入により分極してステージ表面に静電吸着するといった不具合の発生を防止できる。その結果、イオン注入時における基板の破損を防止でき、しかも、処理済みの基板の円滑な搬出が阻害されることはない。 Further, in the present invention, it is preferable to support the substrate by a support erected on the stage in the first step and the second step. According to this, when the substrate is a semiconductor single crystal wafer such as an LT substrate or an LN substrate, it is possible to prevent the occurrence of problems such as polarization due to ion implantation and electrostatic adsorption on the stage surface. As a result, the substrate can be prevented from being damaged during ion implantation, and the smooth delivery of the treated substrate is not hindered.

更に、上記課題を解決するために、上記イオン注入方法の実施を可能とする本発明のイオン注入装置は、ステージが、周方向に間隔を存して複数枚の基板を支持する回転自在な回転板を備え、回転板の一方の面に、基板の裏面に当接可能な第１支持体と基板の外側面に当接可能な第２支持体とが夫々立設され、回転板の回転により、第１支持体及び第２支持体で夫々支持された基板が順次照射位置に移動されるようにしたことを特徴とする。この場合、前記回転板に対峙して設けられ、照射位置以外の位置にある前記基板を放射により冷却する冷却手段を更に備えることが好ましい。 Further, in order to solve the above-mentioned problems, in the ion implantation apparatus of the present invention which enables the implementation of the above-mentioned ion implantation method, the stages are rotatably rotated to support a plurality of substrates at intervals in the circumferential direction. A plate is provided, and a first support that can abut the back surface of the substrate and a second support that can abut the outer surface of the substrate are erected on one surface of the rotating plate. , The substrate supported by the first support and the second support is sequentially moved to the irradiation position. In this case, it is preferable to further provide a cooling means provided so as to face the rotating plate and cool the substrate at a position other than the irradiation position by radiation.

本発明の実施形態のイオン注入装置を示す模式横断面図。The schematic cross-sectional view which shows the ion implantation apparatus of embodiment of this invention. 本発明の実施形態のイオン注入装置を示す模式縦断面図。The schematic vertical sectional view which shows the ion implantation apparatus of embodiment of this invention. （ａ）及び（ｂ）は、ステージでの基板の支持を説明する平面図及び側面図。(A) and (b) are plan views and side views for explaining the support of the substrate on the stage.

以下、図面を参照して、基板をΦ１２インチのＬＮ基板（以下、単に「基板Ｓｗ」という）とし、２個のステージを用いて各基板の主面に、水素イオンや、ヘリウムイオン等の希ガスのイオンをその表面から数ミクロンの深さに高濃度でイオン注入する場合を例に本発明のイオン注入方法及びイオン注入装置の実施形態を説明する。以下において、水平面内で互いに直交する二方向をＸ軸方向及びＹ軸方向、Ｘ軸方向及びＹ軸方向に直交する鉛直方向をＺ軸方向とする。 Hereinafter, referring to the drawings, the substrate is a Φ12 inch LN substrate (hereinafter, simply referred to as “substrate Sw”), and two stages are used to form rare hydrogen ions, helium ions, etc. on the main surface of each substrate. An embodiment of the ion implantation method and the ion implantation apparatus of the present invention will be described by taking as an example a case where gas ions are implanted from the surface to a depth of several microns at a high concentration. In the following, the two directions orthogonal to each other in the horizontal plane are defined as the X-axis direction and the Y-axis direction, and the vertical direction orthogonal to the X-axis direction and the Y-axis direction is defined as the Z-axis direction.

図１及び図２を参照して、本実施形態のイオン注入装置ＩＭは、真空チャンバ１を備える。真空チャンバ１には、特に図示して説明しないが、真空ポンプからの排気管が接続され、真空チャンバ１内を所定圧力に真空排気できるようになっている。真空チャンバ１にはまた、図１に示すように、Ｘ軸方向の中心線に対して左右対称となるように、複数枚の基板Ｓｗを夫々支持する第１ステージ２ａと第２ステージ２ｂが設けられ、これら両ステージ２ａ，２ｂが設けられる真空チャンバ１内の領域がイオン注入室１ａとなる。第１ステージ２ａ及び第２ステージ２ｂは、同一の構成を有し、真空チャンバ１の底面に間隔を存して立設した２本の支柱２１を備える。支柱２１間には回転軸２２が軸支され、回転軸２２に支持板２３が取り付けられている。そして、支持板２３が、基板Ｓｗの主面がＺ軸方向上方を向く水平姿勢と基板Ｓｗの主面が略水平方向を向く起立姿勢との間で図示省略のモータにより回転軸２２を支点として揺動自在となっている。 With reference to FIGS. 1 and 2, the ion implanter IM of the present embodiment includes a vacuum chamber 1. Although not particularly illustrated and described, the vacuum chamber 1 is connected to an exhaust pipe from a vacuum pump so that the inside of the vacuum chamber 1 can be evacuated to a predetermined pressure. As shown in FIG. 1, the vacuum chamber 1 is also provided with a first stage 2a and a second stage 2b that support a plurality of substrates Sw, respectively, so as to be symmetrical with respect to the center line in the X-axis direction. The region in the vacuum chamber 1 where both stages 2a and 2b are provided becomes the ion implantation chamber 1a. The first stage 2a and the second stage 2b have the same configuration, and include two columns 21 erected on the bottom surface of the vacuum chamber 1 at intervals. A rotating shaft 22 is pivotally supported between the columns 21, and a support plate 23 is attached to the rotating shaft 22. Then, the support plate 23 uses the rotating shaft 22 as a fulcrum between a horizontal posture in which the main surface of the substrate Sw faces upward in the Z-axis direction and an upright posture in which the main surface of the substrate Sw faces in the substantially horizontal direction by a motor (not shown). It is swingable.

支持板２３が水平姿勢であるとして、支持板２３の下面にはモータ２４が取り付けられ、その駆動軸２４ａが支持板２３を貫通してその上面まで突出し、この突出した駆動軸２４ａの部分には円盤状の回転板２５が取り付けられている。回転板２５の上面にはまた、回転板２５と同心の仮想円周上に位置させて複数枚（本実施形態では、１２枚）の基板Ｓｗを夫々支持する基板支持部２６が設けられている。基板支持部２６は、同一の構成を有し、回転板２５の上面に立設された複数本（本実施形態では、夫々４本）の第１支持体２６ａと第２支持体２６ｂとを備える。これにより、支持板２３の姿勢変更に伴って回転板２５が水平姿勢と起立姿勢との間で姿勢変更できると共に、水平姿勢と起立姿勢のいずれの姿勢においても、モータ２４により駆動軸２４ａ回りに回転板２５が所定の回転角ごとに間欠的に回転駆動できる。また、図２中に仮想線で示す回転板２５の起立姿勢では、基板支持部２６で夫々支持された複数枚の基板Ｓｗのうちいずれか１枚の基板Ｓｗに対し、後述するようにイオンビームが照射され、このイオンビームが照射される回転板２５の位置（回転角）を照射位置Ｒｐ（図２参照）として、回転板２５の間欠的な回転駆動により順次基板Ｓｗが照射位置Ｒｐに移動されるようになっている。 Assuming that the support plate 23 is in a horizontal posture, a motor 24 is attached to the lower surface of the support plate 23, and a drive shaft 24a thereof penetrates the support plate 23 and protrudes to the upper surface thereof, and the protruding drive shaft 24a is provided. A disk-shaped rotating plate 25 is attached. Further, on the upper surface of the rotating plate 25, a substrate supporting portion 26 is provided which is positioned on a virtual circumference concentric with the rotating plate 25 and supports a plurality of (12 in this embodiment) substrates Sw, respectively. .. The substrate support portion 26 has the same configuration, and includes a plurality of first supports 26a and second supports 26b erected on the upper surface of the rotating plate 25 (four in each of the present embodiments). .. As a result, the rotating plate 25 can change its posture between the horizontal posture and the standing posture according to the posture change of the support plate 23, and the motor 24 rotates around the drive shaft 24a in both the horizontal posture and the standing posture. The rotary plate 25 can be rotationally driven intermittently at each predetermined rotation angle. Further, in the upright posture of the rotating plate 25 shown by the virtual line in FIG. 2, an ion beam is provided for any one of the plurality of substrate Sws supported by the substrate support portion 26, as will be described later. Is irradiated, and the position (rotation angle) of the rotating plate 25 to which the ion beam is irradiated is set as the irradiation position Rp (see FIG. 2), and the substrate Sw is sequentially moved to the irradiation position Rp by the intermittent rotation drive of the rotating plate 25. It is supposed to be done.

第１支持体２６ａ及び第２支持体２６ｂは、図３（ａ）及び図３（ｂ）に示すように、樹脂または金属製のピン状部材で構成され、各第１支持体２６ａは、その先端が基板Ｓｗの裏面に当接して基板Ｓｗを回転板２５上面から所定の高さ位置で支持するように配置されている。この場合、第１支持体２６ａの先端は、基板Ｓｗとの接触面積が可及的に小さくなるように先細りであることが好ましい。他方、第２支持体２６ｂは、回転板２５を起立姿勢にしたときに基板Ｓｗの側面に当接して、回転板２５からの基板Ｓｗの脱落が防止できるように配置されている。第２支持体２６ｂの形状は、基板Ｓｗの側面に当接して回転板２５からの基板Ｓｗの脱落が防止できるものであれば、その形状や配置は上記に限定されるものではない。 As shown in FIGS. 3 (a) and 3 (b), the first support 26a and the second support 26b are made of a resin or metal pin-shaped member, and each of the first supports 26a is a pin-shaped member thereof. The tip is in contact with the back surface of the substrate Sw and is arranged so as to support the substrate Sw at a predetermined height position from the upper surface of the rotating plate 25. In this case, the tip of the first support 26a is preferably tapered so that the contact area with the substrate Sw is as small as possible. On the other hand, the second support 26b is arranged so as to come into contact with the side surface of the substrate Sw when the rotating plate 25 is in the upright posture and prevent the substrate Sw from falling off from the rotating plate 25. The shape and arrangement of the second support 26b is not limited to the above as long as it abuts on the side surface of the substrate Sw and can prevent the substrate Sw from falling off from the rotating plate 25.

真空チャンバ１内の所定位置には、回転板２５に対峙させて冷却手段としての冷却パネル３が設けられ、回転板２５の回転駆動により照射位置Ｒｐ以外の位置に移動された基板Ｓｗを放射により冷却できるようにしている。なお、冷却パネル３としては、極低温冷媒を利用したクライオパネルなど公知のものが利用できるため、これ以上の説明は省略する。また、真空チャンバ１には、ゲートバルブＧｖを介してロードロックチャンバＬｃが連設されている。ロードロックチャンバＬｃには、特に図示して説明しないが、真空ポンプとベントバルブとが配管を介して接続され、その内部を大気雰囲気と真空雰囲気との間で切り換えることができるようになっている。そして、真空チャンバ１内に設けた公知の構造を持つ真空搬送ロボットＲｂにより真空チャンバ１とロードロックチャンバＬｃとの間で基板Ｓｗを搬送できるようにしている。 A cooling panel 3 as a cooling means is provided at a predetermined position in the vacuum chamber 1 so as to face the rotating plate 25, and the substrate Sw moved to a position other than the irradiation position Rp by the rotational drive of the rotating plate 25 is radiated. It is designed to be cooled. As the cooling panel 3, a known one such as a cryopanel using a cryogenic refrigerant can be used, so further description thereof will be omitted. Further, in the vacuum chamber 1, a load lock chamber Lc is continuously provided via a gate valve Gv. Although not particularly illustrated, a vacuum pump and a vent valve are connected to the load lock chamber Lc via a pipe, and the inside thereof can be switched between an air atmosphere and a vacuum atmosphere. .. Then, the substrate Sw can be transferred between the vacuum chamber 1 and the load lock chamber Lc by the vacuum transfer robot Rb having a known structure provided in the vacuum chamber 1.

真空チャンバ１は、イオン注入室１ａからＸ軸方向前方（図１中、左側から右側）に向けて縮径するようにのびる略円錐状のイオン照射室１ｂを備え、イオン照射室１ｂには、イオンビーム照射ユニットＩｕが接続され、起立姿勢の回転板２５に支持された照射位置Ｒｐの基板Ｓｗに対して、イオンビームを照射できるようになっている。イオンビーム照射ユニットＩｕは、高電圧ターミナルが格納される耐圧性の遮蔽箱４１を有する。高電圧ターミナルは、特に図示して説明しないが、イオン源を備え、イオン源が真空配管を介して多種類のイオンの中から、基板Ｓｗにイオン注入しようとするイオン（水素イオンや、ヘリウムイオン等の希ガスのイオン）を取出す質量分析マグネットに接続されている。質量分析マグネットは他の真空配管を介して、高電圧を印加してイオンを加速し、必要な注入エネルギを付与する加速器４１ａに接続されている。加速器４１ａの他端が、遮蔽箱４１の壁面を貫通してＸ−Ｙ走査チャンバ４２に接続されている。 The vacuum chamber 1 includes a substantially conical ion irradiation chamber 1b extending from the ion implantation chamber 1a toward the front in the X-axis direction (from the left side to the right side in FIG. 1), and the ion irradiation chamber 1b is provided with a substantially conical ion irradiation chamber 1b. The ion beam irradiation unit Iu is connected so that the ion beam can be irradiated to the substrate Sw at the irradiation position Rp supported by the rotating plate 25 in the standing posture. The ion beam irradiation unit Iu has a pressure-resistant shielding box 41 in which a high-voltage terminal is stored. Although not particularly illustrated, the high-voltage terminal is provided with an ion source, and the ion source is an ion (hydrogen ion or helium ion) that is to be implanted into the substrate Sw from among various types of ions via a vacuum pipe. It is connected to a mass spectrometric magnet that takes out rare gas ions such as. The mass spectrometric magnet is connected to an accelerator 41a via another vacuum pipe by applying a high voltage to accelerate ions and imparting necessary injection energy. The other end of the accelerator 41a penetrates the wall surface of the shielding box 41 and is connected to the XY scanning chamber 42.

真空ポンプにより所定圧力に真空排気されるＸ−Ｙ走査チャンバ４２には、特に図示して説明しないが、その上流側（図１中、右側）からイオンビームの整形を行う四極子レンズと、高周波を印加してイオンビームをＸ−Ｙ方向にそれぞれ走査する一対の偏向電極（スキャンプレート）とが配設され、Ｘ−Ｙ走査チャンバ４２の下流側がイオン照射室１ｂに連設されている。イオン照射室１ｂには、Ｘ―Ｙ走査チャンバ４２から照射されるイオンビームの出射方向をかえるビーム偏向器４３と、ビーム電流量を測定する２個のファラデーカップ４４ａ，４４ｂとが設けられている。なお、イオンビーム照射ユニットＩｕとしては公知のものが利用できるため、例えば、基板Ｓｗの主面に対するイオンビームの出射方法、注入エネルギの制御方法や、基板Ｓｗの主面に対するイオンビームの走査方法を含め、これ以上の説明は省略する。以下に、上記イオン注入装置ＩＭを用いた基板Ｓｗへのイオン注入方法を具体的に説明する。 The XY scanning chamber 42, which is evacuated to a predetermined pressure by a vacuum pump, is not illustrated and described, but has a quadrupole lens that shapes an ion beam from the upstream side (right side in FIG. 1) and a high frequency. A pair of deflection electrodes (scan plates) for scanning the ion beam in the XY directions by applying the above are arranged, and the downstream side of the XY scanning chamber 42 is continuously provided in the ion irradiation chamber 1b. The ion irradiation chamber 1b is provided with a beam deflector 43 that changes the emission direction of the ion beam emitted from the XY scanning chamber 42, and two Faraday cups 44a and 44b that measure the amount of beam current. .. Since a known ion beam irradiation unit Iu can be used, for example, a method of emitting an ion beam to the main surface of the substrate Sw, a method of controlling injection energy, and a method of scanning the ion beam with respect to the main surface of the substrate Sw can be used. Further description including this will be omitted. The method of ion implantation into the substrate Sw using the ion implantation apparatus IM will be specifically described below.

大気雰囲気のロードロックチャンバＬｃに２４枚の基板ＳｗをセットしたカセットＣｔを設置した後、真空ポンプによりロードロックチャンバＬｃを真空排気する。このとき、真空チャンバ１内は、真空ポンプにより真空排気されて所定圧力になっており、また、各ステージ２ａ，２ｂは夫々水平姿勢となっている。ロードロックチャンバＬｃ内が所定圧力まで真空排気されると、ゲートバルブＧｖを開けて真空搬送ロボットＲｂによりカセットＣｔから順次基板Ｓｗを取り出し、水平姿勢の各ステージ２ａ，２ｂにて、回転板２５を適宜回転させながら、各第１支持体２６ａで夫々支持されるように基板Ｓｗをイオン注入しようとする主面がＺ軸方向上方を向く姿勢にしてセットする。 After installing the cassette Ct in which 24 substrates Sw are set in the load lock chamber Lc in the air atmosphere, the load lock chamber Lc is evacuated by a vacuum pump. At this time, the inside of the vacuum chamber 1 is evacuated by a vacuum pump to a predetermined pressure, and the stages 2a and 2b are in a horizontal posture, respectively. When the inside of the load lock chamber Lc is evacuated to a predetermined pressure, the gate valve Gv is opened, the substrate Sw is sequentially taken out from the cassette Ct by the vacuum transfer robot Rb, and the rotating plate 25 is moved in the horizontal posture stages 2a and 2b. While rotating as appropriate, the substrate Sw is set in a posture in which the main surface to be ion-implanted faces upward in the Z-axis direction so as to be supported by each of the first supports 26a.

次に、図示省略のモータにより回転軸２２を回転駆動して各ステージ２ａ，２ｂの回転板２５を夫々揺動させ、水平姿勢から起立姿勢にする。このとき、各基板Ｓｗはその主面がイオン照射室１ｂを向く姿勢となり、その側面が第２支持体２６ｂに当接して回転板２５から脱落しないように支持される。そして、第１ステージ２ａにて、回転板２５の照射位置Ｒｐにある静止状態の第１基板Ｓｗの主面に対し、イオンビーム照射ユニットＩｕの加速器４１ａにより加速することで所定の注入エネルギに制御したイオンビームが照射され、その主面全面に亘ってＸ軸方向及びＺ軸方向にそれぞれ走査してその表面から所定の深さ位置にイオン注入する。このとき、所定のドーズ量が得られる基板Ｓｗへのイオンビームの照射時間を総処理時間とし、総処理時間より短く設定した単位処理時間でイオン注入される（第１工程）。この場合の単位処理時間は、イオンビーム照射時の基板Ｓｗの温度上昇速度、回転板２５にセットされる基板Ｓｗの枚数、一回のイオン注入が行われた基板Ｓｗが、次にイオン注入のために照射位置Ｒｐに移動されるまでの基板Ｓｗの温度下降速度などを考慮して適宜設定される。ＬＮ基板に対して水素イオンやヘリウムイオンをイオン注入するような場合には、単位処理時間は数秒に設定される。 Next, the rotating shaft 22 is rotationally driven by a motor (not shown) to swing the rotating plates 25 of the stages 2a and 2b, respectively, from the horizontal posture to the standing posture. At this time, each substrate Sw is in a posture in which its main surface faces the ion irradiation chamber 1b, and its side surface abuts on the second support 26b and is supported so as not to fall off from the rotating plate 25. Then, in the first stage 2a, the main surface of the stationary first substrate Sw at the irradiation position Rp of the rotating plate 25 is accelerated by the accelerator 41a of the ion beam irradiation unit Iu to control the implantation energy to a predetermined value. The ion beam is irradiated, and the entire main surface thereof is scanned in the X-axis direction and the Z-axis direction, respectively, and ions are implanted from the surface to a predetermined depth position. At this time, the irradiation time of the ion beam on the substrate Sw from which the predetermined dose amount is obtained is set as the total processing time, and the ions are implanted in the unit processing time set shorter than the total processing time (first step). In this case, the unit processing time is the rate of temperature rise of the substrate Sw at the time of ion beam irradiation, the number of substrates Sw set on the rotating plate 25, the substrate Sw in which one ion implantation is performed, and then the ion implantation. Therefore, it is appropriately set in consideration of the temperature drop rate of the substrate Sw until it is moved to the irradiation position Rp. When ion-implanting hydrogen ions or helium ions into the LN substrate, the unit processing time is set to several seconds.

次に、第１ステージ２ａにて第１基板Ｓｗに対するイオン注入が終了すると、ビーム偏向器４３によってイオンビームの出射方向をかえて、第２ステージ２ｂにて、回転板２５の照射位置Ｒｐにある静止状態の第１基板Ｓｗに対し、上記同様、イオンビームを照射してイオン注入される（第２工程）。第２工程を実施している間において、第１ステージ２ａでは、回転板２５が所定角（本実施形態では、３０度）だけ回転され、一回目のイオン注入が終了した第１基板Ｓｗに代えて、これに隣接する（即ち、次にイオン注入される）第２基板Ｓｗが照射位置Ｒｐに移動される（第３工程）。一方、第２ステージ２ｂにて、第１基板Ｓｗに対するイオン注入が終了すると、ビーム偏向器４３によってイオンビームの出射方向をかえて、第１ステージ２ａにて、回転板２５の照射位置Ｒｐにある静止状態の第２基板Ｓｗに対し、上記同様、イオンビームを照射してイオン注入する。 Next, when the ion implantation into the first substrate Sw is completed in the first stage 2a, the emission direction of the ion beam is changed by the beam deflector 43, and the ion beam is located at the irradiation position Rp of the rotating plate 25 in the second stage 2b. The stationary first substrate Sw is irradiated with an ion beam and ion-implanted in the same manner as described above (second step). During the second step, in the first stage 2a, the rotating plate 25 is rotated by a predetermined angle (30 degrees in this embodiment) to replace the first substrate Sw, which has completed the first ion implantation. Then, the second substrate Sw adjacent to this (that is, the ion is implanted next) is moved to the irradiation position Rp (third step). On the other hand, when the ion implantation into the first substrate Sw is completed in the second stage 2b, the emission direction of the ion beam is changed by the beam deflector 43, and the ion beam is located at the irradiation position Rp of the rotating plate 25 in the first stage 2a. The second substrate Sw in the stationary state is irradiated with an ion beam and ion-implanted in the same manner as described above.

上記に併せて、第２ステージ２ｂでは、回転板２５が所定角（本実施形態では、３０度）だけ回転され、一回目のイオン注入が終了した第１基板Ｓｗに代えて、これに隣接する（即ち、次にイオン注入される）第２基板Ｓｗが照射位置Ｒｐに移動される。そして、第１及び第２の両ステージ２ａ，２ｂの各基板Ｓｗに対して、イオンビームの照射時間が総処理時間に達するまで上記手順が繰り返され、各基板Ｓｗに対して所定のドーズ量でイオン注入される。 In addition to the above, in the second stage 2b, the rotating plate 25 is rotated by a predetermined angle (30 degrees in the present embodiment), and is adjacent to the first substrate Sw where the first ion implantation is completed. The second substrate Sw (that is, ion-implanted next) is moved to the irradiation position Rp. Then, the above procedure is repeated for each substrate Sw of both the first and second stages 2a and 2b until the irradiation time of the ion beam reaches the total processing time, and the dose amount is predetermined for each substrate Sw. Ion implantation.

ここで、一回のイオン注入が行われた各基板Ｓｗは、次にイオン注入のために照射位置Ｒｐに移動されるまでは、何らの入熱もなく、また、冷却パネル３に対峙する位置では、放射により冷却される。このため、次にイオン注入のために照射位置に基板Ｓｗが移動されたときには、基板Ｓｗは、一回のイオン注入が実施される前と同等の温度まで下降している。 Here, each substrate Sw on which one ion implantation has been performed has no heat input until it is moved to the irradiation position Rp for ion implantation, and is in a position facing the cooling panel 3. Then, it is cooled by radiation. Therefore, the next time the substrate Sw is moved to the irradiation position for ion implantation, the substrate Sw drops to the same temperature as before one ion implantation was performed.

以上の実施形態によれば、一枚の基板Ｓｗに対して、複数回に分けてイオンビームを照射してイオン注入すると共に、各基板Ｓｗの一回のイオン注入後には照射位置Ｒｐから一旦移動させ、その間には冷却パネル３によって放射冷却されることで、次に照射位置Ｒｐに移動されるまでに基板Ｓｗの主面の温度を確実に下げることができる一方で、その間には、各ステージ２ａ，２ｂに配置されている各基板Ｓｗに対してイオン注入が順次行われる。その結果、基板Ｓｗの温度を所定温度以上に上昇させることなく、高い量産性で複数枚の基板Ｓｗに対してイオン注入することが可能になる。 According to the above embodiment, one substrate Sw is irradiated with an ion beam in a plurality of times to implant ions, and after one ion implantation of each substrate Sw, the substrate is temporarily moved from the irradiation position Rp. In the meantime, the temperature of the main surface of the substrate Sw can be surely lowered by the time it is moved to the irradiation position Rp by radiating cooling by the cooling panel 3, while each stage is in the meantime. Ion implantation is sequentially performed on each substrate Sw arranged in 2a and 2b. As a result, it is possible to implant ions into a plurality of substrates Sw with high mass productivity without raising the temperature of the substrate Sw to a predetermined temperature or higher.

また、基板Ｓｗを第１及び第２の支持体２６ａ，２６ｂで支持する構成を採用したため、イオン注入により分極してステージ２ａ，２ｂ表面に静電吸着するといった不具合の発生を防止でき、その結果、イオン注入時における基板Ｓｗの破損を防止でき、しかも、真空搬送ロボットＲｂによる処理済みの基板Ｓｗの円滑な搬出が阻害されることはない。本実施形態では、第１支持体２６ａで基板Ｓｗが所定高さに支持されるため、その長さやその配置を適宜設定しておけば、真空搬送ロボットＲｂによって回転板２５の基板支持部２６に基板Ｓｗを受け渡すときに、基板Ｓｗを所定高さに持ち上げるリフト手段等を不要にでき、有利である。 Further, since the substrate Sw is supported by the first and second supports 26a and 26b, it is possible to prevent the occurrence of problems such as polarization by ion implantation and electrostatic adsorption on the surfaces of the stages 2a and 2b. It is possible to prevent the substrate Sw from being damaged during ion implantation, and the smooth removal of the processed substrate Sw by the vacuum transfer robot Rb is not hindered. In the present embodiment, the substrate Sw is supported at a predetermined height by the first support 26a. Therefore, if the length and arrangement thereof are appropriately set, the vacuum transfer robot Rb can be used to support the substrate 26 of the rotating plate 25. When delivering the substrate Sw, it is possible to eliminate the need for a lifting means or the like for lifting the substrate Sw to a predetermined height, which is advantageous.

以上、本発明の実施形態について説明したが、本発明の技術思想の範囲を逸脱しない限り、種々の変形が可能である。上記実施形態では、真空チャンバ１壁面に冷却パネル３を設けたものを例に説明したが、これに限定されるものではなく、イオン注入しようとする基板によってはこれを省略できる一方で、回転板の上面に冷却手段を設け、基板支持部２６で支持される基板Ｓｗが冷却されるようにしてもよい。また、上記実施形態では、２個のステージ２ａ，２ｂを設けたものを例に説明したが、複数枚の基板Ｓｗを支持するステージを３個以上とし、上記操作に従い、各ステージで支持された各基板Ｓｗに対して順次イオンビームを照射してイオン注入することもできる。 Although the embodiments of the present invention have been described above, various modifications can be made without departing from the scope of the technical idea of the present invention. In the above embodiment, the case where the cooling panel 3 is provided on the wall surface of the vacuum chamber 1 has been described as an example, but the present invention is not limited to this, and this can be omitted depending on the substrate to which ion implantation is to be performed. A cooling means may be provided on the upper surface of the substrate to cool the substrate Sw supported by the substrate support portion 26. Further, in the above embodiment, the case where the two stages 2a and 2b are provided has been described as an example, but the number of stages supporting a plurality of substrates Sw is set to three or more, and the stages are supported by each stage according to the above operation. It is also possible to sequentially irradiate each substrate Sw with an ion beam to implant ions.

また、上記実施形態では、回転板２５に複数枚の基板Ｓｗをセットし、回転板２５の回転により基板Ｓｗが順次照射位置Ｒｐに移動されるものを例に説明したが、基板Ｓｗが順次照射位置Ｒｐに移動されるものであれば、これに限定されるものではなく、同一平面内で基板Ｓｗが水平移動するようにしてもよい。更に、上記実施形態では、ＬＮ基板に水素イオンや希ガスのイオンをイオン注入する場合を例に説明したが、基板は、ＬＮ基板に限られるものではなく、ＬＴ（ＬｉＴａＯ_３）基板などの他の半導体単結晶ウエハの主面に所定のイオンを注入する場合にも適用でき、特に、イオン注入により容易に分極してしまう基板に対してイオンを注入する場合に有効である。 Further, in the above embodiment, a plurality of substrates Sw are set on the rotating plate 25, and the substrate Sw is sequentially moved to the irradiation position Rp by the rotation of the rotating plate 25. However, the substrate Sw is sequentially irradiated. As long as it is moved to the position Rp, the present invention is not limited to this, and the substrate Sw may be moved horizontally in the same plane. Further, in the above embodiment, the case of ion-implanting hydrogen ions or rare gas ions into the LN substrate has been described as an example, but the substrate is not limited to the LN substrate, and other substrates such as an LT (LiTaO ₃ ) substrate and the like. It can also be applied when a predetermined ion is implanted into the main surface of the semiconductor single crystal wafer of the above, and is particularly effective when the ion is implanted into a substrate which is easily polarized by ion implantation.

ＩＭ…イオン注入装置、Ｒｐ…照射位置、Ｓｗ…基板、１…真空チャンバ、２ａ，２ｂ…ステージ、２５…回転板、２６…基板支持部（支持体）、２６ａ…第１支持体、２６ｂ…第２支持体、３…冷却パネル（冷却手段）、４１ａ…加速器。 IM ... ion implanter, Rp ... irradiation position, Sw ... substrate, 1 ... vacuum chamber, 2a, 2b ... stage, 25 ... rotating plate, 26 ... substrate support (support), 26a ... first support, 26b ... 2nd support, 3 ... cooling panel (cooling means), 41a ... accelerator.

Claims

Multiple substrates are placed on at least two stages that are spaced apart from each other in the vacuum chamber.
Two directions orthogonal to each other in the substrate surface are defined as the X-axis direction and the Y-axis direction, and a predetermined value is obtained by accelerating the main surface of any one of the stationary substrates installed on any one stage with an accelerator. The total processing time is the irradiation time of the ion beam on the substrate that irradiates the implanted energy with the controlled ion beam to obtain a predetermined dose amount, and the unit processing time is set shorter than the total processing time in the X-axis direction and the Y-axis direction. The first step of scanning and implanting ions
By changing the emission direction of the ion beam, the main surface of any one of the stationary substrates installed on the other stage is irradiated with the ion beam, and the ion beam is irradiated in the X-axis direction and the Y-axis direction in a unit processing time. The second step of scanning and ion implantation,
The position of the stage where the ion beam is irradiated to the substrate is set as the irradiation position, and between the first step and the second step, another substrate is irradiated instead of the substrate ion-implanted by the stage in a unit processing time. Including the third step of moving to
An ion implantation method characterized in that the first step, the second step, and the third step are repeated a plurality of times until the unit treatment time reaches the total treatment time.

The ion implantation method according to claim 1, further comprising a cooling step of cooling the substrate, which is ion-implanted in the first step, until the substrate is next moved to the irradiation position.

The ion implantation method according to claim 1 or 2, wherein the substrate is supported by a support erected on the stage in the first step and the second step.

In an ion implantation apparatus that enables the implementation of the ion implantation method according to any one of claims 1 to 3.
The stage includes a rotatable rotating plate that supports a plurality of the substrates at intervals in the circumferential direction, and a first support and a substrate that can abut on one surface of the rotating plate and the back surface of the substrate. A second support that can be brought into contact with the outer surface of the first support is erected, and the substrate supported by the first support and the second support is sequentially moved to the irradiation position by the rotation of the rotating plate. An ion implanter characterized by the fact that it has been used.

The ion implantation apparatus according to claim 4, further comprising a cooling means for cooling the substrate at a position other than the irradiation position by radiation, which is provided facing the rotating plate.