JP3888142B2

JP3888142B2 - Method for synthesizing compound semiconductor polycrystal

Info

Publication number: JP3888142B2
Application number: JP2001355587A
Authority: JP
Inventors: 保至菅野
Original assignee: Sumitomo Metal Mining Co Ltd
Current assignee: Sumitomo Metal Mining Co Ltd
Priority date: 2001-11-21
Filing date: 2001-11-21
Publication date: 2007-02-28
Anticipated expiration: 2021-11-21
Also published as: JP2003160315A

Description

【０００１】
【発明の属する技術分野】
本発明は、ＧａＰ等III−Ｖ族化合物半導体多結晶の合成方法に係り、特に、合成用ボート内に充填されたIII族原料がボート本体と蓋材との螺着部位へ漏出する現象を防止できると共に、合成終了後に蓋材をボート本体から外す際の合成用ボートの欠けや破損も防止されてその再使用寿命の改善が図れるIII−Ｖ族化合物半導体多結晶の合成方法に関するものである。
【０００２】
【従来の技術】
ＧａＰ等のIII−Ｖ族化合物半導体は、従来、レーザダイオード、発光ダイオードのようなオプトデバイスやＨＥＭＴのような高速デバイス等の材料に利用されている。
【０００３】
そして、このようなIII−Ｖ族化合物半導体は、Ｇａ等のIII族原料とＰ等のＶ族原料を直接反応させて単結晶を成長させることが困難なため、III−Ｖ族化合物半導体多結晶をまず合成し、次いでこのIII−Ｖ族化合物半導体多結晶を用いてＬＥＣ法等によりIII−Ｖ族化合物半導体単結晶を成長させる方法が採られている。
【０００４】
ところで、上記III−Ｖ族化合物半導体多結晶は、図２に示すように各原料が充填された石英等から成る封管１を横型高圧炉２内に搬入して合成する方法が採られている。
【０００５】
すなわち、図２に示すようにＧａ等のIII族原料３は、スリット５１が設けられた合成用ボート４（図３参照）内に充填されると共に、ボート４全体を石英等から成る内管５内に収容して上記封管１の一端側に配置され、Ｐ等のＶ族原料６は、熱遮蔽板７を介し上記封管１の他端側に配置される。尚、原料等が充填された封管１は、その後真空にして封じ切られる。
【０００６】
次に、真空にして封じ切られた上記封管１は、中央に高周波コイル８を有しこの高周波コイル８を中央に挟んでその両側に抵抗ヒータ９を有する高圧容器にて構成された横型高圧炉２内に搬入される。
【０００７】
そして、横型高圧炉２内において封管１全体が加熱され、高周波コイル８により合成用ボート４内のIII族原料３が局所的に更に高温に加熱されると共に、Ｖ族原料６から発生した原料ガスが上記熱遮蔽板７に取付けられた導入管１０を介し内管５内に導入されて上記III族原料３と反応し、かつ、上記封管１を矢印α方向へ横型高圧炉２内を移動させるか封管１を固定して上記横型高圧炉２を逆方向へ移動させる等して（すなわち、高温部を相対移動させる）III−Ｖ族化合物半導体多結晶が合成される。
【０００８】
【発明が解決しようとする課題】
ところで、III−Ｖ族化合物半導体多結晶の合成方法に用いられる合成用ボート４は、図３および図４に示すように上部長手方向に直線状のスリット５１が開設された円筒状ボート本体５０とこのボート本体５０の両開放端に螺着される蓋材６０とでその主要部が構成されており、上記スリット５１のみが開放されて原料ガスがボート４内に出入りできるようになっている。
【０００９】
そして、上記蓋材６０とボート本体５０に設けられた螺子部を介して互いに螺着される構造になっているため、蓋材６０の螺子部やボート本体５０の螺子部に欠けが存在したり緩みが生ずると、これ等螺着部位に隙間ができ、合成用ボート４内に充填されたIII族原料が上記螺着部位へ漏出することがあった。
【００１０】
この状態でIII−Ｖ族化合物半導体多結晶の合成を行った場合、上記螺着部位へ漏出したIII族原料の一部とＶ族の原料ガスとがこの部位で反応してIII−Ｖ族化合物半導体多結晶を生成してしまうことがあり、螺着部位に生成した上記結晶が原因となって化合物半導体多結晶の合成を終了した時点でボート本体５０から蓋材６０を外す場合に蓋材６０が外れ難くなる問題を有していた。
【００１１】
尚、ボート本体５０から蓋材６０を強引に外そうとした場合、合成用ボート４に欠けや破損が発生し易く、合成用ボート４の再使用が阻害されてIII−Ｖ族化合物半導体多結晶の製造コストを上昇させる問題があつた。
【００１２】
また、蓋材６０近傍にIII族原料が未反応状態で残留した場合、未反応のIII族原料を介し合成されたIII−Ｖ族化合物半導体多結晶と蓋材６０とが接着してしまうことがあり、上記同様、蓋材６０を強引に外そうとした場合、合成用ボート４に欠けや破損が発生し易く、合成用ボート４の再使用が阻害されてIII−Ｖ族化合物半導体多結晶の製造コストを上昇させる問題があつた。
【００１３】
本発明はこの様な問題点に着目してなされたもので、その課題とするところは、ボート内に充填されたIII族原料がボート本体と蓋材との螺着部位へ漏出する現象を防止できると共に、合成終了後に蓋材をボート本体から外す際の合成用ボートの欠けや破損も防止されてその再使用寿命の改善が図れるIII−Ｖ族化合物半導体多結晶の合成方法を提供することにある。
【００１４】
【課題を解決するための手段】
すなわち、請求項１に係る発明は、
上部長手方向に直線状のスリットが開設された円筒状ボート本体とこのボート本体の両開放端に螺着される蓋材とでその主要部が構成されるボート内にIII族原料を充填し、このボートを封管内の一端側に配置する一方、封管内の他端側にはＶ族原料を配置し、上記封管全体を加熱すると共にボート内のIII族原料を局所的に更に高温に加熱してＶ族原料から発生した原料ガスと上記III族原料を反応させ、かつ、上記高温部を徐々に相対移動させながらIII−Ｖ族化合物半導体多結晶を合成する化合物半導体多結晶の合成方法を前提とし、
ボート本体の両開放端側筒壁面にその開放縁部から上記スリット端方向へ延びる帯状切欠部をそれぞれ設けると共に、ボート本体の開放面よりわずかに大きくかつその外周縁の一部に上記帯状切欠部に嵌合される突起片が設けられた円形若しくは多角形状の耐熱性フィルム体を間に介在させた状態でボート本体の両開放端に蓋材をそれぞれ螺着して上記ボートが構成されていることを特徴とし、
請求項２に係る発明は、
請求項１記載の発明に係る化合物半導体多結晶の合成方法を前提とし、
上記ボート本体並びに蓋体が黒鉛で構成され、かつ、耐熱性フィルム体がカーボンフィルムで構成されていることを特徴とするものである。
【００１５】
そして、これ等請求項１〜２記載の発明に係る化合物半導体多結晶の合成方法によれば、
ボート本体の両開放端側筒壁面にその開放縁部から上記スリット端方向へ延びる帯状切欠部をそれぞれ設けると共に、ボート本体の開放面よりわずかに大きくかつその外周縁の一部に上記帯状切欠部に嵌合される突起片が設けられた円形若しくは多角形状の耐熱性フィルム体を間に介在させた状態でボート本体の両開放端に蓋材をそれぞれ螺着して上記ボートが構成されているため、蓋材の螺子部やボート本体の螺子部に欠けが存在したり緩みが生じてこれ等螺着部位に隙間ができても、蓋材とボート本体の開放端間に介在された上記耐熱性フィルム体の作用によりボート内に充填されたIII族原料が上記螺着部位へ漏出することがなく、更に、上記蓋材近傍にIII族原料が未反応状態で残留した場合でも、上記耐熱性フィルム体の作用により合成されたIII−Ｖ族化合物半導体多結晶と蓋材とが接着してしまうこともない。
【００１６】
従って、化合物半導体多結晶の合成を終了した時点で蓋材をボート本体から容易に外すことができ、かつ、上記ボートの再使用が阻害されることもない。
【００１７】
【発明の実施の形態】
以下、本発明の実施の形態について、図面を参照して詳細に説明する。
【００１８】
すなわち、この実施の形態に係る化合物半導体多結晶の合成方法は、III族原料を充填するボートが図１に示すような構造に変更されている点を除き従来の合成方法と略同一である。
【００１９】
まず、ボート４は、図１に示すように筒壁面の上部長手方向に直線状のスリット５１が開設されかつ両開放端側筒壁面に上記スリット５１より広幅で筒壁開放縁部から延びてスリット５１端に接続される帯状切欠部５２がそれぞれ設けられた黒鉛製の円筒状ボート本体５０と、この円筒状ボート本体５０の両開放端にそれぞれ螺着される黒鉛製の蓋材６０と、上記円筒状ボート本体５０と蓋材６０との間に介在され円筒状ボート本体５０の内径よりわずかに大きい直径を有しかつその外周縁の一部に上記帯状切欠部５２に嵌合される突起片７１を有する円形状の耐熱性フィルム体７０とでその主要部が構成され、このボート４内には図２に示すようにIII族原料３が充填されている。
【００２０】
そして、上記III族原料３が充填されたボート４は石英内管５内に収納され、図２に示すように石英内管５毎、石英封管（外管）１内の一端側に配置されると共に、石英封管１の他端側にはＶ族原料６が配置され、かつ、石英封管１の略中央部には不透明石英製の熱遮蔽板７が配置される。尚、熱遮蔽板７には導入管１０が取付けられており、この導入管１０を介してＶ族原料６が配置された空間と石英内管５とが連通するようになっている。
【００２１】
次に、石英内管５、熱遮蔽板７およびＶ族原料６等が収納された石英封管（外管）１の口を塞ぎ、真空引きを行なった後、封止切る。
【００２２】
次に、中央に高周波コイル８を有しこの高周波コイル８を中央に挟んでその両側に抵抗ヒータ９を有する高圧容器にて構成された横型高圧炉２内に、封じ切られた上記石英封管（外管）１を搬入し、横型高圧炉２の高圧容器内に窒素等不活性ガスを充填して高圧炉内を高圧状態に設定した後、抵抗ヒータ９を作用させて石英封管（外管）１全体を加熱し、かつ、高周波コイル８を作用させてボート４内におけるIII族原料３を局所的に更に高温に加熱する。
【００２３】
そして、熱遮蔽板７に取付けられた導入管１０を介し上記石英内管５内に導入されたＶ族原料６からの原料ガスとボート４内におけるIII族原料３とを反応させ、かつ、上記石英封管（外管）１若しくは横型高圧炉２を移動（すなわち、高温部を相対移動）させ、ボート４内で上記反応を順次進行させてIII−Ｖ族化合物半導体多結晶を合成する。
【００２４】
この実施の形態に係る合成方法によれば、ボート本体５０の両開放端側筒壁面にスリット５１より広幅で筒壁開放縁部から延びてスリット５１端に接続される帯状切欠部５２がそれぞれ設けられていると共に、ボート本体５０の内径よりわずかに大きい直径を有しかつその外周縁の一部に上記帯状切欠部５２に嵌合される突起片７１を設けた円形状の耐熱性フィルム体７０を間に介在させた状態でボート本体５０の両開放端に蓋材６０がそれぞれ螺着されているため、蓋材６０の螺子部やボート本体５０の螺子部に欠けが存在したり緩みが生じてこれ等螺着部位に隙間ができていても、蓋材６０とボート本体５０の開放端間に介在された上記耐熱性フィルム体７０の作用によりボート４内に充填されたIII族原料３が上記螺着部位へ漏出することがなく、更に、上記蓋材６０近傍にIII族原料３が未反応状態で残留した場合でも、上記耐熱性フィルム体７０の作用により合成されたIII−Ｖ族化合物半導体多結晶と蓋材６０とが接着してしまうこともない。
【００２５】
従って、化合物半導体多結晶の合成を終了した時点で蓋材６０をボート本体５０から外す際に、従来のように蓋材６０が外れ難くなるようなことがなく、ボート４の再使用が阻害されるようなこともない利点を有している。
【００２６】
尚、ボート本体５０の両開放端側筒壁面に設けられる上記帯状切欠部５２の幅寸法についてはスリット５１と同一幅若しくは狭幅であってもよく、また、帯状切欠部５２がスリット５１端に必ずしも接続される必要はない。
【００２７】
また、上記耐熱性フィルム体７０の材質としては、例えば、カーボンフィルムや熱分解窒化ホウ素（ｐ−ＢＮ）製フィルム等が挙げられる。また、耐熱性フィルム体７０の直径はボート本体５０の内径よりもわずかに大きければよく、この耐熱性フィルム体７０を蓋材６０とボート本体５０の開放端間に介在させることによりボート４内に充填されたIII族原料３が螺着部位へ漏出しなくなるような寸法なら任意である。尚、ボート４内に充填されたIII族原料３の上記螺着部位への漏出が防止されるなら耐熱性フィルム体７０の形状は円形状に限定されるものではなく、例えば、ボート本体の開放面よりわずかに大きい正八角形状など多角形状であってもよい。更に、上記耐熱性フィルム体７０の外周縁に設けられる突起片７１の幅寸法についても、この突起片７１がボート本体５０の上記帯状切欠部５２に嵌合されてボート４内で保持されればよくこれ等寸法も任意である。
【００２８】
【実施例】
以下、本発明の実施例について具体的に説明する。
【００２９】
まず、図１に示す黒鉛製ボート本体５０の内径よりわずかに大きい、直径４２ｍｍ、厚さ０．４ｍｍのカーボンフィルム製耐熱性フィルム体７０を間に介在させた状態で上記黒鉛製ボート本体５０の両開放端に蓋材６０をそれぞれ螺着させて合成用ボート４を組み立てた。
【００３０】
尚、図２に示すようにこのボート４は外径４８ｍｍ、内径４０ｍｍ、長さ７４５ｍｍの寸法を有しており、この内部にIII族原料３であるガリウム（Ｇａ）２０００ｇが２等分して充填されている。
【００３１】
次に、III族原料３が充填され黒鉛製ボート４を石英内管５内に収納し、図１に示すように石英内管５毎、石英封管１内の一端側に配置すると共に、石英封管１の他端側にはＶ族原料６である赤燐（Ｐ）９２０ｇを配置した。尚、石英封管１内には、Ｖ族原料６の原料ガスを石英内管５内に導入するための導入管１０が取付けられた不透明石英製の熱遮蔽板７が配置されている。
【００３２】
次に、石英内管５、熱遮蔽板７およびＶ族原料６等が収納された石英封管１の口を塞ぎ、中を１０^-6Ｔｏｒｒオーダまで真空引きを行なった後、封止切る。
【００３３】
次に、中央に高周波コイル８を有しこの高周波コイル８を中央に挟んでその両側に抵抗ヒータ９を有する高圧容器にて構成された横型高圧炉２内に、封じ切られた上記石英封管１を搬入し、横型高圧炉２の高圧容器内に窒素ガスを充填して高圧炉内を高圧状態（４０ｋｇ／ｃｍ²）に設定した後、抵抗ヒータ９を作用させ石英封管１全体を加熱してＶ族原料６である赤燐（Ｐ）を３００℃〜７００℃に昇温し、かつ、ボート４内のIII族原料３であるガリウム（Ｇａ）を５００℃〜６００℃の範囲で保持すると共に、高周波コイル８を作用させて上記ボート４内をＧａＰの融点である１４７０℃付近の温度で保持する。
【００３４】
そして、熱遮蔽板７に取付けられた導入管１０を介し上記石英内管５内に導入されたＶ族原料６からの原料ガスとボート４の内におけるIII族原料３とを反応させ、かつ、上記石英封管１を矢印α方向へ横型高圧炉２内を移動させ（すなわち、高温部を相対移動させ）、ボート４内で上記反応を順次進行させて一体化されたIII−Ｖ族化合物半導体（ＧａＰ）多結晶を合成した。
【００３５】
一方、比較例としてカーボンフィルム製耐熱性フィルム体７０を間に介在させない従来のボートも組み立て、かつ、合成条件は実施例と同一にしてIII−Ｖ族化合物半導体（ＧａＰ）多結晶を合成した。
【００３６】
そして、実施例と比較例に係るIII−Ｖ族化合物半導体（ＧａＰ）多結晶の合成を繰り返し行い、III族原料であるガリウム（Ｇａ）の漏れ状態、合成された多結晶と蓋材６０との接着状態、および、黒鉛製ボート４の再使用寿命（耐久性）を比較した。この結果を以下の表１に示す。
【００３７】
尚、表１において「原料漏れ発生率（％）」は繰り返し行った合成数に対して原料漏れが発生した数の割合、「蓋との接着発生率（％）」は上記合成数に対して合成されたIII−Ｖ族化合物半導体（ＧａＰ）多結晶と蓋材６０とが接着した数の割合である。また、「黒鉛ボートの破損率（％）」は合成数に対して合成されたIII−Ｖ族化合物半導体（ＧａＰ）多結晶を取り出すときに破損したボート数の割合、「平均使用回数（回）」は黒鉛ボート１個について合成に繰り返し使用した回数の平均回数である。
【００３８】
【表１】

表１に示された数値から明らかなように、実施例においてはIII族原料であるガリウム（Ｇａ）の漏れ、合成されたIII−Ｖ族化合物半導体（ＧａＰ）多結晶と蓋材６０との接着はほとんどない状態となり、接着の発生率は大幅に低下していることが確認される。
【００３９】
また、実施例における黒鉛ボートの破損率は０．７％となり、比較例の１８．２％から大きく低下し、かつ、実施例における黒鉛ボートの平均使用回数についても６．５回となり比較例の２．４回に較べて著しく向上していることが確認される。
【００４０】
【発明の効果】
請求項１〜２記載の発明に係る化合物半導体多結晶の合成方法によれば、
ボート本体の両開放端側筒壁面にその開放縁部から上記スリット端方向へ延びる帯状切欠部をそれぞれ設けると共に、ボート本体の開放面よりわずかに大きくかつその外周縁の一部に上記帯状切欠部に嵌合される突起片が設けられた円形若しくは多角形状の耐熱性フィルム体を間に介在させた状態でボート本体の両開放端に蓋材をそれぞれ螺着して上記ボートが構成されているため、蓋材の螺子部やボート本体の螺子部に欠けが存在したり緩みが生じてこれ等螺着部位に隙間ができても、蓋材とボート本体の開放端間に介在された上記耐熱性フィルム体の作用によりボート内に充填されたIII族原料が上記螺着部位へ漏出することがなく、更に、上記蓋材近傍にIII族原料が未反応状態で残留した場合でも、上記耐熱性フィルム体の作用により合成されたIII−Ｖ族化合物半導体多結晶と蓋材とが接着してしまうこともない。
【００４１】
従って、化合物半導体多結晶の合成を終了した時点で蓋材をボート本体から容易に外すことができるためボートの欠けや破損を防止することが可能となり、これによりボートの再使用寿命の大幅な改善が図れる効果を有する。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る化合物半導体多結晶の合成方法に適用されるボートの一部分解斜視図。
【図２】 III−Ｖ族化合物半導体多結晶の合成方法を示す説明図。
【図３】従来例に係るIII−Ｖ族化合物半導体多結晶の合成方法に適用されるボートの概略斜視図。
【図４】従来例に係るIII−Ｖ族化合物半導体多結晶の合成方法に適用されるボートの一部分解斜視図。
【符号の説明】
４ボート
５０ボート本体
５１スリット
５２帯状切欠部
６０蓋材
７０耐熱性フィルム体
７１突起片[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for synthesizing a group III-V compound semiconductor polycrystal such as GaP, and in particular, prevents a phenomenon in which a group III raw material filled in a synthesis boat leaks into a screwed portion between a boat body and a lid. Further, the present invention relates to a method for synthesizing a group III-V compound semiconductor polycrystal which can prevent chipping or breakage of the synthesis boat when the lid member is removed from the boat body after the synthesis is completed and can improve its reuse life.
[0002]
[Prior art]
Conventionally, III-V group compound semiconductors such as GaP have been used as materials for optical devices such as laser diodes and light-emitting diodes and high-speed devices such as HEMTs.
[0003]
Since such a III-V compound semiconductor is difficult to grow a single crystal by directly reacting a group III material such as Ga and a group V material such as P, a III-V compound semiconductor polycrystal Is first synthesized, and then a group III-V compound semiconductor single crystal is grown by the LEC method using this group III-V compound semiconductor polycrystal.
[0004]
By the way, as shown in FIG. 2, the III-V group compound semiconductor polycrystal is synthesized by bringing a sealed tube 1 made of quartz or the like filled with each raw material into a horizontal high pressure furnace 2 and synthesizing it. .
[0005]
That is, as shown in FIG. 2, the group III raw material 3 such as Ga is filled in a synthesis boat 4 (see FIG. 3) provided with slits 51 and the entire boat 4 is made of an inner tube 5 made of quartz or the like. The V group raw material 6 such as P is disposed on the other end side of the sealed tube 1 via the heat shielding plate 7 and accommodated in one end side of the sealed tube 1. The sealed tube 1 filled with the raw materials and the like is then vacuumed and sealed.
[0006]
Next, the sealed tube 1 that has been sealed in a vacuum is a horizontal high-pressure vessel that is composed of a high-pressure vessel having a high-frequency coil 8 in the center and sandwiching the high-frequency coil 8 in the center and having resistance heaters 9 on both sides thereof. It is carried into the furnace 2.
[0007]
The entire sealed tube 1 is heated in the horizontal high-pressure furnace 2, and the group III material 3 in the synthesis boat 4 is locally heated to a higher temperature by the high frequency coil 8, and the material generated from the group V material 6 Gas is introduced into the inner pipe 5 through the introduction pipe 10 attached to the heat shielding plate 7 to react with the group III raw material 3, and the sealed pipe 1 is moved in the horizontal high-pressure furnace 2 in the direction of arrow α. The group III-V compound semiconductor polycrystal is synthesized by moving or fixing the sealed tube 1 and moving the horizontal high pressure furnace 2 in the opposite direction (that is, relatively moving the high temperature part).
[0008]
[Problems to be solved by the invention]
By the way, the synthesis boat 4 used in the method for synthesizing the III-V compound semiconductor polycrystal has a cylindrical boat body 50 in which a straight slit 51 is opened in the upper longitudinal direction as shown in FIGS. And the lid member 60 screwed to both open ends of the boat main body 50 constitute the main part, and only the slit 51 is opened so that the source gas can enter and exit the boat 4. .
[0009]
Since the lid 60 and the boat body 50 are screwed to each other via a screw portion, the screw portion of the lid member 60 and the screw portion of the boat main body 50 are chipped. When loosening occurs, gaps are formed in these screwing sites, and the group III material filled in the synthesis boat 4 may leak to the screwing sites.
[0010]
When the III-V compound semiconductor polycrystal is synthesized in this state, a part of the group III source material leaked to the screwing site reacts with the group V source gas at this site, so that the group III-V compound is produced. When the cover 60 is removed from the boat body 50 at the time when the synthesis of the compound semiconductor polycrystal is finished due to the crystal generated at the screwing site in some cases, the semiconductor 60 may be formed. Had the problem of becoming difficult to come off.
[0011]
If the cover 60 is forcibly removed from the boat body 50, the synthesis boat 4 is likely to be chipped or damaged, and the reuse of the synthesis boat 4 is hindered, and the III-V compound semiconductor polycrystal There was a problem of increasing the manufacturing cost of
[0012]
Further, when the group III raw material remains in an unreacted state in the vicinity of the lid 60, the III-V group compound semiconductor polycrystal synthesized through the unreacted group III raw material may adhere to the lid 60. In the same manner as described above, when the lid 60 is forcibly removed, the synthesis boat 4 is likely to be chipped or damaged, and the reuse of the synthesis boat 4 is hindered. There was a problem of increasing manufacturing costs.
[0013]
The present invention has been made paying attention to such problems, and the problem is that the group III material filled in the boat is prevented from leaking into the screwed portion between the boat body and the lid. The present invention provides a method for synthesizing a III-V compound semiconductor polycrystal which can prevent chipping or breakage of the synthesis boat when removing the lid member from the boat body after synthesis and can improve its reuse life. is there.
[0014]
[Means for Solving the Problems]
That is, the invention according to claim 1
Group III raw material is filled into the boat, which consists of a cylindrical boat body with straight slits in the upper longitudinal direction and a lid member screwed to both open ends of the boat body. The boat is arranged on one end side in the sealed tube, while the V group material is arranged on the other end side in the sealed tube, and the entire sealed tube is heated and the group III material in the boat is locally heated to a higher temperature. A method for synthesizing a compound semiconductor polycrystal by reacting a source gas generated from a group V source by heating with the group III source and synthesizing a group III-V compound semiconductor polycrystal while gradually moving the high temperature portion relative to each other. Assuming
A strip-shaped notch extending from the open edge to the slit end direction is provided on both open end-side cylindrical wall surfaces of the boat body, and the strip-shaped notch is slightly larger than the open surface of the boat body and part of the outer periphery. The boat is configured by screwing lid members to both open ends of the boat body with a circular or polygonal heat-resistant film body provided with projection pieces fitted to the boat interposed therebetween. It is characterized by
The invention according to claim 2
Based on the method for synthesizing compound semiconductor polycrystal according to the invention of claim 1,
The boat body and the lid body are made of graphite, and the heat-resistant film body is made of a carbon film.
[0015]
According to the compound semiconductor polycrystal synthesis method according to the inventions according to claims 1 and 2,
A strip-shaped notch extending from the open edge to the slit end direction is provided on both open end-side cylindrical wall surfaces of the boat body, and the strip-shaped notch is slightly larger than the open surface of the boat body and part of the outer periphery. The boat is configured by screwing lid members to both open ends of the boat body with a circular or polygonal heat-resistant film body provided with projection pieces fitted to the boat interposed therebetween. Therefore, even if the screw part of the lid member or the screw part of the boat main body is chipped or loosened, and there is a gap between these screwed parts, the above heat resistance interposed between the cover member and the open end of the boat main body The group III raw material filled in the boat by the action of the conductive film body does not leak to the screwing site, and even when the group III raw material remains in an unreacted state in the vicinity of the lid member, the heat resistance Due to the action of the film body Is a Group III-V compound semiconductor polycrystalline and the lid member has no sometimes resulting in adhesion.
[0016]
Therefore, when the synthesis of the compound semiconductor polycrystal is finished, the lid member can be easily removed from the boat body, and the reuse of the boat is not hindered.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
That is, the method for synthesizing the compound semiconductor polycrystal according to this embodiment is substantially the same as the conventional synthesis method except that the boat filled with the group III material is changed to the structure shown in FIG.
[0019]
First, as shown in FIG. 1, the boat 4 is provided with a linear slit 51 in the upper longitudinal direction of the cylindrical wall surface and extends from the cylindrical wall open edge at a width wider than the slits 51 on both open end side cylindrical wall surfaces. A graphite cylindrical boat body 50 provided with strip-shaped notches 52 connected to the ends of the slits 51; a graphite lid member 60 screwed to both open ends of the cylindrical boat body 50; A protrusion that is interposed between the cylindrical boat body 50 and the lid member 60 and has a diameter slightly larger than the inner diameter of the cylindrical boat body 50 and is fitted to the strip-shaped notch 52 at a part of the outer peripheral edge thereof. The main part is comprised with the circular heat-resistant film body 70 which has the piece 71, and the III group raw material 3 is filled into this boat 4 as shown in FIG.
[0020]
The boat 4 filled with the group III raw material 3 is accommodated in the quartz inner tube 5 and is disposed on one end side in the quartz sealed tube (outer tube) 1 for each quartz inner tube 5 as shown in FIG. In addition, a group V material 6 is disposed on the other end side of the quartz sealed tube 1, and a heat shielding plate 7 made of opaque quartz is disposed at a substantially central portion of the quartz sealed tube 1. An introduction pipe 10 is attached to the heat shield plate 7, and the space in which the group V raw material 6 is disposed and the quartz inner pipe 5 communicate with each other through the introduction pipe 10.
[0021]
Next, the mouth of the quartz sealed tube (outer tube) 1 in which the quartz inner tube 5, the heat shielding plate 7, the group V raw material 6 and the like are stored is closed, vacuumed, and then sealed.
[0022]
Next, the quartz sealed tube sealed in a horizontal high pressure furnace 2 constituted by a high pressure vessel having a high frequency coil 8 in the center and sandwiching the high frequency coil 8 in the center and having resistance heaters 9 on both sides thereof. (Outer tube) 1 is carried in, and an inert gas such as nitrogen is filled in the high-pressure vessel of the horizontal high-pressure furnace 2 to set the inside of the high-pressure furnace to a high pressure state. Tube) 1 is heated, and the high frequency coil 8 is operated to heat the group III material 3 in the boat 4 locally to a higher temperature.
[0023]
Then, the raw material gas from the group V raw material 6 introduced into the quartz inner tube 5 through the introduction tube 10 attached to the heat shielding plate 7 is reacted with the group III raw material 3 in the boat 4, and The quartz sealed tube (outer tube) 1 or the horizontal high-pressure furnace 2 is moved (that is, the high temperature portion is relatively moved), and the above reactions are sequentially advanced in the boat 4 to synthesize a III-V compound semiconductor polycrystal.
[0024]
According to the synthesizing method according to this embodiment, the strip-shaped notches 52 that are wider than the slits 51 and extend from the cylinder wall open edge and are connected to the ends of the slits 51 are respectively provided on the both open end side cylinder wall surfaces of the boat body 50. And a circular heat-resistant film body 70 having a diameter slightly larger than the inner diameter of the boat body 50 and provided with a protruding piece 71 fitted to the strip-shaped notch 52 at a part of the outer peripheral edge thereof. Since the lid member 60 is screwed to both open ends of the boat main body 50 with the gap interposed therebetween, the screw portion of the lid member 60 and the screw portion of the boat main body 50 are chipped or loosened. Even if there are gaps in these screwed parts, the group III raw material 3 filled in the boat 4 by the action of the heat-resistant film body 70 interposed between the lid member 60 and the open end of the boat body 50 can be obtained. Leak into the above screwed part Furthermore, even when the group III raw material 3 remains in an unreacted state in the vicinity of the lid member 60, the III-V group compound semiconductor polycrystal synthesized by the action of the heat-resistant film body 70, the lid member 60, Will not adhere.
[0025]
Therefore, when the lid 60 is removed from the boat body 50 when the synthesis of the compound semiconductor polycrystal is finished, the lid 60 is not easily detached unlike the conventional case, and the reuse of the boat 4 is hindered. It has the advantage that there is no such thing.
[0026]
It should be noted that the width of the strip-shaped notch 52 provided on both open end side cylindrical wall surfaces of the boat body 50 may be the same width or narrow as the slit 51, and the strip-shaped notch 52 is at the end of the slit 51. It is not always necessary to be connected.
[0027]
Moreover, as a material of the said heat resistant film body 70, a carbon film, a pyrolytic boron nitride (p-BN) film, etc. are mentioned, for example. Further, the diameter of the heat-resistant film body 70 is only required to be slightly larger than the inner diameter of the boat main body 50, and the heat-resistant film body 70 is interposed in the boat 4 by interposing the heat-resistant film body 70 between the lid member 60 and the open end of the boat main body 50. Any dimension may be used as long as the filled group III raw material 3 does not leak into the screwed portion. Note that the shape of the heat-resistant film body 70 is not limited to a circular shape as long as leakage of the group III raw material 3 filled in the boat 4 to the screwed portion is prevented. For example, the boat body is opened. It may be a polygonal shape such as a regular octagon slightly larger than the surface. Further, with respect to the width dimension of the protrusion piece 71 provided on the outer peripheral edge of the heat resistant film body 70, if the protrusion piece 71 is fitted in the band-shaped notch portion 52 of the boat body 50 and is held in the boat 4. These dimensions are often arbitrary.
[0028]
【Example】
Examples of the present invention will be specifically described below.
[0029]
First, the graphite boat main body 50 having a diameter of 42 mm and a thickness of 0.4 mm, which is slightly larger than the inner diameter of the graphite boat main body 50 shown in FIG. The cover boat 60 was screwed to both open ends, and the synthesis boat 4 was assembled.
[0030]
As shown in FIG. 2, this boat 4 has dimensions of an outer diameter of 48 mm, an inner diameter of 40 mm, and a length of 745 mm. Inside this, gallium (Ga) 2000 g which is a group III raw material 3 is divided into two equal parts. Filled.
[0031]
Next, the graphite boat 4 filled with the group III raw material 3 is accommodated in the quartz inner tube 5 and arranged on one end side in the quartz sealed tube 1 for each quartz inner tube 5 as shown in FIG. On the other end side of the sealed tube 1, 920 g of red phosphorus (P) which is a group V raw material 6 was disposed. In the quartz sealed tube 1, a heat shielding plate 7 made of opaque quartz to which an introduction tube 10 for introducing the source gas of the group V material 6 into the quartz inner tube 5 is attached.
[0032]
Next, the quartz sealed tube 1 containing the quartz inner tube 5, the heat shielding plate 7, the group V raw material 6 and the like is closed, the inside is evacuated to the order of 10 ⁻⁶ Torr, and then sealed.
[0033]
Next, the quartz sealed tube sealed in a horizontal high pressure furnace 2 constituted by a high pressure vessel having a high frequency coil 8 in the center and sandwiching the high frequency coil 8 in the center and having resistance heaters 9 on both sides thereof. 1 is loaded, nitrogen gas is charged into the high-pressure vessel of the horizontal high-pressure furnace 2 and the inside of the high-pressure furnace is set to a high pressure state (40 kg / cm ² ), and then the resistance heater 9 is operated to heat the entire quartz sealed tube 1. Then, the temperature of the red phosphorus (P) which is the group V raw material 6 is increased to 300 ° C. to 700 ° C., and the gallium (Ga) which is the group III raw material 3 in the boat 4 is held in the range of 500 ° C. to 600 ° C. At the same time, the inside of the boat 4 is maintained at a temperature in the vicinity of 1470 ° C., which is the melting point of GaP, by operating the high frequency coil 8.
[0034]
Then, the raw material gas from the group V raw material 6 introduced into the quartz inner tube 5 through the introduction tube 10 attached to the heat shielding plate 7 and the group III raw material 3 in the boat 4 are reacted, and The quartz sealed tube 1 is moved in the horizontal high pressure furnace 2 in the direction of the arrow α (that is, the high temperature portion is relatively moved), and the above reactions are sequentially advanced in the boat 4 to integrate the III-V group compound semiconductor. (GaP) polycrystals were synthesized.
[0035]
On the other hand, as a comparative example, a conventional boat without a carbon film heat-resistant film body 70 interposed therebetween was also assembled, and a III-V compound semiconductor (GaP) polycrystal was synthesized under the same synthesis conditions as in the examples.
[0036]
And the synthesis | combination of the III-V compound semiconductor (GaP) polycrystal which concerns on an Example and a comparative example is performed repeatedly, the leakage state of the gallium (Ga) which is a III group raw material, the synthesized polycrystal, and the cover material 60 The adhesion state and the reuse life (durability) of the graphite boat 4 were compared. The results are shown in Table 1 below.
[0037]
In Table 1, “Raw material leakage occurrence rate (%)” is the ratio of the number of raw material leakages to the number of repeated synthesis, and “Adhesion rate with lid (%)” is the number of the above synthesis. It is the ratio of the number of the synthesized III-V compound semiconductor (GaP) polycrystal and the lid member 60 adhered. “The failure rate of graphite boat (%)” is the ratio of the number of boats damaged when taking out the synthesized III-V compound semiconductor (GaP) polycrystal with respect to the number of synthesis, “average number of use (times)” "Is the average number of times of repeated use for synthesis for one graphite boat.
[0038]
[Table 1]

As is apparent from the numerical values shown in Table 1, in the examples, leakage of gallium (Ga), which is a group III raw material, and adhesion between the synthesized III-V compound semiconductor (GaP) polycrystal and the lid member 60 It is confirmed that the occurrence rate of adhesion is greatly reduced.
[0039]
Further, the failure rate of the graphite boat in the example is 0.7%, which is greatly reduced from 18.2% in the comparative example, and the average number of times of use of the graphite boat in the example is 6.5 times. It is confirmed that it is remarkably improved compared to 2.4 times.
[0040]
【The invention's effect】
According to the method for synthesizing a compound semiconductor polycrystal according to the inventions of claims 1 and 2,
A strip-shaped notch extending from the open edge to the slit end direction is provided on both open end-side cylindrical wall surfaces of the boat body, and the strip-shaped notch is slightly larger than the open surface of the boat body and part of the outer periphery. The boat is configured by screwing lid members to both open ends of the boat body with a circular or polygonal heat-resistant film body provided with projection pieces fitted to the boat interposed therebetween. Therefore, even if the screw part of the lid member or the screw part of the boat main body is chipped or loosened, and there is a gap between these screwed parts, the above heat resistance interposed between the cover member and the open end of the boat main body The group III raw material filled in the boat by the action of the conductive film body does not leak to the screwing site, and even when the group III raw material remains in an unreacted state in the vicinity of the lid member, the heat resistance Due to the action of the film body Is a Group III-V compound semiconductor polycrystalline and the lid member has no sometimes resulting in adhesion.
[0041]
Therefore, when the synthesis of the compound semiconductor polycrystal is completed, the lid can be easily removed from the boat body, so that the boat can be prevented from being chipped or damaged, thereby greatly improving the reuse life of the boat. Has the effect of achieving.
[Brief description of the drawings]
FIG. 1 is a partially exploded perspective view of a boat applied to a method for synthesizing a compound semiconductor polycrystal according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing a method for synthesizing a III-V compound semiconductor polycrystal.
FIG. 3 is a schematic perspective view of a boat applied to a conventional method for synthesizing a group III-V compound semiconductor polycrystal.
FIG. 4 is a partially exploded perspective view of a boat applied to a method for synthesizing a III-V compound semiconductor polycrystal according to a conventional example.
[Explanation of symbols]
4 Boat 50 Boat body 51 Slit 52 Strip-shaped notch 60 Lid material 70 Heat-resistant film body 71 Projection piece

Claims

Group III raw material is filled into a boat which is composed of a cylindrical boat body with straight slits in the upper longitudinal direction and a lid member screwed to both open ends of the boat body. The boat is arranged on one end side in the sealed tube, while the V group material is arranged on the other end side in the sealed tube, the entire sealed tube is heated, and the group III material in the boat is locally heated to a higher temperature. A method for synthesizing a compound semiconductor polycrystal by reacting a source gas generated from a group V source by heating with the group III source and synthesizing a group III-V compound semiconductor polycrystal while gradually moving the high temperature part relatively In
A strip-shaped notch extending from the open edge to the slit end direction is provided on both open end-side cylindrical wall surfaces of the boat body, and the strip-shaped notch is slightly larger than the open surface of the boat body and part of the outer periphery. The boat is configured by screwing lid members to both open ends of the boat body with a circular or polygonal heat-resistant film body provided with projection pieces fitted to the boat interposed therebetween. A method of synthesizing a compound semiconductor polycrystal.

2. The method for synthesizing a compound semiconductor polycrystal according to claim 1, wherein the boat body and the lid are made of graphite, and the heat-resistant film is made of a carbon film.