JPH042124A - Dry etching - Google Patents
Dry etchingInfo
- Publication number
- JPH042124A JPH042124A JP10354190A JP10354190A JPH042124A JP H042124 A JPH042124 A JP H042124A JP 10354190 A JP10354190 A JP 10354190A JP 10354190 A JP10354190 A JP 10354190A JP H042124 A JPH042124 A JP H042124A
- Authority
- JP
- Japan
- Prior art keywords
- etching
- gas
- partial pressure
- compound semiconductor
- particles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001312 dry etching Methods 0.000 title claims description 14
- 238000005530 etching Methods 0.000 claims abstract description 54
- 239000007789 gas Substances 0.000 claims abstract description 40
- 239000004065 semiconductor Substances 0.000 claims abstract description 23
- 239000002245 particle Substances 0.000 claims abstract description 19
- 150000001875 compounds Chemical class 0.000 claims abstract description 18
- 239000011261 inert gas Substances 0.000 claims abstract description 13
- 230000005281 excited state Effects 0.000 claims abstract description 11
- 230000009257 reactivity Effects 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 22
- 150000002500 ions Chemical class 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000010884 ion-beam technique Methods 0.000 abstract description 5
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 17
- 239000000758 substrate Substances 0.000 description 14
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 10
- 238000010586 diagram Methods 0.000 description 7
- 239000000460 chlorine Substances 0.000 description 4
- 238000000605 extraction Methods 0.000 description 4
- 238000004544 sputter deposition Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 238000003776 cleavage reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 238000001020 plasma etching Methods 0.000 description 2
- 230000007017 scission Effects 0.000 description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- 229910000661 Mercury cadmium telluride Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Drying Of Semiconductors (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、化合物半導体をエツチングするドライエツチ
ング方法に係わり、特に反応性イオンビームエツチング
（ＲＩ Ｂ Ｅ）によるドライエツチング方法に関する
。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a dry etching method for etching compound semiconductors, and particularly to a dry etching method using reactive ion beam etching (RIBE). .
（従来の技術）
近年、シリコン以外の■−ｖ族化合物半導体やＩｆ−Ｖ
ｌ族化合物半導体は、半導体レーザ、発光ダイオード及
び受光器等の光デバイスに用いられ、また移動度の大き
いことを利用して電界効果トランジスタ、ヘテロバイポ
ーラトランジスタ等の電子デバイスに用いられている。(Prior art) In recent years, ■-v group compound semiconductors other than silicon and If-V
BACKGROUND ART Group I compound semiconductors are used in optical devices such as semiconductor lasers, light emitting diodes, and light receivers, and because of their high mobility, they are used in electronic devices such as field effect transistors and heterobipolar transistors.
これらのデバイスにおいて、任意のところに微細な構造
を作るための技術として、ドライエツチング方法が使用
されている。In these devices, a dry etching method is used as a technique for creating fine structures at arbitrary locations.
具体的には、半導体レーザを集積化するためのレーザ端
面形成、同一基板上に作られた２つ以上の素子を電気的
に分離するための分離溝形成、微細なゲートの作成等で
ある。このためには、加工面及び端面が平坦で、端面形
状が制御されていることが必要である。特に、レーザ端
面は活性層からの発光の取出し口に当たるため、端面反
射率の低下による光の損失を防ぐために、へき開面と同
等な平坦性、垂直性が要求される。Specifically, these include the formation of laser end faces for integrating semiconductor lasers, the formation of isolation grooves for electrically isolating two or more elements fabricated on the same substrate, and the creation of fine gates. For this purpose, it is necessary that the machined surface and end face be flat, and that the shape of the end face be controlled. In particular, since the laser end face corresponds to the extraction port for the light emitted from the active layer, it is required to have the same flatness and perpendicularity as the cleavage plane in order to prevent light loss due to a decrease in the end face reflectance.
従来、このようなドライエツチング方法として、反応性
イオンエツチング（ＲＩ Ｅ）や反応性イオンビームエ
ツチング（ＲＩ Ｂ Ｅ）等が主に用いられてきた。Ｒ
ＩＥでは、低真空度でのエツチングであるため、イオン
ビームの垂直性が良くないのを反映して加工面の垂直性
は十分ではなかった。そこで、比較的高真空度でエツチ
ングできるＲＩＢＥが垂直加工に用いられるようになっ
ている。Conventionally, reactive ion etching (RIE), reactive ion beam etching (RIBE), etc. have been mainly used as such dry etching methods. R
In IE, since etching is performed in a low vacuum, the perpendicularity of the processed surface was not sufficient, reflecting the poor perpendicularity of the ion beam. Therefore, RIBE, which can perform etching at a relatively high degree of vacuum, has come to be used for vertical processing.
しかしながら、ＲＩＢＥによるドライエツチング方法に
あっては次のような問題があった。However, the dry etching method using RIBE has the following problems.
即ち、ＲＩＢＥでは、エツチングに寄与する要素として
反応性粒子と基板との化学反応と、イオンによる物理的
なスパッタリングとの２つがあり、前者が加工面の平坦
性を、後者が加工面の垂直性を決めているが、それぞれ
トレードオフの関係にある。従って、平坦性と垂直性の
両方の特性を十分に満足させることはできなかった。具
体的には、比較的高真空のＲＩＢＥでは、加工表面を平
坦にするには反応性ガスの分圧を十分に高くしなければ
ならず、この場合は垂直性を損なうことになる。In other words, in RIBE, there are two factors that contribute to etching: a chemical reaction between reactive particles and the substrate, and physical sputtering by ions.The former affects the flatness of the processed surface, and the latter affects the perpendicularity of the processed surface. However, each has a trade-off relationship. Therefore, it was not possible to fully satisfy both flatness and verticality characteristics. Specifically, in RIBE at a relatively high vacuum, the partial pressure of the reactive gas must be sufficiently high in order to flatten the processed surface, and in this case, verticality will be impaired.
なお、基板面と反応性のビームの方向とのなす角度を垂
直から故意にずらして本来なら垂直でない加工面を基板
面に垂直にする方法もあるが、この場合はもう一方の面
が基板面と垂直とはならず、デバイスに応用する際には
制限を受ける。There is also a method of intentionally shifting the angle between the substrate surface and the direction of the reactive beam from perpendicular to make the processed surface, which is not normally perpendicular, perpendicular to the substrate surface, but in this case, the other surface is It is not perpendicular to the surface, and there are restrictions when applying it to devices.
（発明が解決しようとする課題）
このように従来、ＲＩＢＥで化合物半導体をエツチング
する場合、任意の面に垂直で、且つ平坦な加工面及び加
工端面のエツチングを行うことは困難であった。(Problems to be Solved by the Invention) Conventionally, when etching a compound semiconductor by RIBE, it has been difficult to etch a processed surface and a processed end surface that are perpendicular to any plane and are flat.
本発明は、上記事情を考慮し・てなされたもので、その
目的とするところは、化合物半導体に対し任意の面に垂
直で、且つ平坦な加工面及び加工端面のエツチングを行
うことのできるドライエツチング方法を提供することに
ある。The present invention has been made in consideration of the above circumstances, and its purpose is to provide a dry etching method that is perpendicular to any plane of a compound semiconductor and is capable of etching flat processed surfaces and processed end surfaces. The object of the present invention is to provide an etching method.
［発明の構成］
（課題を解決するための手段）
上記目的を達成するために本発明では、プラズマ室に導
入されたガスを励起してイオン化した粒子及び反応性の
高い励起状態の粒子を生成し、これらのイオン及び励起
状態の粒子を試料室に引き出し、イオンによる物理反応
と励起状態の粒子による化学反応を同時に起こさせ、試
料室内に配置された化合物半導体からなる試料をエツチ
ングするドライエツチング方法において、前記ガスとし
て反応性ガスと不活性ガスとの混合ガスを用いたことを
特徴としている。[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention excites a gas introduced into a plasma chamber to generate ionized particles and particles in an excited state with high reactivity. A dry etching method in which these ions and particles in an excited state are extracted into a sample chamber, and a physical reaction by the ions and a chemical reaction by the particles in an excited state occur simultaneously, thereby etching a sample made of a compound semiconductor placed in the sample chamber. The method is characterized in that a mixed gas of a reactive gas and an inert gas is used as the gas.
また本発明は、上記方法において、反応性ガスとしてＣ
Ｉ２、不活性ガスとしてＡｒを用い、試料室におけるＡ
ｒの分圧を６ Ｘ １０−４Ｔｏｒｒ以上に設定し、試
料室におけるＣｌ２の分圧をエツチング速度が最大とな
る近傍に設定したことを特徴としている。Further, the present invention provides C as a reactive gas in the above method.
I2, using Ar as an inert gas, A in the sample chamber
It is characterized in that the partial pressure of r is set to 6 x 10-4 Torr or more, and the partial pressure of Cl2 in the sample chamber is set in the vicinity where the etching rate is maximum.
（作用）
本発明によれば、比較的高真空でエツチングを行うため
、イオンビームの垂直性も損なわれることなく、物理的
なスパッタリングと化学反応も同時に起きるために、加
工面或いは加工端面も平坦なものが得られる。さらに、
反応性ガスに不活性ガスを加えることにより、チャンバ
に付着した反応生成物をスパッタリングにより取去る効
果があり、プラズマ状態の安定化、さらにはエツチング
工程の再現性及び制御性の向上にも大きな寄与がある。(Function) According to the present invention, since etching is performed in a relatively high vacuum, the perpendicularity of the ion beam is not impaired, and physical sputtering and chemical reactions occur simultaneously, so the processed surface or processed end surface is also flat. You can get something. moreover,
Adding an inert gas to the reactive gas has the effect of removing reaction products adhering to the chamber by sputtering, which greatly contributes to stabilizing the plasma state and improving the reproducibility and controllability of the etching process. There is.
（実施例） 以下、本発明の詳細を図示の実施例によって説明する。(Example) Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.
第１図は本発明の一実施例方法に使用したドライエツチ
ング装置を示す概略構成図である。FIG. 1 is a schematic diagram showing a dry etching apparatus used in an embodiment of the present invention.
図中１０は試料室であり、この試料室１０内には試料台
１１に載置されて被処理基板（試料）１２が収容されて
いる。２０はプラズマ室であり、このプラズマ室２０に
はマイクロ波発生器２１からマイクロ波が導入されると
共に、ガス導入口２２から所定のガスが導入される。プ
ラズマ室２０の周囲には磁場発生器２１が設けられてお
り、またプラズマ室２０の試料室１０側には引き出し電
極２４が設けられている。In the figure, 10 is a sample chamber, and in this sample chamber 10, a substrate to be processed (sample) 12 placed on a sample stage 11 is accommodated. Reference numeral 20 denotes a plasma chamber, into which microwaves are introduced from a microwave generator 21 and a predetermined gas is introduced from a gas inlet 22. A magnetic field generator 21 is provided around the plasma chamber 20, and an extraction electrode 24 is provided on the sample chamber 10 side of the plasma chamber 20.
そして、プラズマ室２０内に導入されたガスがマイクロ
波及び磁場により励起され、プラズマ２５が生成される
。このプラズマ２５中のイオン化した粒子と反応性の高
い励起状態にある粒子が電極２４により引き出され、試
料室１０内に導入される。また、試料室１０内に導入さ
れた上記粒子は基板１２に衝突したのち、ガス排気口１
３から排気されるものとなっている。Then, the gas introduced into the plasma chamber 20 is excited by microwaves and a magnetic field, and plasma 25 is generated. Particles in an excited state that are highly reactive with the ionized particles in the plasma 25 are extracted by the electrode 24 and introduced into the sample chamber 10. Further, the particles introduced into the sample chamber 10 collide with the substrate 12 and then pass through the gas exhaust port 1.
It is designed to be exhausted from 3.
この装置の基本的な構成は従来のＥＣＲ型イオン源を用
いたＲＩＢＥ装置と同様であるが、この装置ではプラズ
マ室２０内に導入するガスとして、塩素（ＣＩ２）等の
反応性ガスのみではなく、これとアルゴン（Ａｒ）等の
不活性ガスとの混合ガスを用いることを特徴としている
。The basic configuration of this device is similar to a conventional RIBE device using an ECR type ion source, but in this device, not only reactive gases such as chlorine (CI2) are introduced into the plasma chamber 20. , is characterized by using a mixed gas of this and an inert gas such as argon (Ar).
第２図は本発明方法を利用した １ｎＧａＡｓＰレーザ
の垂直端面の形成工程を示す断面図である。まず、第２
図（ａ）に示すように、ｌｊ＃ｉ組成のＩ ｎＧａＡｓ
Ｐ活性層を持っメサ埋込み型の半導体レーザウェハ３
０上に電極プロセスにより電極３１を形成した後に、常
圧ＣＶＤ法で５ｉ０２膜３２を堆積し、さらにこの５ｉ
ｎ２膜３２をバターニングしてエツチング用の溝を開け
る。次いで、前記第１図に示す装置を用い、第２図（ｂ
）に示すように、５ｉｎ２膜３２をマスクとしてレーザ
ウェハ３０をエツチングして、レーザの垂直端面を形成
した。FIG. 2 is a cross-sectional view showing the process of forming a vertical end face of a 1nGaAsP laser using the method of the present invention. First, the second
As shown in Figure (a), InGaAs with lj#i composition
Mesa-embedded semiconductor laser wafer with P active layer 3
After forming an electrode 31 on 0 by an electrode process, a 5i02 film 32 is deposited by normal pressure CVD method, and then this 5i0
The N2 film 32 is buttered to open a groove for etching. Next, using the apparatus shown in FIG.
), the laser wafer 30 was etched using the 5in2 film 32 as a mask to form vertical end faces of the laser.
このとき、エツチングの条件としては、マイクロ波出力
２００Ｗ 、磁場強度８７５ガウスでプラズマ室２０に
導入されたＣｌ２ガスとＡｒガスとの混合ガスをプラズ
マ化し、引き出し電圧４００ｖで試料室１０にイオンと
励起状態の反応性粒子を導く。ここで、試料室１０内に
おけるＣｌ２分圧は７．５Ｘ １０−４ＴｏｒｒＳＡ
ｒ分圧は１６４Ｘ １０−４Ｔｏｒｒとした。得られた
イオン電流密度は０．２４ｍＶ／ ｃ＋ａ２であり、イ
オン照射により、基板１２の表面温度は常温から約２分
で１８０℃に上昇し、その後は安定であった。エツチン
グを２０分行って、エツチング溝３３の深さは５μｍで
あった。At this time, the etching conditions were as follows: A mixed gas of Cl2 gas and Ar gas introduced into the plasma chamber 20 was turned into plasma using a microwave output of 200 W and a magnetic field strength of 875 Gauss, and ions were excited in the sample chamber 10 with an extraction voltage of 400 V. Leading state reactive particles. Here, the Cl2 partial pressure in the sample chamber 10 is 7.5X 10-4 TorrSA
The r partial pressure was 164×10 −4 Torr. The obtained ion current density was 0.24 mV/c+a2, and the surface temperature of the substrate 12 rose from room temperature to 180° C. in about 2 minutes due to ion irradiation, and remained stable thereafter. Etching was performed for 20 minutes, and the depth of the etched groove 33 was 5 μm.
エツチングマスク３２をウェットエツチングで除去し電
極３１を露出させて得られた半導体レーザの特性は、へ
き開面のレーザと比べてしきい値は３０■Ａと同等であ
り、エツチングによるしきい値のばらつきも、レーザウ
ェハ３０の面内分布を反映していた。なお、第２図（ｅ
）にエツチングにより露出した端面形状を示す。The characteristics of the semiconductor laser obtained by removing the etching mask 32 by wet etching and exposing the electrode 31 are that the threshold value is equivalent to 30A compared to a cleavage plane laser, and the threshold value varies due to etching. Also reflected the in-plane distribution of the laser wafer 30. In addition, Fig. 2 (e
) shows the shape of the end face exposed by etching.
次に、化合物半導体をエツチングする際の最適条件、即
ち反応性ガスの分圧、不活性ガスの分圧及び基板温度等
の最適条件について説明する。ＩｎＧａＡｓＰ／ＩｎＰ
のへテロ接合を含む構造にドライエツチングを施すとき
に重要なことは、それぞれの材料についてのエツチング
特性が異なることである。Ｉ ｎＧａＡｓ ＰはＩｎＰ
とＧａＡｓをある割合で混合したものであると考え、Ｉ
ｎＰとＧａＡｓのエツチング特性を調べた。Next, the optimum conditions for etching a compound semiconductor, ie, the optimum conditions such as the partial pressure of the reactive gas, the partial pressure of the inert gas, and the substrate temperature will be explained. InGaAsP/InP
When performing dry etching on a structure containing a heterojunction, it is important to note that the etching characteristics of each material are different. InGaAs P is InP
Considering that it is a mixture of GaAs and GaAs in a certain proportion, I
The etching characteristics of nP and GaAs were investigated.
第３図及び第４図にＩｎＰ及びＧａＡｓについて、エツ
チング速度（第３図）、及びエツチング側壁面と基板面
とのなす角度（第４図）のＣｌ２圧力依存性について示
す。第３図及び第４図は、Ｃｌ２及びＡｒガスをプラズ
マ室に導入し、マイクロ波出力２００Ｗ 、磁場強度８
７５ガウスでイオン又は反応性の励起状態の粒子を作り
、４００Ｖで試料室に引き出す条件で、Ａｒガスの分圧
が１．４Ｘ １０−４Ｔｏｒｒのときのものである。FIGS. 3 and 4 show the Cl2 pressure dependence of the etching rate (FIG. 3) and the angle between the etched side wall surface and the substrate surface (FIG. 4) for InP and GaAs. In Figures 3 and 4, Cl2 and Ar gas are introduced into the plasma chamber, the microwave output is 200 W, and the magnetic field strength is 8.
The conditions are that ions or reactive excited state particles are created at 75 Gauss and extracted into the sample chamber at 400 V, and the partial pressure of Ar gas is 1.4×10 −4 Torr.
第４図からＩｎＰに関しては、側壁面と基板面とのなす
角度θは、Ｃｌ２ガスの分圧が７．５×１０−４Ｔｏｒ
ｒのときの９０度を境に、それ以上でもそれ以下でも９
０度より小さくなる。そして、この７．５Ｘ １０−４
Ｔｏｒｒの分圧は、第３図に示すようにエツチング速度
の極大にも対応している。From FIG. 4, for InP, the angle θ between the side wall surface and the substrate surface is such that the partial pressure of Cl2 gas is 7.5×10-4 Torr.
90 degrees at r
It becomes smaller than 0 degrees. And this 7.5X 10-4
The partial pressure of Torr also corresponds to the maximum etching rate, as shown in FIG.
このとき、ＧａＡｓのエツチング特性は、順メサ方向に
垂直な面と、逆メサに方向に垂直な面で異なり、それぞ
れ基板面と側壁とのなす角度は８５度、９５度であった
。実際には、活性層はＩｎＧａＡｓＰなので、特性は１
ｎＰに近くなり、１．’ａａｍｍ成のＩｎＧａＡｓＰで
は略９０度であった。また、ＩｎＰのエツチング速度が
極大となるところでは、ＧａＡｓとのエツチング速度と
の差が最も小さくなり、等速エツチングに近い状況とな
るため、ヘテロ接合付近での段差がなくなり、垂直形状
が実現できた。At this time, the etching characteristics of GaAs were different between a surface perpendicular to the forward mesa direction and a surface perpendicular to the reverse mesa direction, and the angles formed between the substrate surface and the sidewalls were 85 degrees and 95 degrees, respectively. Actually, since the active layer is InGaAsP, the characteristic is 1.
Close to nP, 1. In the case of 'aamm-formed InGaAsP, the angle was approximately 90 degrees. In addition, where the etching speed of InP is maximum, the difference between the etching speed of GaAs and GaAs is the smallest, resulting in a situation close to constant speed etching, which eliminates the step near the heterojunction and makes it possible to realize a vertical shape. Ta.
ＩｎＰの場合、プラズマの照射により基板表面の温度が
上昇するが、この温度は１５０℃以下だと不純物及び塩
化物の吸着のために、表面が平坦にならず、２００℃以
上だと横方向のエツチングが進み、垂直性が損なわれる
傾向にあった。In the case of InP, the temperature of the substrate surface increases due to plasma irradiation, but if this temperature is below 150°C, the surface will not be flat due to the adsorption of impurities and chlorides, and if it is above 200°C, the surface will not be flat. Etching progressed and verticality tended to be lost.
従って、ＩｎＰでは１５０〜２００℃で平坦な面が得ら
れることになる。ＧａＡｓの場合、エツチング時の基板
表面の温度は５０〜１５０℃、１．３μｍ組成のＩｎＧ
ａＡｓＰの場合は１００〜１Ｂ（１℃、１．５μｍのＩ
ｎＧａＡｓＰの場合は１３０〜１８０℃に保つと平坦な
面が得られ、サイドエツチングを防止することができた
。Therefore, with InP, a flat surface can be obtained at 150 to 200°C. In the case of GaAs, the temperature of the substrate surface during etching is 50 to 150°C, and InG with a composition of 1.3 μm
In the case of aAsP, the I
In the case of nGaAsP, a flat surface was obtained by keeping the temperature at 130 to 180°C, and side etching could be prevented.
ここまでの説明では不活性ガスとしてのＡｒの分圧を１
．４Ｘ １０−４Ｔｏｒｒに設定した場合、反応性ガス
としてのＣｌ０の分圧を７．５Ｘ １０−４Ｔｏｒｒ近
傍に設定することにより、平坦性の良い垂直なエツチン
グが実現されるのが確認された。しかし、Ａｒ添加量に
対して垂直、平坦面が得られるＣｌ２分圧は異なってい
る。第５図に、側壁とのなす角度が８５〜９５度に入る
Ｃｌ２分圧の範囲と側壁とのなす角度が９０度になるＣ
ｌ２分圧を示す。Ａｒ分圧が高くなると、それに対する
Ｃｌ２分圧は低くなる。また、Ａｒの分圧が低いと平坦
なエツチング面は得られないが、Ａｒ分圧が６ Ｘ １
０−４Ｔｏｒｒ以上で平坦なエツチング面が得られるこ
とが確認された。In the explanation so far, the partial pressure of Ar as an inert gas is 1
．． It was confirmed that vertical etching with good flatness could be achieved by setting the partial pressure of Cl0 as a reactive gas to around 7.5X 10-4 Torr when the etching was set at 4X 10-4 Torr. However, the Cl2 partial pressure at which a flat surface can be obtained perpendicular to the amount of Ar added is different. Figure 5 shows the range of Cl2 partial pressure where the angle with the side wall is 85 to 95 degrees and the range of C where the angle with the side wall is 90 degrees.
12 partial pressure is shown. As the Ar partial pressure increases, the corresponding Cl2 partial pressure decreases. Also, if the Ar partial pressure is low, a flat etched surface cannot be obtained, but if the Ar partial pressure is 6 x 1
It was confirmed that a flat etched surface could be obtained at 0-4 Torr or higher.
ここで特徴的なことは、Ａｒの分圧に対して側壁とのな
す角度が８５〜９５度に入るＣｌ□の分圧は、Ａｒの分
圧に対してエツチング速度が最大となるＣＩ。の分圧に
略等しいことである。What is characteristic here is that when the partial pressure of Cl□ forms an angle of 85 to 95 degrees with the side wall relative to the partial pressure of Ar, the etching rate is maximum relative to the partial pressure of Ar. This is approximately equal to the partial pressure of
即ち、Ａｒの分圧が変わると、第３図に示すＩｎＰのエ
ツチング速度曲線が左右にシフトし、その最大速度とな
るＣｌ．の分圧が、第５図に示す範囲内に入っているこ
とである。従って、垂直エツチングが可能で平坦なエツ
チング面が得られる条件は、Ａ「の分圧が６ Ｘ １０
−４Ｔｏｒｒ以上で、Ｃｌ２の分圧はエツチング速度が
最大となる近傍であることである。より望ましくは、こ
れに加え、エツチングする材料に応じて温度条件を先に
説明した範囲に設定すればよい。That is, when the partial pressure of Ar changes, the InP etching rate curve shown in FIG. 3 shifts left and right, and the maximum rate of Cl. The partial pressure of is within the range shown in FIG. Therefore, the conditions under which vertical etching is possible and a flat etched surface is obtained is that the partial pressure of A is 6 x 10
Above -4 Torr, the partial pressure of Cl2 is close to the maximum etching rate. More preferably, in addition to this, the temperature conditions may be set within the range described above depending on the material to be etched.
第６図は、Ｃｌ２ガスにＡ「を分圧で１．４×１０′−
３Ｔｏｒｒだけ添加したときと、Ａｒを全く加えなかっ
たときの、エツチング速度の実験間のばらつきを示す。Figure 6 shows A' in Cl2 gas at a partial pressure of 1.4 x 10'-
The experiment-to-experiment variation in etching rate is shown when only 3 Torr is added and when no Ar is added.
ＣＩ、分圧は７．５ｘ １０−４Ｔｏｒｒとした。Ａ「
を全く加えなかったときは、物理的なスパッタ効果が小
さいために、Ａｒを加えたときよりもエツチング速度が
小さくなっているが、そのばらつきが大きい。それに比
べ、Ａｒを加えたときはエツチング速度のばらつきが５
％以内に入っている。第７図はＣｌ２分圧を７．５Ｘ
１０−’Ｔｅｒｒに固定したとき、Ａｒガス添加量とエ
ツチング速度の実験間のばらつきを示すものである。Ａ
「ガスを６ Ｘ １０’−４Ｔｏｒｒ以上添加すると、
ばらつきを５％以内に抑えられることが分かる。CI and partial pressure were set to 7.5x 10-4 Torr. A"
When Ar is not added at all, the physical sputtering effect is small, so the etching rate is lower than when Ar is added, but the variation is large. In comparison, when Ar was added, the variation in etching speed was 5
It is within %. Figure 7 shows the Cl2 partial pressure at 7.5X.
It shows the variation between experiments in the amount of Ar gas added and the etching rate when fixed at 10-'Terr. A
"When adding gas at 6 x 10'-4 Torr or more,
It can be seen that the variation can be suppressed to within 5%.
このように本実施例方法によれば、ＩｎＰ／１ｎＧａＡ
ｓＰ等の化合物半導体をＲＩＢＥでエツチングする際に
、反応性ガスとしてのＣｌ２に不活性ガスとしてのＡｒ
を添加し、それぞれの分圧を最適化することにより、化
合物半導体に対し任意の面に垂直で、且つ平坦な加工面
及び加工端面のエツチングを行うことができる。As described above, according to the method of this embodiment, InP/1nGaA
When etching a compound semiconductor such as sP by RIBE, Cl2 as a reactive gas and Ar as an inert gas are used.
By adding and optimizing the respective partial pressures, etching can be performed perpendicular to any plane of the compound semiconductor and flat processed surfaces and processed end surfaces.
また、第６図及び第７図に示したように、Ａｒガスを添
加することにより、エツチングの再現性の向上をはかる
ことも可能であり、その有用性は絶大である。Further, as shown in FIGS. 6 and 7, it is possible to improve the reproducibility of etching by adding Ar gas, and this is extremely useful.
なお、本発明は上述した実施例に限定されるものではな
い。実施例では、ＥＣＲ型イオン源を用いたＲＩＢＥ装
置を用いたが、これに限らずプラズマ室でガスを励起し
てイオン化した粒子及び反応性の高い励起状態の粒子を
生成し、これらのイオン及び励起状態の粒子を試料室に
引き出す構成であればよい。また、反応性ガスとしては
ブロム、ヨウ素等を用いることができ、不活性ガスとし
て窒素、キセノン、ヘリウム等を用いることができる。Note that the present invention is not limited to the embodiments described above. In the example, a RIBE apparatus using an ECR type ion source was used, but the present invention is not limited to this, and the gas is excited in a plasma chamber to generate ionized particles and particles in an excited state with high reactivity, and these ions and Any configuration may be used as long as the particles in an excited state are drawn out into the sample chamber. Moreover, bromine, iodine, etc. can be used as a reactive gas, and nitrogen, xenon, helium, etc. can be used as an inert gas.
さらに、被エツチング材料としては ＧａＡ Ｉ＾ｓ／
ＧａＡｓ系、ＩｎＧａＡＩＰ／ＧａＡｓ系、更にはＺｎ
５ｅ、ＣｄＨｇＴｅ等のＩＩ−Ｖｌ族化合物半導体にも
適用することが可能である。その他、本発明の要旨を逸
脱しない範囲で、種々変形して実施することができる。Furthermore, the material to be etched is GaA I^s/
GaAs-based, InGaAIP/GaAs-based, and even Zn
It is also possible to apply the present invention to II-Vl group compound semiconductors such as 5e and CdHgTe. In addition, various modifications can be made without departing from the gist of the present invention.
［発明の効果］
以上詳述したように本発明によれば、ＲＩＢＨにより化
合物半導体をエツチングするに際し、Ｃｌ２等の反応性
ガスにＡｒ等の不活性ガスを添加した混合ガスを用いる
ことにより、化合物半導体に対し任意の面に垂直で、且
つ平坦な加工面及び加工端面のエツチングを行うことが
できる。[Effects of the Invention] As detailed above, according to the present invention, when etching a compound semiconductor by RIBH, by using a mixed gas in which an inert gas such as Ar is added to a reactive gas such as Cl2, the compound semiconductor can be etched by RIBH. Etching can be carried out perpendicular to any plane of the semiconductor and flat processed surfaces and processed end surfaces.
第１図は本発明の一実施例方法に使用したＥＣＲ放電利
用のドライエツチング装置を示す概略構成図、第２図は
上記装置を用いたレーザ端面形成工程を示す断面図、第
３図はＡｒ添加時のＣｌ２分圧とエツチング速度との関
係を示す特性図、第４図はＣｌ２分圧と側壁のなす角度
との関係を示す特性図、第５図はＡ「分圧に対して垂直
エツチングを実現する％Ｃｌ□Ｃｌ０変化を示す特性図
、第６図はＡｒの有無によるエツチング速度のバラツキ
を示す特性図、第７図はＡｒ分圧に対するエツチング速
度のバラツキを示す特性図である。
１０・・・試料室、
１１・・・試料台、
１２・・・被処理基板（試料）、
１３・・・ガス排気口、
２０・・・プラズマ室、
２１・・・マイクロ波発生器、
２２・・・ガス導入口、
２３・・・磁場発生器、
２４・・・引き出し電極、
２５・・・プラズマ、
３０・・・レーザウェハ、
３１・・・電極、
３２・・・５ｉｎ２マスク、
３３・・・エツチング溝。
第３図
出願人代理人 弁理士 鈴 江 武 彦第５
図
第６図
ランＮ。
第
図FIG. 1 is a schematic configuration diagram showing a dry etching device using ECR discharge used in a method according to an embodiment of the present invention, FIG. 2 is a sectional view showing a laser end face forming process using the above device, and FIG. 3 is an Ar A characteristic diagram showing the relationship between the Cl2 partial pressure and the etching rate during addition, Figure 4 is a characteristic diagram showing the relationship between the Cl2 partial pressure and the angle formed by the side wall, and Figure 5 is a characteristic diagram showing the relationship between the Cl2 partial pressure and the angle formed by the side wall. Fig. 6 is a characteristic diagram showing the variation in etching rate depending on the presence or absence of Ar, and Fig. 7 is a characteristic diagram showing the variation in etching rate with respect to Ar partial pressure. ...sample chamber, 11...sample stage, 12...substrate to be processed (sample), 13...gas exhaust port, 20...plasma chamber, 21...microwave generator, 22. ...Gas inlet, 23...Magnetic field generator, 24...Extraction electrode, 25...Plasma, 30...Laser wafer, 31...Electrode, 32...5in2 mask, 33... Etched groove. Figure 3: Applicant's representative Patent attorney Takehiko Suzue Figure 5 Figure 6 Run N. Figure
Claims (3)
スと不活性ガスとの混合ガスをプラズマ室に導入し、こ
のプラズマ室でガスを励起してイオン化した粒子及び反
応性の高い励起状態の粒子を生成し、これらのイオン及
び励起状態の粒子を試料室に引き出し、イオンによる物
理反応と励起状態の粒子による化学反応を同時に起こさ
せ、試料室内に配置された化合物半導体からなる試料を
エッチングすることを特徴とするドライエッチング方法
。(1) When etching a compound semiconductor, a mixed gas of a reactive gas and an inert gas is introduced into a plasma chamber, and the gas is excited in the plasma chamber to produce ionized particles and particles in an excited state with high reactivity. These ions and particles in an excited state are generated and drawn into a sample chamber, and a physical reaction by the ions and a chemical reaction by particles in an excited state occur simultaneously, thereby etching a sample made of a compound semiconductor placed in the sample chamber. Characteristic dry etching method.
としてＡｒを用いたことを特徴とする請求項１記載のド
ライエッチング方法。(2) The dry etching method according to claim 1, characterized in that Cl_2 is used as the reactive gas and Ar is used as the inert gas.
４Ｔｏｒｒ以上に設定し、前記試料室におけるＣｌ＿２
の分圧をエッチング速度が最大となる近傍に設定したこ
とを特徴とする請求項２記載のドライエッチング方法。(3) Set the partial pressure of Ar in the sample chamber to 6×10^-^
Cl_2 in the sample chamber was set at 4 Torr or higher.
3. The dry etching method according to claim 2, wherein the partial pressure of is set in the vicinity of a maximum etching rate.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10354190A JP3167310B2 (en) | 1990-04-19 | 1990-04-19 | Dry etching method |
| EP19910106251 EP0457049A3 (en) | 1990-04-19 | 1991-04-18 | Dry etching method |
| US07/687,569 US5304514A (en) | 1990-04-19 | 1991-04-19 | Dry etching method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10354190A JP3167310B2 (en) | 1990-04-19 | 1990-04-19 | Dry etching method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH042124A true JPH042124A (en) | 1992-01-07 |
| JP3167310B2 JP3167310B2 (en) | 2001-05-21 |
Family
ID=14356705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10354190A Expired - Fee Related JP3167310B2 (en) | 1990-04-19 | 1990-04-19 | Dry etching method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3167310B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011166059A (en) * | 2010-02-15 | 2011-08-25 | Nippon Telegr & Teleph Corp <Ntt> | Dry etching method |
-
1990
- 1990-04-19 JP JP10354190A patent/JP3167310B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011166059A (en) * | 2010-02-15 | 2011-08-25 | Nippon Telegr & Teleph Corp <Ntt> | Dry etching method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3167310B2 (en) | 2001-05-21 |
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