JPS58100430A - Plasma processor - Google Patents

Abstract

PURPOSE:To reduce an adverse influence to be affected on a sample, and to attain the plasma process of high precision by a method wherein mesh type, ring type or bar type electrodes of the plural number are provided between parallel plane electrodes to constitute the device as to enable to perform formation of high precision of a minute pattern of various metal films, etc. CONSTITUTION:Etching gas 2B is introduced into a reaction vessel 1B as to hold the prescribed pressure, and gas is exhausted using an exhaust system 3B. The mesh electrodes 9, 10 of two pieces are provided between the upper electrode 4B connected to a high-frequency electric power source 6 and the earth electrode 5B, the mesh electrode 9 is connected to the high-frequency electric power source 6B, and plasma discharge 8B is formed in a gap between the parallel plane electrode 4B on the other side. Moreover the mesh electrode 10 is connected to a DC electric power source 13 through a high- frequency filter 11 and an ammeter 12, and the sample 7B is mounted on the parallel plane electrode 5B. Plasma generated by this constitution exists locally between the parallel plane electrode 4B and the mesh electrode 9, and the sample 7B is not exposed directly to plasma. Moreover a negative bias voltage is applied to the mesh electrode 10, and the number of electrons in plasma 8B to reach the sample 7B on the electrode 5B permeating the mesh electrode 10 is reduced.

Description

【発明の詳細な説明】 本発明は高周波放電により発生せしめたプラズマを利用
した処理装置に関し、主として半導体基板をプラズマに
よりエツチングまたはデボジシ諧ン処理するための処理
装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a processing apparatus using plasma generated by high-frequency discharge, and mainly relates to a processing apparatus for etching or depositing a semiconductor substrate using plasma.

従来の高周波放電を用いたプラズマ処理装置を第１図を
用いて説明する。図は、高周波放電を用いたプラズマに
よるエツチング装置の構成図である。反応容器ＩＡに、
エツチングガス２人を導入し、ガス排気装置３Ａにて反
応容器ＩＡの内圧力な一定圧に保ちながら排気する。４
人及び５Ａは　　　□平行平板電極で、一方の電極５人
上には試料７人が載荷される。他方の電極４人は高周波
電波６Ａｋ連結されており、前記電極５人は接地されて
いる。電極４人と５人間には高周波放電によりプラズマ
８人が形成される。A conventional plasma processing apparatus using high frequency discharge will be explained with reference to FIG. The figure is a configuration diagram of a plasma etching apparatus using high-frequency discharge. In reaction vessel IA,
Two etching gases are introduced and exhausted using a gas exhaust device 3A while maintaining the internal pressure of the reaction vessel IA at a constant pressure. 4
Person and 5A are □parallel plate electrodes, and 7 samples are loaded on 5 persons on one electrode. The other four electrodes are connected to high frequency radio waves 6Ak, and the five electrodes are grounded. Eight plasmas are formed between the four electrodes and the five people by high-frequency discharge.

例えば、被エツチ基板がポリシリコン膜の場合、エッチ
ガスはＣＦ４と０會との混合ガスであり、高周波は数Ｍ
〜数十ＭＨｚが用いられる。For example, when the substrate to be etched is a polysilicon film, the etching gas is a mixed gas of CF4 and 0.
~ several tens of MHz is used.

従来の他の技術例えば、シリ；ン窒化膜デポジシ璽ン処
理の場合には、反応ガスとしてはＳｉＨ４゜Ｎ、又はＮ
Ｈ，が用いられ、基板は図示せざる加熱手段により３０
０°〜４００ｒｌｉ度に加熱されて、基板上にシリコン
窒化膜（Ｓｔ、Ｎ、）がデボジシ冒ンされる。In other conventional techniques, for example, in the case of silicon nitride film deposition processing, the reaction gas is SiH4°N or N.
H, was used, and the substrate was heated to 30°C by heating means (not shown).
A silicon nitride film (St, N,) is deposited on the substrate by heating to 0° to 400°.

ところで、上述したように現在使用され【いるプラズマ
処理装置においては、試料は平行平板電極の一方の電極
上に載荷され、両電極間で放電により形成されたプラズ
マに直接さらされている。By the way, as mentioned above, in the currently used plasma processing apparatus, the sample is loaded on one of the parallel plate electrodes and is directly exposed to the plasma formed by discharge between the two electrodes.

そして、形成されたプラズマ中には、反応ガスの分解に
より生成された分子、原子、ラジカルやイオン、電子の
荷電粒子等が存在する。In the formed plasma, charged particles such as molecules, atoms, radicals, ions, and electrons generated by decomposition of the reactive gas are present.

このため％に電子は、平行平板電極間に印加された高周
波電界（数Ｍ〜数十ＭＨｚ　）に追随して加速され、試
料に衝突することによって試料の温度上昇、エツチング
のマスクに用いるホトレジスト膜への悪影響、試料基板
の電気特性への悪影響等の作用を及ぼす。しかしながら
、半導体集積回路の微細パターン形成のためには、試料
温度の上昇、ホトレジスト膜の変形は極力避けなければ
ならない。For this reason, electrons are accelerated by following the high frequency electric field (several megahertz to tens of megahertz) applied between the parallel plate electrodes, and when they collide with the sample, the temperature of the sample increases and the photoresist film used as an etching mask increases. and the electrical characteristics of the sample substrate. However, in order to form fine patterns for semiconductor integrated circuits, it is necessary to avoid increases in sample temperature and deformation of photoresist films as much as possible.

そこで、本発明の目的は、平行平板電極間に、複数個の
メッシ凰状、リング状又は棒状の電極な設置すると共に
該電極に交流又は直流の電位を印加して、プラズマ電位
を制御し、プラズマ放電領域を試料から隔離してポリシ
リコン膜、シリコン窒化膜、各種金属膜等の微細パター
ンの精度の高い形成や各種膜のデボジシｌンを行ない得
るように構成するととくより、高周波放電により形成さ
れたプラスＹＶｃより試料が受ける悪影響を低減し、高
精度のプラズマ処理を得るための装置を提供することＫ
ある。Therefore, an object of the present invention is to control the plasma potential by installing a plurality of mesh-shaped, ring-shaped, or rod-shaped electrodes between parallel plate electrodes, and applying an alternating current or direct current potential to the electrodes. In particular, the configuration is such that the plasma discharge region is isolated from the sample to enable highly accurate formation of fine patterns such as polysilicon films, silicon nitride films, various metal films, etc., and the deposition of various films. To provide an apparatus for reducing the adverse effects on a sample from positive YVc and obtaining high-precision plasma processing.
be.

以下、本発明を図示の実施例により説明する。Hereinafter, the present invention will be explained with reference to illustrated embodiments.

第２図は、本発明を薄膜の微細パターンエツチング用の
プラズマエツチング処理として適用した実施例を示した
ものである。このプラズマエツチング処理装置は、反応
容器ＩＢＫ一定Ｋ−なるよ５エツチガス２Ｂが導入され
、排気装置３Ｂを用いてガス排気される。高周波電源６
８に接続された上部電極４Ｂと接地電極５Ｂの関には、
２本のメッシλ１ｌＩＥ極９及び１０が設置され、メツ
シュ電極９は高電波電源６８に接続され、一方の平行平
板電極４Ｂとの間でプラズマ放電８Ｂが形成される。又
他のメツシー電極１ｏは、高周波フィルター１１．電流
計１２を介して直流電源１３ＶＣ接続される。試料７Ｂ
は平行平板電極５Ｂ上に載荷される。FIG. 2 shows an embodiment in which the present invention is applied as a plasma etching process for fine pattern etching of a thin film. In this plasma etching processing apparatus, an etching gas 2B is introduced into a reaction vessel IBK to a constant K-5, and the gas is exhausted using an exhaust device 3B. High frequency power supply 6
Between the upper electrode 4B and the ground electrode 5B connected to 8,
Two mesh λ11 IE electrodes 9 and 10 are installed, the mesh electrode 9 is connected to a high radio wave power source 68, and a plasma discharge 8B is formed between it and one parallel plate electrode 4B. Further, the other mesh electrode 1o has a high frequency filter 11. A DC power supply 13VC is connected via an ammeter 12. Sample 7B
is loaded on the parallel plate electrode 5B.

この構成によれば発生されるプラズマは平行平板電極４
Ｂとメック２電極９との関に局在しており、試料７Ｂは
直接プラズマにさらされることはない。又メツシー電極
１０には負のバイアスが印加される。それゆえプラズマ
８Ｂ中の電子がメツシー電極１０を透過して、電極５Ｂ
上の試料７ＢＫ到達する数は、第１図で示した従来装置
よりも少なくなる。According to this configuration, the plasma generated is generated by the parallel plate electrode 4.
The sample 7B is localized at the junction between the sample 7B and the MEC 2 electrode 9, and the sample 7B is not directly exposed to the plasma. Further, a negative bias is applied to the mesh electrode 10. Therefore, the electrons in the plasma 8B pass through the mesh electrode 10 and the electrode 5B
The number of samples 7BK above reaches is smaller than in the conventional apparatus shown in FIG.

上述したように、本発明によるプラズマ処理装置ではプ
ラズマが局在して形成され、直接試料に接触しないので
、プラズマ中の各種原子１分子。As mentioned above, in the plasma processing apparatus according to the present invention, plasma is formed locally and does not come into direct contact with the sample, so that each molecule of each type of atom in the plasma.

ラジカル及びイオンや原子の荷電粒子の影響を受けるの
が少なくなる。又試料載荷電極をプラズマとの関に設置
されたメツシュ状電極に負の電位を印加し【負のイオン
や電子の試料への到達を少なくすることｋより、試料温
度上昇、これによるホトレジスト膜の形状劣化、試料基
板の電気特性劣化等の′悪影響を少なくすることができ
る。It is less affected by radicals and charged particles such as ions and atoms. In addition, a negative potential is applied to a mesh-like electrode placed between the sample-loaded electrode and the plasma to reduce the amount of negative ions and electrons reaching the sample. Negative effects such as shape deterioration and electrical property deterioration of the sample substrate can be reduced.

なお、上述した実施例では、２枚のメツシュ状電極のう
ち、試料を載荷した電極に隣接したメツシュ電極には負
の直流を印加したが、電子の透過を少なくする目的から
、直流のかわりに、正弦波。In the above-mentioned example, a negative direct current was applied to the mesh electrode adjacent to the electrode loaded with the sample among the two mesh electrodes, but for the purpose of reducing the transmission of electrons, a negative direct current was applied instead of the direct current. ,sine wave.

矩形波、あるいは三角波等の交流電力を印加してもその
効果を得ることができる。This effect can also be obtained by applying alternating current power such as a rectangular wave or a triangular wave.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来用いられているプラズマ処理装置の概略図
、第２図は本発明による改良されたプラズマ処理装置の
概略図である。 １Ｂ・・・反応容器、２Ｂ・・・エッチガス、３Ｂ・・
・排気装置、４Ｂ、５Ｂ・・・平行平板電極、６Ｂ・・
・高周波電源、７Ｂ・・・試料、８Ｂ・・・プラズマ、
９．１０・・・メツシー電極、１１・・・フィルタ、１
２・・・電流針、１３・・・直流電源。FIG. 1 is a schematic diagram of a conventionally used plasma processing apparatus, and FIG. 2 is a schematic diagram of an improved plasma processing apparatus according to the present invention. 1B...Reaction container, 2B...Etch gas, 3B...
・Exhaust device, 4B, 5B...Parallel plate electrode, 6B...
・High frequency power supply, 7B...sample, 8B...plasma,
9.10...Metsy electrode, 11...Filter, 1
2... Current needle, 13... DC power supply.

Claims (1)

【特許請求の範囲】[Claims] １．２枚の平行平板電極間に高周波電力を印加してプラ
ズマを発生せしめる一方、鍍電極の一方に試料を載荷し
て試料のエツチングまたはデポジシ、ン処壜するプラズ
マ処理装置において、前記電極間に複数個のメッシ島状
、リング状または棒状の電極を設置すると共にこれら電
極に正弦波、矩屡波等の交流、または直流の電圧を印加
してグッズマ電位を制御し得るよう構成したことを特徴
とするプラズマ処ＩＩ装置。 Ｌ　４１許請求の範囲１１１ＥＩ項記載のプラズマ処理
装置において、試料載荷電極に対向する電極と、この電
極に最も接近したメッシ島状電極間に高周波電力を印加
してプラズマ放電をせしめ、前記試料載荷電極に接近し
た方のメッシ為電極には交流又は直流の電位あるいは負
の直流電圧を付加することを特徴とするプラズマ処理装
置。1. In a plasma processing apparatus in which high-frequency power is applied between two parallel plate electrodes to generate plasma, and a sample is loaded on one of the plate electrodes and the sample is etched or deposited, the gap between the electrodes is A plurality of mesh island-shaped, ring-shaped, or rod-shaped electrodes are installed in the electrode, and a voltage of alternating current (sine wave, square wave, etc.) or direct current is applied to these electrodes to control the Goodsma potential. Characteristic plasma treatment II equipment. L 41 In the plasma processing apparatus according to claim 111EI, high-frequency power is applied between the electrode facing the sample-loaded electrode and the mesh island-shaped electrode closest to this electrode to cause plasma discharge, and the sample-loaded A plasma processing apparatus characterized in that an alternating current or direct current potential or a negative direct current voltage is applied to the mesh electrode closer to the electrode.