JPS6376329A - Etching method - Google Patents
Etching methodInfo
- Publication number
- JPS6376329A JPS6376329A JP21922386A JP21922386A JPS6376329A JP S6376329 A JPS6376329 A JP S6376329A JP 21922386 A JP21922386 A JP 21922386A JP 21922386 A JP21922386 A JP 21922386A JP S6376329 A JPS6376329 A JP S6376329A
- Authority
- JP
- Japan
- Prior art keywords
- trench
- chcl3
- etching
- chlorine
- mixture
- 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.)
- Pending
Links
- 238000005530 etching Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 13
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 17
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000000460 chlorine Substances 0.000 claims abstract description 12
- 229910052801 chlorine Inorganic materials 0.000 claims abstract description 12
- 239000004065 semiconductor Substances 0.000 claims abstract description 3
- 238000001020 plasma etching Methods 0.000 claims description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 15
- 229910052710 silicon Inorganic materials 0.000 abstract description 15
- 239000010703 silicon Substances 0.000 abstract description 15
- 239000000203 mixture Substances 0.000 abstract description 5
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 abstract 6
- 229910003910 SiCl4 Inorganic materials 0.000 abstract 1
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 14
- 229910052581 Si3N4 Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 210000003608 fece Anatomy 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 244000228957 Ferula foetida Species 0.000 description 1
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000013332 literature search Methods 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000005368 silicate glass Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000000992 sputter etching Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Landscapes
- Drying Of Semiconductors (AREA)
Abstract
Description
【発明の詳細な説明】
〔概要〕
塩素または塩素系のガスを用いるシリコン・トレンチ・
エツチングにおいて、前記ガスにクロロホルム(CH(
J!3)を加えることによってアンダカットの発生を防
止する。[Detailed description of the invention] [Summary] Silicon trench treatment using chlorine or chlorine-based gas
In etching, the gas is chloroform (CH(
J! 3) prevents the occurrence of undercuts.
本発明はエツチング方法に関するもので、さらに詳しく
言えば、塩素または塩素系ガスを用いるリアクティブ・
イオン・エッチング(Reactiveton Etc
hing+ RIE)によるシリコン基板の工・ノチン
グにおいて、従来みられたボトル形状のエツチングや埋
没層におけるアンダカットの発生を防止する方法に関す
るものである。The present invention relates to an etching method, and more specifically, a reactive etching method using chlorine or chlorine-based gas.
Ion etching
The present invention relates to a method for preventing bottle-shaped etching and undercutting in buried layers, which have conventionally been observed, in processing and notching silicon substrates by Hing+ RIE.
シリコン基板にトレンチ(溝)を形成するためのエツチ
ングは第3図に示される方法により、シリコン基板11
上に酸化膜(5i02膜)12と窒化シリコン膜13と
を順に形成し、その上に燐・シリケート・ガラス(PS
G ”) It!t!14を作り、PSG膜14に窓1
5を窓開けする。次いで塩素(C122)または塩素系
(Stα4+α2)ガスを使用するRIEによって基板
11にトレンチ(溝)16を形成する。Etching for forming a trench (groove) in the silicon substrate is carried out by the method shown in FIG.
An oxide film (5i02 film) 12 and a silicon nitride film 13 are formed in this order on top, and phosphorus silicate glass (PS) is formed on top of that.
G”) It!t!14 is made and window 1 is made on the PSG film 14.
Open window 5. Next, a trench 16 is formed in the substrate 11 by RIE using chlorine (C122) or chlorine-based (Stα4+α2) gas.
最初はC22のみを用いるエツチングを行っていたが、
基板11にn+型の埋没層17が形成されている場合に
は、埋没層17でアンダカソトが発生し、翼(ウィング
)状部分18もエツチングされることがS忍められた。Initially, etching was performed using only C22, but
When the n+ type buried layer 17 is formed on the substrate 11, undercutting occurs in the buried layer 17, and the wing-like portions 18 are also etched.
そこで、塩素ニ5iCet 、 BIJ 3 、
CCe4ナト’c加えた塩素系ガスによるエツチングが
試みられ、かかる塩素系ガスを用いて埋没層におけるア
ンダカット発生の問題は一応解決した。Therefore, chlorine 5iCet, BIJ 3,
Etching with a chlorine-based gas to which CCe4Nat was added was attempted, and the problem of undercutting in the buried layer was temporarily solved using such a chlorine-based gas.
しかし、かかるRIEにおいて、シリコン基板の上下方
向だけでなく横方向のエツチングも進行し、トレンチ1
6の断面形状が第4図に示される如(ボトル形状になる
ことが認められた。そうなると、f’sG膜14の窓1
5の窓開けを幅Wに設定したものの、Wより大なる幅W
“のトレンチが形成され、そのことは基板11に形成す
るデバイスの微細化の妨げとなる問題がある。However, in such RIE, etching progresses not only in the vertical direction of the silicon substrate but also in the lateral direction, and the etching progresses in the trench 1.
As shown in FIG.
Although the window opening in step 5 is set to width W, the width W is larger than W.
A trench of "" is formed, which poses a problem of hindering the miniaturization of devices formed on the substrate 11.
本発明はこのような点に鑑みて創作されたもので、シリ
コン基板のトレンチ・エツチングにおいて、トレンチが
ボトル状に横方向にふくらんだ形状で形成されたり、ま
たは埋没層におけるアンダカノトの発生を防止しうる方
法を提供することを目的とする。The present invention was created in view of the above points, and it is possible to prevent the trench from being formed in a bottle-like shape that bulges in the lateral direction, or to prevent the formation of undercuts in the buried layer in trench etching of a silicon substrate. The purpose is to provide a method for
第1図は本発明実施例断面図で、図中、21はリアクテ
ィブ・イオン・エッチング装置、22はシリコン基板1
1をのせるサセプタ、23は対向電極板、24は接地さ
れた高周波(RF)発振器、25はエツチング用のガス
導入管、26は排気系、27は冷却系である。FIG. 1 is a cross-sectional view of an embodiment of the present invention, in which 21 is a reactive ion etching device, 22 is a silicon substrate 1
23 is a counter electrode plate, 24 is a grounded radio frequency (RF) oscillator, 25 is a gas introduction pipe for etching, 26 is an exhaust system, and 27 is a cooling system.
本発明においては、装置21内でRF発振器からのRF
によってカソード23と基板11の間にプラズマ28(
図に砂地を付して示す)を発生させ、ガス導入管25か
らSt便4+ヴ2+CH便3を導入してl?IEでシリ
コン基板11をエツチングする。In the present invention, within the device 21, the RF
Plasma 28 (
(shown with a sandy area in the figure), and introduce St flight 4 + V 2 + CH flight 3 from the gas introduction pipe 25. Etch the silicon substrate 11 using IE.
上記した方法においては、第2図に示される如く、エツ
チングされつつあるトレンチ16の側壁16a上に前記
ガスによってCxHySiの堆積物19が被着され、こ
の堆積物が保護膜となってシリコン基板の横方向エツチ
ングや埋没層におけるアンダカソトの発生を防止する。In the above method, as shown in FIG. 2, a CxHySi deposit 19 is deposited by the gas on the side wall 16a of the trench 16 being etched, and this deposit serves as a protective film for the silicon substrate. Prevents lateral etching and undercutting in buried layers.
以下、図面を参照して本発明の実施例を詳細に説明する
。Embodiments of the present invention will be described in detail below with reference to the drawings.
本発明者は、鄭2にSt便4+ 8便3. Cα4
などを添加したガスを用いるシリコン基板のトレンチ・
エツチングで、埋没層におけるアンダカットは防止され
たもののボトル状形状にエツチングが進行することを確
認した後に、ボトル状エツチングを阻止するガスの有無
について文献調査をなしたが、そのようなガスの存在を
報告する文献を見出しえなかった。そこで、本発明者は
各種のガスを添加したエツチングについて実験し、クロ
ロホルム(CHCf! 3 )を添加した場合にトレン
チ16は上下方向に真直ぐにエツチングされることを確
認した。The inventor has provided St flight 4+ 8 flight 3 to Zheng 2. Cα4
trenching of silicon substrate using gas added with etc.
After confirming that undercutting in the buried layer was prevented by etching, but etching progressed to a bottle-like shape, a literature search was conducted to find out whether there was a gas that could prevent bottle-like etching, but the existence of such a gas was not found. I could not find any literature reporting this. Therefore, the inventor conducted experiments on etching with the addition of various gases, and confirmed that when chloroform (CHCf!3) was added, the trench 16 was etched straight in the vertical direction.
エツチングが終了した後でトレンチの側壁16aを観測
したところ、側壁16a上とPSG膜、窒化シリコン膜
、5i02膜の側壁上に堆積物が存在することを認め、
それの分析をなしそれがカーボン、水素、シリコンの組
成物(CxHySi)であることを確認した。かかる堆
積物が被着すると、RIEでは直進するイオンでエツチ
ングしてゆくのであるから、PSG膜上の堆積物はイオ
ンで除去され、また溝の底ではシリコンのエツチングと
堆積物の生成とが同時に進行する一方で、トレンチの側
壁16a上の堆積物はエツチングされることなく残る。When the sidewall 16a of the trench was observed after the etching was completed, it was found that deposits were present on the sidewall 16a and on the sidewalls of the PSG film, silicon nitride film, and 5i02 film.
Analysis of it confirmed that it was a composition of carbon, hydrogen, and silicon (CxHySi). When such deposits are deposited, they are etched by ions traveling straight in RIE, so the deposits on the PSG film are removed by ions, and silicon etching and deposit formation occur simultaneously at the bottom of the trench. While etching progresses, the deposits on the trench sidewalls 16a remain unetched.
事実、所定の深さのトレンチがエツチングされた後には
、側壁16a上にのみ堆積物が残り、それをプラズマ0
2によって除去することが必要である。In fact, after a trench of a given depth has been etched, deposits remain only on the sidewalls 16a, which are exposed to plasma
It is necessary to remove it by 2.
本発明の方法は、第1図に示されるリアクティブ・イオ
ン・エッチング装置21を用い、カソード23と基板1
1との間にプラズマ28を発生させ、次いでCP、2と
CHび3、またはSi便、十便2+CHα3を混合して
導入管25から装置21内に供給する。The method of the present invention uses a reactive ion etching apparatus 21 shown in FIG.
Plasma 28 is generated between 1 and 1, and then CP, 2 and CH 3, or Si feces and 10 feces 2+CHα3 are mixed and supplied into the device 21 through the introduction pipe 25.
び2 + CI+CE 3の実施例において、便2:C
Hα3=1:1の比率にして良好な結果が得られた。一
般に、II、f:2を1にして、CHα3は0.5〜1
.5の範囲内に設定すると本発明の目的を達成しうろこ
とが確かめられた。and 2 + CI + CE 3 examples, Stool 2:C
Good results were obtained with a ratio of Hα3=1:1. Generally, II, f:2 is set to 1, CHα3 is 0.5 to 1
.. It was confirmed that the object of the present invention could be achieved by setting it within the range of 5.
さらにSiαq+α2+CHIJ3についても実験をす
L/、(SicJ!、、+ +CJ!2 ) : C
)IC[! 3 = 3 : 1にして同様に満足すべ
き結果を得たもので、(SiCJ?、、4+α2):C
Hα3を2〜4:1にして所期の目的を達成することが
できた。Furthermore, we will also experiment with Siαq+α2+CHIJ3L/, (SicJ!,, + +CJ!2): C
) IC [! 3 = 3: 1 and similarly satisfactory results were obtained, (SiCJ?, 4+α2):C
The desired objective could be achieved by adjusting Hα3 to 2 to 4:1.
以上述べてきたように本発明によれば、シリコン基板の
トレンチ・エツチングにおいて、ボトル形状のエツチン
グやアンダカットの発生が防止され、設計通りの寸法の
トレンチのエツチングが可能となるので、作られる半導
体装置の信頼性と微細化の向上に効果がある。As described above, according to the present invention, bottle-shaped etching and undercuts can be prevented from occurring in trench etching of a silicon substrate, and trenches with the designed dimensions can be etched, thereby allowing semiconductors to be manufactured. This is effective in improving device reliability and miniaturization.
第1図は本発明実施例断面図、
第2図は本発明によるトレンチの断面図、第3図は従来
例断面図、
第4図は従来例の問題点を示す断面図である。
第1図ないし第4図において、
11はシリコン基板、
12は SiO2膜、
13は窒化シリコン膜、
14はPSG膜、
15は窓、
16はトレンチ、
ITは埋没層、
18は翼状部、
19は堆積物、
21は石英ジャー、
22はサセプタ、
23はカソード、
24はI?F発振器、
25はガス導入管、
26は排気系、
27は冷却系、
28はプラズマである。
代理人 弁理士 久木元 彰
復代理人 弁理士 大 菅 義 之
本槽些8月ツ≧がt伊JMi図
第1 図
不膏すj:よるトしンナ#IfOl!]72図
第3図
イオ末例めP」月、@、1足Ta
第4図FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view of a trench according to the present invention, FIG. 3 is a cross-sectional view of a conventional example, and FIG. 4 is a cross-sectional view showing problems in the conventional example. 1 to 4, 11 is a silicon substrate, 12 is a SiO2 film, 13 is a silicon nitride film, 14 is a PSG film, 15 is a window, 16 is a trench, IT is a buried layer, 18 is a wing-shaped portion, and 19 is a 21 is a quartz jar, 22 is a susceptor, 23 is a cathode, 24 is an I? 25 is a gas introduction pipe, 26 is an exhaust system, 27 is a cooling system, and 28 is a plasma. Agent Patent Attorney Akifuku Agent Patent Attorney Yoshio Suga ] 72 Figure 3 Io final example P'' Moon, @, 1 foot Ta Figure 4
Claims (1)
6)をリアクティブ・イオン・エッチングでエッチング
するにおいて、 塩素または塩素系ガスにクロロホルム(CHCl_3)
ガスを添加することを特徴とするエッチング方法。[Claims] A vertically straight trench (1) is formed in a semiconductor substrate (11).
6) When etching with reactive ion etching, chlorine or chlorine-based gas is mixed with chloroform (CHCl_3).
An etching method characterized by adding gas.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21922386A JPS6376329A (en) | 1986-09-19 | 1986-09-19 | Etching method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21922386A JPS6376329A (en) | 1986-09-19 | 1986-09-19 | Etching method |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6376329A true JPS6376329A (en) | 1988-04-06 |
Family
ID=16732133
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP21922386A Pending JPS6376329A (en) | 1986-09-19 | 1986-09-19 | Etching method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6376329A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0936679A1 (en) * | 1994-03-30 | 1999-08-18 | Matsushita Electronics Corporation | Method of manufacturing semiconductor devices having a built-in capacitor |
-
1986
- 1986-09-19 JP JP21922386A patent/JPS6376329A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0936679A1 (en) * | 1994-03-30 | 1999-08-18 | Matsushita Electronics Corporation | Method of manufacturing semiconductor devices having a built-in capacitor |
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