JPH03248424A - Dry etching - Google Patents
Dry etchingInfo
- Publication number
- JPH03248424A JPH03248424A JP4638390A JP4638390A JPH03248424A JP H03248424 A JPH03248424 A JP H03248424A JP 4638390 A JP4638390 A JP 4638390A JP 4638390 A JP4638390 A JP 4638390A JP H03248424 A JPH03248424 A JP H03248424A
- Authority
- JP
- Japan
- Prior art keywords
- polysilicon
- etching
- trifluoride
- nitride
- frequency power
- 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
- 238000001312 dry etching Methods 0.000 title claims description 9
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims abstract description 32
- 229920005591 polysilicon Polymers 0.000 claims abstract description 32
- 238000005530 etching Methods 0.000 claims abstract description 29
- 239000007789 gas Substances 0.000 claims abstract description 29
- UNRFQJSWBQGLDR-UHFFFAOYSA-N methane trihydrofluoride Chemical compound C.F.F.F UNRFQJSWBQGLDR-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 7
- QKCGXXHCELUCKW-UHFFFAOYSA-N n-[4-[4-(dinaphthalen-2-ylamino)phenyl]phenyl]-n-naphthalen-2-ylnaphthalen-2-amine Chemical compound C1=CC=CC2=CC(N(C=3C=CC(=CC=3)C=3C=CC(=CC=3)N(C=3C=C4C=CC=CC4=CC=3)C=3C=C4C=CC=CC4=CC=3)C3=CC4=CC=CC=C4C=C3)=CC=C21 QKCGXXHCELUCKW-UHFFFAOYSA-N 0.000 claims description 6
- 230000000694 effects Effects 0.000 abstract description 4
- 239000000463 material Substances 0.000 abstract description 3
- 229910052785 arsenic Inorganic materials 0.000 abstract description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 abstract description 2
- 230000008878 coupling Effects 0.000 abstract description 2
- 238000010168 coupling process Methods 0.000 abstract description 2
- 238000005859 coupling reaction Methods 0.000 abstract description 2
- -1 nitride trifluoride Chemical class 0.000 abstract 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract 2
- 239000012495 reaction gas Substances 0.000 abstract 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 abstract 1
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 239000000470 constituent Substances 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 238000003754 machining Methods 0.000 abstract 1
- 239000000377 silicon dioxide Substances 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- GVGCUCJTUSOZKP-UHFFFAOYSA-N nitrogen trifluoride Chemical compound FN(F)F GVGCUCJTUSOZKP-UHFFFAOYSA-N 0.000 description 5
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- ZQXCQTAELHSNAT-UHFFFAOYSA-N 1-chloro-3-nitro-5-(trifluoromethyl)benzene Chemical compound [O-][N+](=O)C1=CC(Cl)=CC(C(F)(F)F)=C1 ZQXCQTAELHSNAT-UHFFFAOYSA-N 0.000 description 1
- XPDWGBQVDMORPB-UHFFFAOYSA-N Fluoroform Chemical compound FC(F)F XPDWGBQVDMORPB-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Drying Of Semiconductors (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は半導体装置製造方法において不純物が注入され
たポリシリコン（以下単にポリシリコンと記す）のドラ
イエツチング方法に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for dry etching polysilicon into which impurities have been implanted (hereinafter simply referred to as polysilicon) in a semiconductor device manufacturing method.
〈従来の技術〉
従来のポリシリコンのエツチングでは、取り扱いの容易
さから弗素系ガスを用いる場合、四弗化炭素（以下ＣＦ
４と記す）単体、或いはＣＦ４と酸素（以下０□と記す
）の混合ガスを使用してきた。<Conventional technology> In conventional etching of polysilicon, when using a fluorine-based gas for ease of handling, carbon tetrafluoride (hereinafter referred to as CF) is used.
4) or a mixed gas of CF4 and oxygen (hereinafter referred to as 0□) have been used.
〈発明が解決しようとする課題〉
しかしながら、ＣＦ、を使用した場合は、その解離エネ
ルギーが高いので、高いウェハ温度と大きな高周波電力
を要し、ポリシリコンのマスクレジストおよび下地材料
（例えばＳｉｎｇ）に対するエツチングレート比（以下
選択比と記す）が低く、また、弗素ラジカルの影響でア
ンダーカットを生じ易いという問題があった。<Problems to be Solved by the Invention> However, when CF is used, its dissociation energy is high, so high wafer temperature and high frequency power are required, and it is difficult to use for polysilicon mask resists and underlying materials (for example, Sing). There were problems in that the etching rate ratio (hereinafter referred to as selectivity) was low and undercuts were likely to occur due to the influence of fluorine radicals.
本発明は上記事情に鑑みて創案されたものであって、ポ
リシリコンのドライエツチングにおいて、弗素系ガスを
使用して、選択比が高く、アンダーカットを生じにくい
ポリシリコンのドライエツチング方法を提供することを
目的としている。The present invention was devised in view of the above circumstances, and provides a polysilicon dry etching method that uses a fluorine-based gas, has a high selectivity, and is less likely to cause undercuts. The purpose is to
く課題を解決するための手段〉
上記問題を解決するために本発明のドライエツチング方
法は、不純物が注入されたポリシリコンをエツチングチ
ャンバーに設置後、エツチングチャンバーに、反応性ガ
スとして、三弗化窒素が２０乃至５０体積％含有された
三弗化メタンと三弗化窒素との混合ガスを導入して前記
ポリシリコンをエツチング加工するようにしている。Means for Solving the Problems> In order to solve the above problems, the dry etching method of the present invention comprises placing polysilicon injected with impurities in an etching chamber, and then injecting trifluoride into the etching chamber as a reactive gas. The polysilicon is etched by introducing a mixed gas of methane trifluoride and nitrogen trifluoride containing 20 to 50% by volume of nitrogen.
〈作用〉
反応性ガスとして、室温で小さい高周波電力で解離する
三弗化窒素と、小さい高周波電力では堆積物の生じやす
い三弗化メタンを混合したガスを用いられている。従っ
て、マスクとなるレジストやポリシリコン下のＳｉＯ□
への損傷が少なく、レジストやＳｉＯ□に対するポリシ
リコンの選択比が大きくなる。また、三弗化メタンの堆
積効果によりポリシリコン側壁のエツチングが抑制され
、サイドエッチが少なくなる。<Operation> As the reactive gas, a mixture of nitrogen trifluoride, which dissociates at room temperature with a small high frequency power, and trifluoride methane, which tends to form deposits with a small high frequency power, is used. Therefore, SiO□ under the resist and polysilicon that serves as a mask
There is less damage to the resist, and the selectivity of polysilicon to resist and SiO□ is increased. Furthermore, the deposition effect of methane trifluoride suppresses etching of the polysilicon sidewalls, resulting in less side etching.
〈実施例〉 以下、本発明の詳細な説明する。<Example> The present invention will be explained in detail below.
本実施例で用いたドライエツチング装置は、船釣な平行
平板型カソードカップリング方式〇枚葉式装置であり、
エンチングチャンバーにエツチングガスを導き高周波電
力を供給してプラズマを発生させる仕組みとなっている
。被エツチング材料は、ヒ素またはリンをイオン注入さ
れたポリシリコンである。反応性ガスとしてはＣＨＦ
３とＮＦ３との混合ガスを使用し、比較のためにＣＦ４
と０２との混合ガスを用いた。The dry etching device used in this example is a parallel plate type cathode coupling type single wafer type device used in a boat.
The mechanism is to introduce etching gas into an etching chamber and supply high-frequency power to generate plasma. The material to be etched is polysilicon implanted with arsenic or phosphorous. CHF as a reactive gas
A mixed gas of 3 and NF3 was used, and for comparison, CF4
A mixed gas of and 02 was used.
まず、第１の実施例を説明する。第１の実施例では、反
応性ガスとして前記したＣ）ＩＦ ｓとＮＦ３との混合
ガスを用い、反応性ガスの総流量、混合体積比（ＮＦ３
／ （ＣＨＦ３＋ＮＦｌ ） ）をパラメータとして
種々変更し、ポリシリコンのエツチングを行った。First, a first example will be described. In the first example, a mixed gas of C)IFs and NF3 described above is used as the reactive gas, and the total flow rate of the reactive gas and the mixing volume ratio (NF3
/ (CHF3+NFl)) was variously changed as a parameter, and polysilicon was etched.
第１図にポリシリコンのエッチレートとポリシリコンの
対Ｓｉｎｇ選択比の反応性ガス総流量依存性を示す。曲
線１はこのエッチレートを、曲線２は選択比を示す。い
ずれも反応性ガスの総流量が増加すると増大している。FIG. 1 shows the dependence of the polysilicon etch rate and the polysilicon selectivity to Sing on the total reactive gas flow rate. Curve 1 shows this etch rate and Curve 2 shows the selectivity. Both increase as the total flow rate of reactive gas increases.
第２図にポリシリコンのエッチレートとポリシリコンの
対５ｉＯｚ選択比のエツチングガス混合比依存性を示す
。曲線１はこのエッチレートを、曲線２は選択比を示す
。ＮＦ３の成分比の増加に伴ってエッチレートは増大す
るが、選択比は減少する。FIG. 2 shows the dependence of the polysilicon etch rate and the polysilicon selectivity to 5 iOz on the etching gas mixture ratio. Curve 1 shows this etch rate and Curve 2 shows the selectivity. As the component ratio of NF3 increases, the etch rate increases, but the selectivity decreases.
なお、図示していないが、反応性ガスの総流量およびＮ
Ｆ□の成分比の少ない方がアンダーカット量も減少する
。従って、Ｎｈの成分比が２０〜５０堆積％の範囲にお
いて選択比をあまり低下させることなく、大きいエッチ
レートを得られ、また、アンダーカットも減少できるこ
とがわかる。Although not shown, the total flow rate of reactive gas and N
The smaller the component ratio of F□, the smaller the amount of undercut. Therefore, it can be seen that when the Nh component ratio is in the range of 20 to 50% deposition, a large etch rate can be obtained without reducing the selectivity too much, and undercuts can also be reduced.
第１表は従来のドライエツチング方法と本実施例との比
較を示している。即ち、本実施例は従来例と比べるとポ
リシリコンのエッチレートが低いが、選択比およびアン
ダーカット量に関しては優れている。また、エツチング
形状は、混合比を変化させることによって順テーパーか
ら垂直まで制御可能である。Table 1 shows a comparison between the conventional dry etching method and this example. That is, this example has a lower polysilicon etch rate than the conventional example, but is superior in terms of selectivity and undercut amount. Furthermore, the etching shape can be controlled from a forward taper to a vertical shape by changing the mixing ratio.
第１表 次に、第２の実施例について説明する。Table 1 Next, a second example will be described.
第１の実施例と同様のガスによって、２ステツプのエツ
チングを試みた。即ち、ｌステップ目は第１の実施例と
同条件でジャストエッチまでエツチングを行い、２ステ
ップ目でオーバーエッチを行う方法である。このとき、
２ステツプ目は、ＣＨＦ、の混合比を１ステツプ目より
も大きくしているので、ポリシリコン下のＳｉＯ□との
選択比がより高くなっている。また、エツチングを２ス
テツプにすることによる形状変化は全く無い。Two-step etching was attempted using the same gas as in the first embodiment. That is, in the l-th step, etching is performed until just etching is performed under the same conditions as in the first embodiment, and in the second step, over-etching is performed. At this time,
In the second step, the mixing ratio of CHF is made larger than in the first step, so that the selectivity with respect to SiO□ under the polysilicon is higher. Moreover, there is no change in shape due to the two-step etching.
〈発明の効果〉
以上説明したように本発明のドライエツチング方法は、
不純物が注入されたポリシリコンをエツチングチャンバ
ーに設置後、エツチングチャンバーに、反応性ガスとし
て、三弗化窒素が２０乃至５０体積％含有された三弗化
メタンと三弗化窒素との混合ガスを導入して前記ポリシ
リコンをエツチング加工する。<Effects of the Invention> As explained above, the dry etching method of the present invention has the following effects:
After placing the impurity-injected polysilicon in an etching chamber, a mixed gas of methane trifluoride and nitrogen trifluoride containing 20 to 50% by volume of nitrogen trifluoride is introduced into the etching chamber as a reactive gas. The polysilicon is then etched.
従って、本発明のドライエツチング方法によると、ポリ
シリコンをエツチングするに際し、反応性ガスとしてＣ
Ｈｈ＋ＮＦ３の混合ガスを用いることによって、比較的
小さい高周波電力でレジストおよび５ｉＯｚに対して高
い選択比が得られ、且つ、アンダーカットのない垂直な
形状の側壁を有するエツチングを施行することができる
。Therefore, according to the dry etching method of the present invention, C is used as a reactive gas when etching polysilicon.
By using a mixed gas of Hh+NF3, a high selectivity to the resist and 5iOz can be obtained with a relatively small high frequency power, and etching can be performed with vertically shaped sidewalls without undercuts.
第１図および第２図は本発明の詳細な説明するための図
であって、第１図は、ポリシリコンのエッチレートとポ
リシリコンの対ＳｉＯ□選択比の反応性ガス総流量依存
性を示すグラフであり、第２図は、ポリシリコンのエッ
チレートとポリシリコンの対ＳｉＯ□選択比のエツチン
グガス混合比依存性を示すグラフである。1 and 2 are diagrams for explaining the present invention in detail, and FIG. 1 shows the dependence of the polysilicon etch rate and the polysilicon selectivity to SiO□ on the total reactive gas flow rate. FIG. 2 is a graph showing the dependence of the polysilicon etch rate and the polysilicon selectivity to SiO□ on the etching gas mixture ratio.
Claims (1)
ャンバーに設置後、エッチングチャンバーに、反応性ガ
スとして、三弗化窒素が２０乃至５０体積％含有された
三弗化メタンと三弗化窒素との混合ガスを導入して前記
ポリシリコンをエッチング加工することを特徴とするド
ライエッチング方法。(1) After placing the impurity-injected polysilicon in an etching chamber, methane trifluoride containing 20 to 50% by volume of nitrogen trifluoride and nitrogen trifluoride are added to the etching chamber as reactive gases. A dry etching method characterized by etching the polysilicon by introducing a mixed gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4638390A JPH03248424A (en) | 1990-02-26 | 1990-02-26 | Dry etching |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4638390A JPH03248424A (en) | 1990-02-26 | 1990-02-26 | Dry etching |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03248424A true JPH03248424A (en) | 1991-11-06 |
Family
ID=12745619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4638390A Pending JPH03248424A (en) | 1990-02-26 | 1990-02-26 | Dry etching |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03248424A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7858726B2 (en) | 2006-02-21 | 2010-12-28 | Asahi Kasei Chemichals Corporation | Process for producing low-molecular polyphenylene ether |
| US8889816B2 (en) | 2011-12-29 | 2014-11-18 | Shengyi Technology Co., Ltd. | Method for preparing phosphorus-containing polyphenylene oxide resin with low molecular weight |
-
1990
- 1990-02-26 JP JP4638390A patent/JPH03248424A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7858726B2 (en) | 2006-02-21 | 2010-12-28 | Asahi Kasei Chemichals Corporation | Process for producing low-molecular polyphenylene ether |
| US8889816B2 (en) | 2011-12-29 | 2014-11-18 | Shengyi Technology Co., Ltd. | Method for preparing phosphorus-containing polyphenylene oxide resin with low molecular weight |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5786276A (en) | Selective plasma etching of silicon nitride in presence of silicon or silicon oxides using mixture of CH3F or CH2F2 and CF4 and O2 | |
| US7049244B2 (en) | Method for enhancing silicon dioxide to silicon nitride selectivity | |
| US5013400A (en) | Dry etch process for forming champagne profiles, and dry etch apparatus | |
| US5286344A (en) | Process for selectively etching a layer of silicon dioxide on an underlying stop layer of silicon nitride | |
| US6069092A (en) | Dry etching method and semiconductor device fabrication method | |
| US20130224960A1 (en) | Methods for etching oxide layers using process gas pulsing | |
| US8133817B2 (en) | Shallow trench isolation etch process | |
| US20060186087A1 (en) | Etchant and method of use | |
| US7510976B2 (en) | Dielectric plasma etch process with in-situ amorphous carbon mask with improved critical dimension and etch selectivity | |
| Oehrlein et al. | Plasma-based dry etching techniques in the silicon integrated circuit technology | |
| JPH04326726A (en) | Dry etching method | |
| JPS60117631A (en) | Dry etching method of compound semiconductor | |
| KR0175688B1 (en) | Plasma ashing method with oxygen pretreatment | |
| US5880037A (en) | Oxide etch process using a mixture of a fluorine-substituted hydrocarbon and acetylene that provides high selectivity to nitride and is suitable for use on surfaces of uneven topography | |
| JPH11186229A (en) | Dry etching and manufacture of semiconductor device | |
| US6069087A (en) | Highly selective dry etching process | |
| US5968278A (en) | High aspect ratio contact | |
| US6653237B2 (en) | High resist-selectivity etch for silicon trench etch applications | |
| JPH03248424A (en) | Dry etching | |
| US7037843B2 (en) | Plasma etching method | |
| JPH06181190A (en) | Fabrication of semiconductor device | |
| JPH0472082A (en) | Dry etching method | |
| WO2000026954A1 (en) | Method of reducing stop layer loss in a photoresist stripping process using hydrogen as a fluorine scavenger | |
| KR20020066011A (en) | Dry etching process for the high Efficient SiC devices | |
| JPH11111686A (en) | Low-pressure plasma etching method |