TWI259531B - Method of etching dual anti-reflection layer - Google Patents

Abstract

The present invention relates to a method of etching dual anti-reflection layers, comprising: first, providing a substrate formed with a defined layer thereon; then sequentially forming a first anti-reflection layer, a second anti-reflection layer, and a photoresistant pattern layer, which has at least one aperture; and finally, simultaneously etching the second and the first anti-reflection layers below the aperture so as to expose the surface of the defined layer, wherein CF4, C4F6, CHF3, O2, and Ar are used as etching reagent gases. Moreover, the first anti-reflection layer is an inorganic anti-reflection layer, and the second anti-reflection layer is an organic anti-reflection layer.

Description

1259531

V. INSTRUCTIONS INSTRUCTIONS (1) Technical field to which the invention belongs: The relevant case in this case was the application for the Republic of China Patent No. 9 〇丨丨9 7 9 5 of the Republic of China on August 13, 1990, whose invention name is " An indentation method with a two-layer resist process." The present invention relates to a semiconductor process, and more particularly to an etching method using a double-layer anti-reflection layer for processing a process window and improving a via hole (prof i 1 e ) ° * Previous technology:

As the integration of semiconductor integrated circuit components increases, the development of lithography processes becomes more and more important. In order to increase the resolution of the lithography process, the wavelength of the light source required for exposure is shortened to 2 nanometers ( Deep ultraviolet light (DUV) below nm). Since the substrate used in the semiconductor process or the metal layer formed on the body is a highly reflective material, problems such as standing wave effect and optical proximity effect are caused to reduce the lithography resolution and the pattern distortion.

In order to reduce the adverse effects caused by the reflection of the exposure light source in the photoresist layer, an anti-reflective coating (ARC) is usually formed between the photoresist layer and the defined layer, so that the photoresist layer can be controlled. Exposure effect. Conventionally, the types of anti-reflection layers are classified into organic and inorganic types, and are formed by spin coating, which is similar in nature to a photoresist layer, and thus has the effect of surface flattening. The light source is focused. The latter is formed by chemical vapor deposition (c h e m i c a 1 v a ρ 〇 r deposition, CVD) or sputtering, which can adjust the refractive index

1259531 V. Description of invention (2) (η) and extinction coefficient (k). However, the effect of a single anti-reflective layer is such that it does not improve the resolution of the lithography process and effectively improves the sidewall striation of the defined pattern, especially in processes with a line width of 1 μm (//m) or less. . In order to further enhance the tolerance of the lithography process, there is a double-layer resist or a technique using a double-layer anti-reflection layer. However, the former is prone to problems of scum or excessive critical dimension (CD) shift in the process. The latter requires an additional step to remove the double-layer anti-reflective layer, which complicates the process.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a method of using a two-layer anti-reflective layer in combination with a conventional single inorganic anti-reflective layer or organic anti-reflective layer to increase the lithography process tolerance. Another object of the present invention is to provide an etching method using a double-layer anti-reflection layer which simplifies the process steps by simultaneously etching a double-layer anti-reflection layer by a single etching step. θ

In accordance with the above objects, the present invention provides a method of etching using a double-layered anti-reflective layer, first providing a substrate on which a defined layer is formed. Next, a first anti-reflective layer is formed on the defined layer. Subsequently, a second anti-reflection layer is formed on the first anti-reflection layer. Next, a photoresist pattern layer is formed on the second anti-reflection layer, the photoresist pattern layer having at least one opening. Finally, the second and first anti-reflective layers under the opening are simultaneously etched to define the surface of the layer, wherein CF4, CJ6, CHF3, 〇2 and Ar are used as

1259531, invention description (3) Residual reaction gas. The layer defined above is a conductive layer or a dielectric layer, and the first anti-reflective layer is an inorganic anti-reflection layer having a thickness of 3 〇〇 8 8 Å and a thickness of the anti-reflective layer is 300 〜 An organic anti-reflective layer in the 800 angstrom range. The above described objects, features and advantages of the present invention will become more apparent and understood from

Hereinafter, an etching method using a double-layer anti-reflection layer according to an embodiment of the present invention will be described with reference to Figs. First, please refer to Fig. 1 to provide a substrate, such as a wafer, which is formed with active components, passive components or other well-known semiconductor components, and metal interconnects. Here, for the sake of simplicity, only a flat substrate is shown. Next, a defined layer 丨〇2 is formed on the substrate 1 ,. In the present embodiment, the dielectric hole (contact =1 e ) is defined in the damascene process as an example, and the defined layer 1 〇 2 Refers to a dielectric layer. However, it is to be noted that the present invention is not limited thereto, and the present invention is also applicable to defining a trench or a germane conductor layer, and the conductor layer may be a copper, aluminum metal layer or a germanium layer.

^ Next, please refer to Figure 2, to form a first anti-reflection in the range of 30 0: 800 angstroms on the dielectric layer 1 〇 2 by a conventional deposition technique such as chemical vapor deposition (CVD). Layer 1〇4. In this embodiment, the first anti-reflective layer 104 is an inorganic anti-reflective layer such as a tantalum nitride layer or a hafnium oxynitride layer. Thereafter, by spin coating to the first anti-reflection layer

1259531 V. INSTRUCTION DESCRIPTION (4) A second anti-reflection layer 1 〇 6 having a thickness in the range of 300 to 800 angstroms is formed on the 1 0 4 . The second anti-reflective layer 106 used herein is an organic anti-reflective layer such as Novolak and BARLi (bottom anti-reflective layer for i-line). The double-layer anti-reflection layer 1〇4,1〇6 constitutes a composite anti-reflection layer 107. Next, a photoresist layer 110 is formed over the composite anti-reflective layer 1 〇7, and then a photoresist pattern layer having a plurality of openings 109 is formed by exposing a lithography step to expose the second anti-reflection layer.丨 0 6 surface.

Next, the reference layer 3 is exposed to remove the dielectric anti-reflective layer 1〇7 under the openings 109 to expose the dielectric layer. In this embodiment, in order to simultaneously remove the second and first anti-reflective layers 1 0 6 , 1 0 4 to achieve the purpose of simplifying the process steps, CF4, QF6, CHF3, 〇2, and Ar are used as etching reaction gases. In conjunction with the use of a two-pole reactive ion re-etching (rie) machine. Among them, the flow rates of CF4, C4F6, CHF3, 〇2 & Ar are in the range of 40~100 seem, 4~10 seem, 1〇~30 sccm, ι〇~4〇sccm&i〇~1〇〇seem . Further, the working pressure of the etching reaction is in the range of 5 to 5 〇 mt, the power of the power is in the range of 100 to 90 0 W, and the bias power is in the range of 9 〇〇 2 〇〇〇 W.

Finally, referring to Fig. 4, a dielectric hole 102 is formed under the opening 1〇9 by a conventional etching step to remove the exposed dielectric layer 102 and expose the surface of the substrate 100. Next, the photoresist pattern layer 1 〇 8 is removed by a conventional photoresist stripping method such as an oxygen plasma ashing method. In addition, since the second anti-reflection layer 106 is an organic substance, it is removed when the photoresist pattern layer m is removed.

!259531 V. Description of the invention (5) To leave the first anti-reflection layer 1 〇 4. In this way, the production of the via hole is completed. The effect of the standing wave of the layer-by-layer technique is to make the outline of the hole. Removing this pair does not limit the scope of this and the scope of the effect. In the present invention, it is also possible to increase the sidewall generation in the application of the single inorganic antireflection layer. Furthermore, the shot layer is not a step. It has been better to know that this can be used as a modified patent range. The anti-reflection layer can be used with the preferred surface to add the lithography process stripe. (Striat can be used in the present invention. This embodiment is disclosed by the skilled person, in the retouching Therefore, the defined one is to solve the base reflection sensation on time to increase the lithography resolution and prevent the single layer etch step from being improved while the double layer anti-reflection layer is improved. The scope of protection of the present invention is not deviated from the present invention.

1259531 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing the formation of a defined layer on a substrate in accordance with an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing the formation of a double-layered antireflection layer and a photoresist pattern layer on the defined layer in Fig. 1. Fig. 3 is a schematic cross-sectional view showing the etching of the double-layered antireflection layer in Fig. 2; Figure 4 is a schematic cross-sectional view showing the layer defined in the etching of Figure 3. DESCRIPTION OF REFERENCE NUMERALS: 100~substrate; 1 0 2~dielectric layer; 1 0 4~first anti-reflection layer; 1 0 6~second anti-reflection layer; 1 0 7~compositive anti-reflection layer; 1 0 8~ light Resistive pattern layer; I 0 9~ opening; II 0~ interlayer hole.

0503-7906TWF(Nl) ; TSMC2001-1711 ; SPIN.ptd Page 9

Claims (1)

1259531 93110084 ; 呌曰 呌曰 呌曰 f 六 六 申请 申请 申请 申请 申请 申请 申请 申请 申请 · · · · · · · · · · · · · 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻 蚀刻Forming a first anti-reflection layer; forming a second anti-reflection layer on the first anti-reflection layer; forming a photoresist pattern layer on the second anti-reflection layer, the photoresist pattern layer having at least one opening; The second and the first anti-reflection layer under the opening are exposed to expose the surface of the defined layer by using a mixed gas as an etching reaction gas for performing a single etching step. 2: The etching of the double-layer anti-reflection layer as described in claim 1 of the patent application. The carbon-carbon mixture system includes CF4, CA, chf3 and 〇2 1 乍 as etching reaction gases. 2 3: The double-layer anti-reverse method described in claim i, wherein the layer is defined as a conductive layer or a dielectric layer. Etching 4 · The double-layer anti-reflection method described in the i-worker of the patent scope, wherein the first anti-reflection ^ ^ ^ day is the reflection layer is an organic anti-reflection layer. The τ layer and the second remedy 5, as described in the second aspect of the patent scope, wherein the etch reaction gas layer is etched, and the second aspect of the patent scope is the layer anti-reverse method, wherein CF, 兮pps for the first time ΛΠ 4 The C4F6, the CHF3 and the 02 flow rate eight w on xj 100 seem > 4-10 seem > in 〇π Λ Feng knife not in 40 ~ circumference. Van of sccm Etching of the double-layer anti-reflection layer as described in claim 4 1259531 Sixth, the scope of the patent application method, wherein the thickness of the first anti-reflection layer is in the range of 300 to 800 angstroms. 8. The method of the double-layer anti-reflection layer according to claim 4, wherein the thickness of the second anti-reflection layer is in the range of 300 to 800 angstroms: 9 · as claimed in the patent application The method for marking a double-layer anti-reflection layer according to the item 5, wherein the flow rate of the Ar is in the range of 1 〇 1 1 sccm. 1 〇·- A method for engraving a double-layer anti-reflection layer, which is suitable for defining a via hole, comprising the following steps: providing a substrate on which a dielectric layer is formed; forming an inorganic anti-reflection on the dielectric layer a reflective layer; forming an organic anti-reflective layer on the inorganic anti-reflective layer; forming a photoresist pattern layer on the organic anti-reflective layer, the photoresist pattern layer having at least one opening; and simultaneously engraving the opening under the opening The inorganic and anti-reflective layer is organic and exposed to expose the surface of the dielectric layer, wherein CF4, CHF3 and 〇2 are used as etching reaction gases for a single etching step. 1 1 The etching method of the double-layer anti-reflection layer as described in the first aspect of the patent application, further comprising the step of etching the exposed dielectric layer to form a via hole. The etching method of the double-layer anti-reflection layer according to the first aspect of the invention, wherein the etching reaction gas further comprises Ar. 1 3 · The etching method of the double-layer anti-reflection layer according to the first aspect of the patent application, wherein the CF4, the C4F6, the CHF3 and the 02 flow rate are respectively 40 to 1 00 sccm, 4 to l〇 Sccm, 10~3〇sccm&l〇~4Qsccn^々^. 0503-7906TWFl(Nl).ptc Page 11 1259531 _ Case No. 93110084_年月曰 _ Revision _ 6. Patent Application Range 1 4. The etching method of the double-layer anti-reflection layer as described in claim 10 of the patent application scope, The thickness of the inorganic anti-reflection layer is in the range of 300 to 800 angstroms. 1 5. The method of etching a double-layer anti-reflection layer according to claim 10, wherein the thickness of the organic anti-reflection layer is in the range of 300 to 800 angstroms. 1 6. The method of etching a double-layer anti-reflection layer according to claim 12, wherein the flow rate of the Ar is in the range of 10 to 1 0 0 s c c m . 0503-7906TWFl(Nl).ptc Page 12 1259531 Case No. 93110084 月 Amendment IV. Abstract of Chinese Invention (Invention name: etching method of double-layer anti-reflection layer) The present invention discloses an etching method of a double-layer anti-reflection layer. First, a substrate is provided on which a defined layer is formed. Then, a first anti-reflective layer, a second anti-reflective layer and a photoresist pattern layer are sequentially formed on the defined layer, and the photoresist pattern layer has at least one opening. Finally, the second and first anti-reflective layers under the α are simultaneously etched to expose the surface of the defined layer, wherein CF4, C4F6, CHF3, 02 & Ar are used as the etching reaction gas. Furthermore, the first anti-reflective layer is an inorganic anti-reflective layer, and the second anti-reflective layer is an organic anti-reflective layer. V. (1) The representative figure of this case is: Figure 3 (2), the representative symbol of the representative figure of this case is a simple description: 1 0 0~substrate; 1 0 2~dielectric layer; 1 0 4~first anti-reflection Layer; 1 0 6~ second anti-reflective layer; 1 0 7~ composite anti-reflective layer; 1 0 8~ photoresist pattern layer; 1 0 9~ opening. Sixth, English invention summary (invention name:) 0503-7906TWFl(Nl).ptc Page 2