TW495910B - Manufacturing method of dual damascene structure - Google Patents

Abstract

According to the invented manufacturing method of dual damascene structure, a protection layer of the protection wall is formed at the periphery of the contact window, which is on the second etch stop layer inside the contact window and can be embedded into the groove when etching process is conducted, before the embedded groove is etched. Therefore, it is capable of eliminating the punch-through problem caused by etching through the first etch stop layer. In addition, the faceting effect caused by the junction between contact window and embedded groove can also be eliminated. Accordingly, the insulation effect can be assured.

Description

丄 υ ------ 881 Chi-ί: _1_ Japanese article five. Description of the invention (i) ------- ^ The present invention is related to the manufacturing of dual damascene structure. In particular, the invention relates to a manufacturing method of a double-embedded structure that can eliminate the faceting effect created by the interface between the contact window and the embedded groove and reduce the insulation effect. In recent years, in order to meet the development of component size reduction and increase the speed of component operation, copper metal with low resistance constant and high electron migration resistance has gradually been used as the material of metal interconnects to replace the previous Shao metal Process technology. … Metal copper itself has many inherent advantages, such as: (1) low resistance characteristics' its resistance value is 1 · 7 " Q-cm, and aluminum is 2 · 7 // Ω-cm;, (2 / ) Good resistance to electron migration; (3) Good resistance to stress-induced void formation and so on. The above advantages greatly help the characteristics of the component, such as faster speed, can reduce cross talk (Cross Talk) and have a small RC time constant. Although some physical properties of copper have great advantages for application to components', copper has the problem of being difficult to etch. Therefore, in order to solve this problem: the so-called damascene process is proposed. The inlay process is different from the traditional metallization process in which a metal pattern is first defined and then the groove is filled with an insulating layer. The method is to first engrav the groove of the metal wire on a flat insulating layer, and then place the metal Layers are filled in, and finally excess metal is removed by chemical mechanical polishing (Cjjp) to obtain a flat structure with metal embedded in the insulating layer. The inlay process has the following advantages over the traditional metallization process: (1) it can keep the surface of the substrate flat at any time; (2) it can exclude that the insulating material is not easy to fill the metal wire in the traditional process

0503-4358TW1; claire.ptc page 4 495910

Disadvantages of the gap; (3) In addition, the etching of copper metal can solve the problem of difficult etching of metal materials. The structure and guidance of the contact window in the process of the traditional interconnection of Tetumhong + and Erfu makes the entire process step extremely complicated. Disadvantages: Develop a dual damascene process to perform two selective money engravings, respectively, below the insulation =: touch the upper insulation layer to engraved the embedded groove for the inner line to mine out What: Once the barrier layer of the metal wire and the conductive plug is completed, and the conductive effect is filled into the contact window and the inner line into the groove, the process steps are simplified in recent years. In order to reduce the size of the matching components, The need to develop and increase the speed of element 2 and copper metal with low resistance constant and high electron migration resistance has gradually been used as the material of metal interconnects to replace the previous aluminum metal process technology. Copper metal's mosaic interconnect technology can not only reduce the interconnect size and reduce the Rc time delay, but also solve the problem of difficult copper etching, so it has become the main development trend of multiple interconnects today. Please refer to Figs. 1 (a) to (c), and Figs. (A) to (c) are cross-sectional views illustrating an example of a manufacturing method of a conventional dual mosaic structure. The manufacturing method of the conventional dual damascene structure is applied to a semiconductor substrate 10 having a conductive portion (such as' copper, polycrystalline silicon, etc.), and the manufacturing method of the conventional dual damascene structure includes the following steps. (1) As shown in FIG. 1 (a), 'on the above-mentioned semiconductor substrate 10, a first post-etch stop layer 11 0 (for example, nitride nitride) and a first insulation layer are sequentially formed.

495910

Layer 112 (e.g., oxidized stone), second epitaxial stop layer 114 (e.g., silicon nitride), second insulating layer 1 i6 (e.g., silicon oxide), and anti-reflection shielding layer 11 8 (e.g., oxynitride Shi Xi). (2) As shown in FIG. 1 (b), a photolithography (Photolithography) technique is used to form a photoresist layer 120 having an opening 122 for defining a contact window, and then the photoresist layer 120 is used as a mask, and The above-mentioned anti-reflection shielding layer 丨 8, the second insulation layer 116, the second etch stop layer 114 and the first insulation layer 112 are etched through the openings 1 to 22, and then the etching is terminated at the first etch stop layer 丨 丨Form a contact window 24.

(3) As shown in FIG. 1 (c), a photoresist layer 13o having an opening 132 for defining an embedded groove is formed by a photolithography technique, and the photoresist layer 13G is used as a mask. The anti-reflection shielding layer 118 and the second insulating layer 丨 6 are etched through the opening 进而, and then the etching is terminated at the second etch stop layer 114 to form the embedded recess 134. Finally, the method of making a conventional double-panel structure with copper metal (not shown 'as shown in item 1 (c)') is to etch through the first final etch when the embedded groove 134 is etched. Alpha stop layer 110, which causes a problem of punch —

In: 5 adjacent wounds 102 form a recessed portion 142, and at the same time, the planar (144) effect caused by the interface between the contact window 124 and the upper = embedded groove 134 reduces the insulation effect. To solve this problem, %% have proposed another method, as shown in Figure 2. Please refer to Figs. 2 (a) to ⑷. Figs. 2 to ⑷ show cross-sections for explaining another example of the manufacturing method of the conventional dual mosaic structure.

Face view. &# 份 202 f The manufacturing method of the double-embedded structure is applied to a semiconductor substrate 20 having a conductive portion, such as 'steel, polycrystalite, etc.' The manufacturing method includes the following steps. The sequence is as shown in FIG. 2 (a). On the semiconductor substrate 20, a 2U f etching stopper layer 210 (for example, silicon nitride), a first insulation / silicon layer is used. (E.g., silicon oxide), The second etch stop layer 214 (for example, nitrogen? Is / second insulating layer 216 (for example, silicon oxide) and anti-reflection mask 8 (for example, silicon oxynitride). Take $ j 2) as shown in FIG. 2 (b) As shown, a photoresist layer 22 with a contact window opening 222 is formed by lithography technology, and then the photoresist layer is used as a mask, and the antireflection shielding layer and the second through the opening 222 are etched. The insulating layer 2 1 6, the second etching stop layer 21 4 and the first insulating layer 12 2 are further etched to stop at the first etching stop layer 2 丨 0 to form a contact window 2 2 4. (3) As shown in FIG. 2 (c), 'the protective layer 226 (such as an organic bottom anti-reflection layer (Bottom ARC, BARC, which has a thickness of 900 angstroms) of the bottom of the contact window 224 and the anti-reflection shielding layer 218 is formed before the above-mentioned contact window 224. Above, or 600 Angstroms, covering the second layer) 'The photolithography technique is used to form a photoresist layer 230 having an opening 232 defining a recessed recess. (4) As shown in FIG. 2 (d), the above The photoresist layer 230 is a mask, and the anti-reflection shielding layer 2 1 8 and the second insulating layer 2 1 6 are engraved through the opening 2 3 2, and the etching is terminated at the second etching stop layer 2 丨 4 to An embedded groove 234 is formed. Finally, a copper metal (not shown) is filled. However, as shown in FIG. 2 (d), such a conventional dual-inlay structure is made.

0503-4358TWF1: claire.ptc Page 7

Description of the Invention (5) Although a method can eliminate the problem of erosion and penetration, it is also combined with the upper, ten, and ^ two termination layers 210 and the flat contact caused by the contact surface 1 ^ 4 and the above-mentioned recessed recess. The groove 234 has a lesson ::: up) effect 'and reduces its insulation effect. -Kind of dual-mosaic structure] J ::: 2 :: ^ is provided on the body substrate, and the above-mentioned dual-mosaic structure = semi-conductor on the semiconductor substrate is sequentially happy I :: method includes the following steps : Dazzle to form the first money engraving termination layer, milk this layer, the second etch termination layer and the second insulation layer: binding: U-insulation layer, the second engraved line stop extension, ',,, from the above The first insulation termination layer is formed to form a '-first: insulation layer and the money is engraved to the above-mentioned first-name engraving to form an embedding =: = the last-name is engraved to the above-mentioned second remaining-term termination layer, and a protective wall is formed around the above contact window. θ In the first etch stop layer π # ，, the protective layer is an organic bottom anti-reflection layer, and the I *, f, and second insulating layers are as follows: the mountain reaches up to the y-to-- ratio of the first-etched gas α For i 5 ~ 2 2. Into the groove layer and the second etch stop sound. Two γ The first etch is terminated, the second insulation layer and the protection; screen: on the eve or? Sclerosing silicon. Furthermore, the upper reflection shielding layer is silicon oxynitride 'and the above-mentioned anti-step, and 02 is called 8 as the dagger = the above-mentioned protective wall, and the surname is inscribed with the above-mentioned embedded four-shot B to knife one-the person is engraved above The protective wall is sold according to the present invention: the window is made of a photoresist layer. Before entering the groove, the manufacturing method is prior to the above. Because the second etching contact "inner shape f" in the etching recess can form a protective wall around the contact window on the stop layer during etching. Guarantee

The problem of the protective layer should also be able to eliminate the penetration of the spear caused by the H-th stop layer; the contact window and the interface of the embedded groove can thus protect its insulation effect. The above-mentioned purpose, features, and advantages of the invention can be more obvious and easier: the preferred embodiment is given in detail, and it will be described in detail with the accompanying drawings [simple description of the drawings] Figure 1 (a) to (c) are cross-sectional views showing an example of a manufacturing method of the conventional double setting; Figures (a) to (d) are shown to illustrate the conventional method A cross-sectional view of another example of the manufacturing method of the double inlay; and FIGS. 3 (a) to (g) are cross-sectional views illustrating a manufacturing method of the structure of the present invention. Explanation of symbols 10, 20, 30 to semiconductor substrate; 102, 202, 302 to conductive parts; 11 0, 2 1 0, 3 1 0, 11 4, 2 1 4, 3 1 4 to etch stop layer;! 2, 212, 312, 116, 216, 316 ~ insulation layer; 118, 218, 318 ~ anti-reflection shielding layer; 120, 220, 320, 130, 230, 330 ~ photoresist layer; 132, 232, 332 ~ opening; 124, 224, 324 ~ contact window; 142 ~ depression; 144,244 ~ planar effect; 134,234,334 ~ embedded groove; 226, 326 ~ protective layer; 342 ~ protective wall. [Embodiment] Please refer to Figs. 3 (a) to (g), and Figs. 3 (a) to (g) are cross-sectional views illustrating a method for manufacturing a dual mosaic structure of the present invention. this

0503-4358TWF1; claire.ptc page 9 495910

The manufacturing method of the inventive dual damascene structure is applicable to a semiconductor substrate 30 having a conductive portion 30 (for example, copper, polycrystalline silicon, etc.), and the manufacturing method of the dual damascene structure of the present invention includes the following steps. ^ Step 1: As shown in FIG. 3 (a), a first remaining stop layer 310, a first insulating layer 31, a second etching stop layer 314, and a second insulating layer are sequentially formed on the semiconductor substrate 30. 3 丨 6. An anti-reflection shielding layer 3 1 8 may be formed on the second insulating layer 3 丨 6.

For example, 'the first etching stop layer 310 (for example, silicon nitride or silicon oxynitride), the first insulating layer 3 1 2 (for example, silicon oxide, etc.), and the second The etch stop layer 3 1 4 (for example, silicon nitride or silicon oxynitride, etc.) and the second insulating layer 31 6 (for example, silicon oxide). An anti-reflection shielding layer 318 (for example, silicon nitride or silicon oxynitride) may be formed on the second insulating layer 316. Step two, as shown in FIGS. 3 (b) and (c), the second insulating layer 316, the first etching stop layer 3 丨 4, and the first insulating layer 3 丨 2 are etched to the first remaining stop layer. 310 to form a contact window 324. For example, as shown in FIG. 3 (b), a photoresist layer 32o having an opening 322 for defining a contact window is first formed by a lithography technique, and then the photoresist layer is formed as shown in FIG. 3 (c). mo is a mask, and the anti-reflection shielding layer 3 丨 8, the second insulating layer 3 丨 6, the second etch stop layer 314, and the first insulating layer 312 are etched through the opening Mg, and the etching is terminated at the first etch The layer 310 is terminated to form a contact window 324. Finally, the photoresist can be removed

Layer 320. Step 3 As shown in FIG. 3 (d), a protective layer is formed in the contact window 324. For example, a protective layer 326 is covered in the contact window 324 and the anti-reflection shielding layer 318, and the protective layer 326 may be etched. Those who can produce a large amount of polymer at times, such as organic bottom anti-reflection layer (Bottom ARC, BARC, whose thickness is about 700 Angstroms to 500 Angstroms). Step 42, as shown in (e) and (f) of FIG. 3, are etched through the second insulating layer 316 to the second etch stop layer 314 to form a recessed recess, H is embedded in the recessed recess 334. A protective wall 342 is formed around the contact I & 324 on the second etch stop layer 314. As shown in Figure (e), the photoresist layer 33 with the opening 332 for injecting into the groove is formed by the photolithography technique. The photoresist layer 330 is used as a mask, and The above-mentioned anti-reflection shielding layer 318 and the second insulating layer 316 are etched through the circle 332, and the etching ends at the above-mentioned second remaining termination layer 314, and 334. The engraved gas of the above-mentioned embedded groove 334 is ′, and the ratio of CxFy's 乂 antisense in Bazhong can be 15 ~ 2 2 (for example: C4F8, etc.), which is the same as the organic bottom anti-reflection layer 326. 8 sm wall 342 (the height is about 3 Angstroms to 3 Angstroms). The surface of the second contact layer 314 on the second stop layer 314 in the product ^ enters the groove 334 at the plane caused by the contact between the contact platform and the embedded groove 334. The effector can ensure its insulation effect by amending the 495910 case number 88112075 V. Description of the invention (9). Step 5 As shown in Figure 3 (g), the protective wall can be removed. For example, the protective wall made of a polymer is etched in two steps using 〇2 and & Fs as an etching gas. For example, plasma treatment is performed with 02 / Ar and dagger / ⑶ / fiber to remove the protective wall 342 described above. Finally, the dry resist and wet etching can be used to remove the photoresist layer 33 and the protective layer 326, and the etching gas of CDF / 〇2 / Ar can be used to etch and remove the two remaining stop layers located in the embedded recess Mg. 314 and the first momentary termination layer located in the contact window 324. As described above, the double setting according to the present invention is performed by the μI 仏 method before the embedded recess is etched. The protection of the protective wall is formed inside the two-cutter cooker in the rest of the time, so it can be eliminated; the erosion can be eliminated by contacting the window and the recessed recess. The plane effect can ensure its insulation effect: the thickness of 2 is more than 90 0 Angstroms, or _ Ang is covered by two |, small mouth officials use it, and it can also eliminate the thickness effect of the contact window and the recessed surface 2: , Thus ensuring its insulation effect. The plane caused by the interface Although the present invention has been disclosed in the preferred embodiment to define the present invention as above, anyone skilled in this art is not using the god and the range M, and can be changed and moisturized; therefore = away from the invention The definition of the scope of patent application attached to the essence of the present invention is the scope of protection of the present invention 0503-4358TWF1; claire.ptc page 12

Claims (1)

h A double-damascene structure is used to manufacture 4A and ancient semiconductor substrates. See the methods +, =, and 艳, which are applicable to the steps with conductive parts. The manufacturing method of the top-back double-damascene structure includes the following body substrates: 1 ~ 2 · 2 ㈣ gas in the above semi-conductive engraving "layer stop layer, insulating layer ^ 1¾ Γ ^ Υ ^ 1 · 5-2. 2 ^ ^ IJ Λ ft ^ i ^ ^-etch stop layer T: soil: and The first insulating layer is etched to the above & to form a contact window; 50 to 200; 妾 :: a protective layer is formed inside, the thickness of the protective layer is,, and M, and the embedded recess is formed through the first. Tenon τ: ϋ is engraved to the second etch stop layer, and the contact window on the layer ^ surrounds the second jie / the second etch stop reflective layer embedded in the groove. ° The thin protective wall is formed, and the protective layer is an organic bottom resistance. Method: Manufacture method of the dual mosaic structure described in item 1 of the scope of claim 3 is as described in claim 1-the insulating layer and the second insulating layer are oxidized stone. Manufacture of double-damascene structure or oxynitride. —Etch stop layer and second etch stop layer Xi nitrogen fossil method for producing U 2 4 which cover layer 3 of the item of interest range dual damascene structure., The second insulating layer is formed between said anti-reflective layer and the protective cover 0503-4358TW1; claire.Ptc page 13 1 · Except for the manufacture of the dual mosaic structure described in item 4 of the patent application 5910 VI-Case No. 8811207 ^ _ Ding-^ Patent application method ^ Law 'which The above-mentioned anti-reflection shielding layer is oxynitride. 6. The manufacturing method of the patent application No. 丨, 2, 3, 4, 4, and σ structure, which further includes removing the double mosaic method wall curtain described in item 2 and 5.丄 7. The steps of 、 L / mountain retaining wall as described in item 6 of the scope of patent application. , 丄 Αφρ / Π ^ Γ Ϊ? ^ AL · 4 Θ and the structure of the mosaic; Pi Shi, Zhong Yi 02 and think that the money carved gas k square water knife one-man etched the above protection 8 · Such as the scope of patent application 7 τ5 The manufacturing method of etching the above-mentioned embedded quadruple and the dual-damascene structure and the contact window are based on the photoresist layer. 0503-4358TWF1; claire.ptc page 14