UNDER LAYER COMPOSITION AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE
Under layer composition and methods of manufacturing semiconductor devices are disclosed. The method of manufacturing semiconductor device includes the following steps. A layer of an under layer composition is formed, wherein the under layer composition includes a polymeric material and a cross-linker, and the cross-linker includes at least one decomposable functional group. A curing process is performed on the layer of the under layer composition to form an under layer, wherein the cross-linker is crosslinked with the polymeric material to form a crosslinked polymeric material having the at least one decomposable functional group. A patterned photoresist layer is formed over the under layer. An etching process is performed to transfer a pattern of the patterned photoresist layer to the under layer. The under layer is removed by decomposing the decomposable functional group.
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Photolithography (or lithography) is frequently used in manufacturing semiconductor integrated circuits (IC). In a typical lithography process, a resist film is spin-coated on a surface of a silicon wafer and is subsequently exposed and developed to form a pattern for etching the silicon wafer. As semiconductor fabrication technology continues to scale down where functional density has generally increased while geometry size has generally decreased, there has been a demand for a reduction in resist film thickness and a better reflectivity control during exposure. Accordingly, some new material and/or new techniques in lithography have been developed. For example, some lithography processes use silicon-containing resist over a carbon-containing bottom anti-reflective coating (BARC) layer to reduce resist film thickness. For another example, some lithography processes use a tri-layer stack that includes a resist over a silicon-containing middle layer over a carbon-containing under layer. However, these approaches present new challenges.
For example, in the tri-layer approach, the carbon-containing layer is very difficult to remove, and thus dry etch process is applied. However, when the carbon-containing layer is formed over a dielectric layer, the removal of the carbon-containing layer may damage the dielectric layer therebeneath. This unavoidably reduces device reliability.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
The advanced lithography process, method, and materials described in the current disclosure can be used in many applications, including fin-type field effect transistors (FinFETs). For example, the fins may be patterned to produce a relatively close spacing between features, for which the above disclosure is well suited. In addition, spacers used in forming fins of FinFETs can be processed according to the above disclosure.
In some embodiments, the substrate 110 may also include other material layers or circuit patterns formed thereover. For example, the substrate 110 may further include one or more material layers to be patterned (by etching to remove or ion implantation to introduce dopants), such as a gate material stack to be patterned to form gates; or a semiconductor material to be patterned to form isolation trenches. In other embodiments, multiple semiconductor material layers, such as gallium arsenic (GaAs) and aluminum gallium arsenic (AlGaAs), are epitaxially grown on the substrate 110 and are patterned to form various devices, such as light-emitting diodes (LEDs). In some other embodiments, the substrate 110 includes fin active regions and three dimensional fin field-effect transistors (FinFETs) formed or to be formed thereon. The substrate 110 may include various doped features formed therein, such as doped well structure (e.g., a P-typed doped well and an N-type doped well).
In some embodiments, the dielectric layer 120 to be patterned is formed on the substrate 110. The dielectric layer 120 is patterned to form trenches for conductive lines or holes for contacts or vias, for example. In some embodiments, the dielectric layer 120 may be a low-k dielectric layer having a k value lower than 4, for example. In some embodiments, the dielectric layer 120 is a material such as, a fluorine-doped silicon dioxide, a carbon-doped silicon dioxide, a porous silicon dioxide, a porous carbon-doped silicon dioxide, a porous SiLK, a spin-on silicone based polymeric dielectric, or a spin-on organic polymeric dielectric.
Referring to
In some embodiments, as shown in
The cross-linker 136 is an organic cross-linker, for example. In some embodiments, the cross-linker 136 includes an aromatic structure, an aliphatic structure, a cycloalkyl structure, or a combination thereof. The cross-linker 136 includes at least one crosslinkable functional group (R2) 138a and at least one decomposable functional group (R3) 138b. In some embodiments, the crosslinkable functional group (R2) 138a and the decomposable functional group (R3) 138b are directly bonded.
The crosslinkable functional group (R2) 138a is capable of crosslinking with the reaction group (R1) 134a of the polymer 134 in the polymeric material. In some embodiments, the crosslinkable functional group (R2) 138a may be selected from the group consisting of a hydroxyl group, an alkoxyl group having a carbon number less than 6, an amine group, a thiol group, a ester group, an alkene group, an alkyne group, an epoxy group, an aziridine group, an oxetane group, an aldehyde group, a ketone group, and a carboxylic acid group.
The decomposable functional group (R3) 138b has weak chemical stability and thus is capable of being decomposed under a weak acid or base condition such as pH 4˜10. In some embodiments, the decomposable functional group (R3) 138b may be selected from the group consisting of an ester group, an ether group, a silyl ether group, an acetal group, a ketal group, an amide group, an imine group, an imide group, and a carbamate group.
In some embodiments, the under layer composition 130 may be substantially free of silicon. The under layer composition 130 may include a photoresist (or resist) that is either a positive-type or negative-type. In some embodiments, the under layer composition 130 may further include an additives and/or a dye. The additive may include various chemicals designed to modify the characteristics and enhance of the performance of the under layer composition 130. In some embodiments, the additives include surfactant, fluoro-containing groups, or both. The dye is sensitive to light and is able to modify the characteristics (such as refractive index n and extinction coefficient κ) of the under layer 140. In some embodiments, the under layer composition 130 also includes solvent when it is disposed over the substrate 110. In various example, the solvent includes isopropyl alcohol (IPA), propylene glycol methyl ether (PGEE), propylene glycol monomethyl ether acetate (PGMEA), H2O, ether, alcohol, ketone, or ester.
After coating on the dielectric layer 120, a curing process is performed on the layer of the under layer composition 130, so as to form the under layer 140. During the curing process, the polymers 134 and the cross-linker 136 interact with each other to form the under layer 140 as illustrated in
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For a better understanding of the embodiments of the disclosure, an example of the under layer composition is illustrated in
In some embodiments, the under layer has a crosslinked polymeric material with a decomposable functional group, which is derived from the cross-linker and has a weak chemical stability. Therefore, under a condition of pH 4˜10 such as using a mild wet solution, the decomposable functional group is decomposed and the crosslinked polymeric material is decrosslinked. Accordingly, the under layer is easily removed by the mild wet solution. In addition, compared with the dry etching process, since the under layer is removed under a mild wet solution, damage to the material layer such as a low-k dielectric layer beneath the under layer is prevented. Thus, the reliability or performance of the semiconductor device is improved.
In accordance with some embodiments of the present disclosure, an under layer composition includes a polymeric material and a cross-linker. The polymeric material includes at least one reaction group. The cross-linker includes at least one crosslinkable functional group and at least one decomposable functional group, the at least one crosslinkable functional group is capable of crosslinking with the at least one reaction group of the polymeric material, and the decomposable functional group is capable of being decomposed under a condition of pH 4˜10.
In accordance with some embodiments of the present disclosure, a method of manufacturing a semiconductor device includes at least the following steps. A layer of an under layer composition is formed, wherein the under layer composition includes a polymeric material and a cross-linker, and the cross-linker includes at least one decomposable functional group. A curing process is performed on the layer of the under layer composition to form an under layer, wherein the cross-linker is crosslinked with the polymeric material to form a crosslinked polymeric material having the at least one decomposable functional group. A patterned photoresist layer is formed over the under layer. An etching process is performed to transfer a pattern of the patterned photoresist layer to the under layer. The under layer is removed by decomposing the decomposable functional group.
In accordance with some embodiments of the present disclosure, a method of manufacturing a semiconductor device includes at least the following steps. An under layer is formed over a dielectric layer, wherein the under layer includes a crosslinked polymeric material including at least one decomposable functional group. A patterned photoresist layer is formed over the under layer. A first etching process is performed to transfer a pattern of the patterned photoresist layer to the under layer. A second etching process is performed to transfer the pattern to the dielectric layer by using the under layer as a mask. The under layer is removed by decrosslinking the crosslinked polymeric material through the at least one decomposable functional group.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
Claims
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6. A method of manufacturing a semiconductor device, comprising:
- forming a layer of an under layer composition, wherein the under layer composition comprises a polymeric material and a cross-linker, and the cross-linker comprises at least one decomposable functional group;
- performing a curing process on the layer of the under layer composition to form an under layer, wherein the cross-linker is crosslinked with the polymeric material to form a crosslinked polymeric material having the at least one decomposable functional group;
- forming a patterned photoresist layer over the under layer;
- performing an etching process to transfer a pattern of the patterned photoresist layer to the under layer; and
- removing the under layer by decomposing the decomposable functional group.
7. The method according to claim 6, wherein the polymeric material comprises at least one reaction group providing a crosslinking site, the at least one reaction group is selected from the group consisting of a hydroxyl group, an alkoxyl group having a carbon number less than 6, an amine group, a thiol group, a ester group, an alkene group, an alkyne group, an epoxy group, an aziridine group, an oxetane group, an aldehyde group, a ketone group, and a carboxylic acid group.
8. The method according to claim 6, wherein the cross-linker comprises at least one crosslinkable functional group, and the at least one crosslinkable functional group is selected from the group consisting of a hydroxyl group, an alkoxyl group having a carbon number less than 6, an amine group, a thiol group, a ester group, an alkene group, an alkyne group, an epoxy group, an aziridine group, an oxetane group, an aldehyde group, a ketone group, and a carboxylic acid group.
9. The method according to claim 6, wherein the at least one decomposable functional group of the cross-linker is selected from the group consisting of an ester group, an ether group, a silyl ether group, an acetal group, a ketal group, an amide group, an imine group, an imide group, and a carbamate group.
10. The method according to claim 6, wherein the curing process is performed at a temperature ranging between about 100° C. and 400° C.
11. The method according to claim 6, further comprising forming a middle layer between the under layer and the patterned photoresist layer.
12. The method according to claim 6, wherein in the step of decomposing the decomposable functional group, a bond in the at least one decomposable functional group is broken.
13. The method according to claim 6, wherein removing the under layer is performed under a condition of pH 4˜10.
14. The method according to claim 6, wherein removing the under layer is performed under a condition of pH 6-8.
15. A method of manufacturing a semiconductor device, comprising:
- forming an under layer over a dielectric layer, wherein the under layer comprises a crosslinked polymeric material comprising at least one decomposable functional group;
- forming a patterned photoresist layer over the under layer;
- performing a first etching process to transfer a pattern of the patterned photoresist layer to the under layer;
- by using the under layer as a mask, performing a second etching process to transfer the pattern to the dielectric layer; and
- removing the under layer by decrosslinking the crosslinked polymeric material through the at least one decomposable functional group.
16. The method according to claim 15, wherein the at least one decomposable functional group is selected from the group consisting of an ester group, an ether group, a silyl ether group, an acetal group, a ketal group, an amide group, an imine group, an imide group, and a carbamate group.
17. The method according to claim 15, wherein the under layer is formed directly on the dielectric layer.
18. The method according to claim 15, wherein the dielectric layer is a low-k dielectric layer.
19. The method according to claim 15, wherein removing the under layer is performed under a condition of pH 4˜10.
20. The method according to claim 15, wherein removing the under layer is performed under a condition of pH 6˜8.
21. A method of manufacturing a semiconductor device, comprising:
- forming a layer of an under layer composition, wherein the under layer composition comprises a polymeric material and a cross-linker, the polymeric material comprises at least one reaction group, the cross-linker comprises at least one crosslinkable functional group and at least one decomposable functional group, the at least one crosslinkable functional group is capable of crosslinking with the at least one reaction group of the polymeric material, and the decomposable functional group is capable of being decomposed under a condition of pH 4˜10;
- performing a curing process on the layer of the under layer composition to form an under layer, wherein the cross-linker is crosslinked with the polymeric material to form a crosslinked polymeric material having the at least one decomposable functional group;
- forming a patterned photoresist layer over the under layer;
- performing an etching process to transfer a pattern of the patterned photoresist layer to the under layer; and
- removing the under layer by decomposing the decomposable functional group.
22. The method according to claim 21, wherein the at least one reaction group of the polymeric material is selected from the group consisting of a hydroxyl group, an alkoxyl group having a carbon number less than 6, an amine group, a thiol group, a ester group, an alkene group, an alkyne group, an epoxy group, an aziridine group, an oxetane group, an aldehyde group, a ketone group, and a carboxylic acid group.
23. The method according to claim 21, wherein the at least one crosslinkable functional group of the cross-linker is selected from the group consisting of a hydroxyl group, an alkoxyl group having a carbon number less than 6, an amine group, a thiol group, a ester group, an alkene group, an alkyne group, an epoxy group, an aziridine group, an oxetane group, an aldehyde group, a ketone group, and a carboxylic acid group.
24. The method according to claim 21, wherein the at least one decomposable functional group of the cross-linker is selected from the group consisting of an ester group, an ether group, a silyl ether group, an acetal group, a ketal group, an amide group, an imine group, an imide group, and a carbamate group.
25. The method according to claim 21, wherein the decomposable functional group is capable of being decomposed under a condition of pH 6˜8.
Type: Application
Filed: Mar 24, 2017
Publication Date: Sep 27, 2018
Applicant: Taiwan Semiconductor Manufacturing Co., Ltd. (Hsinchu)
Inventors: Chen-Yu Liu (Kaohsiung City), Chin-Hsiang Lin (Hsin-Chu), Ching-Yu Chang (Yilang county), Ming-Hui Weng (New Taipei City)
Application Number: 15/468,109