The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs. Each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs.
In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling-down process generally provides benefits by increasing production efficiency and lowering associated costs.
However, since feature sizes continue to decrease, fabrication processes continue to become more difficult to perform. Therefore, it is a challenge to form reliable semiconductor devices at smaller and smaller sizes.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It should be noted that, in accordance with 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 subject matter provided. 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. It should be understood that additional operations can be provided before, during, and after the method, and some of the operations described can be replaced or eliminated for other embodiments of the method.
In some embodiments, the substrate 110 is made of an elementary semiconductor material including silicon or germanium in a single crystal, polycrystal, or amorphous structure. In some other embodiments, the substrate 110 is made of a compound semiconductor, such as silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, an alloy semiconductor, such as SiGe, or GaAsP, or combinations thereof. The substrate 110 may also include multi-layer semiconductors, semiconductor on insulator (SOI) (such as silicon on insulator or germanium on insulator), or combinations thereof.
As shown in
The isolation structure 120 is made of a dielectric material, in accordance with some embodiments. The dielectric material includes silicon oxide, silicon nitride, silicon oxynitride, fluoride-doped silicate glass (FSG), a low-K dielectric material, other suitable materials, or combinations thereof, in accordance with some embodiments. The isolation structure 120 is formed by using an isolation technology, such as local oxidation of semiconductor (LOCOS), shallow trench isolation (STI), or the like, in accordance with some embodiments.
In some embodiments, the formation of the isolation structure 120 includes patterning the substrate 110 by a photolithography process, etching a trench in the substrate 110 (for example, by using a dry etching, wet etching, or plasma etching process, or a combination thereof), and filling the trench (for example, by using a chemical vapor deposition process) with the dielectric material. In some embodiments, the filled trench may have a multi-layer structure, such as a thermal oxide liner layer filled with silicon nitride or silicon oxide.
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
The protection layer 180 is further formed over sidewalls 164 of the anti-reflection layer 160, in accordance with some embodiments. The protection layer 180 includes a polymer material, in accordance with some embodiments. In some embodiments, the protection layer 180 continuously covers the sidewalls 164 and 172.
The protection layer 180 surrounds the mask layer 170 and the anti-reflection layer 160, in accordance with some embodiments. The protection layer 180 continuously surrounds the mask layer 170 and the anti-reflection layer 160, in accordance with some embodiments. After the plasma etching and deposition process, the anti-reflection layer 160 and the protection layer 180 expose a portion 152 of the film 150, in accordance with some embodiments.
In some embodiments, the plasma etching and deposition process uses a processing gas. The processing gas is configured to be an etching gas and a polymer gas, in accordance with some embodiments. The polymer gas is configured to provide a polymer deposition during the plasma etching and deposition process, in accordance with some embodiments.
The processing gas includes CHF3, CH2F2, CH3F, or a combination thereof. The processing gas includes pure CHF3 and unavoidable impurity gas(es), in accordance with some embodiments. The processing gas includes pure CH2F2 and unavoidable impurity gas(es), in accordance with some embodiments. The processing gas includes pure CH3F and unavoidable impurity gas(es), in accordance with some embodiments.
During the plasma etching and deposition process, an exposed portion of the mask layer 170 may be etched away. Since the protection layer 180 is formed over sidewalls 172 of the mask layer 170 during the plasma etching and deposition process, the protection layer 180 reduces the etching rate of the mask layer 170 adjacent to the sidewalls 172.
Therefore, the mask layer 170, which has been etched, is able to maintain the desired width W1, which is greater than that of the mask layer, which has been etched without the protection layer 180. Furthermore, the protection layer 180 over the sidewalls 172 may be an etching mask during the removal of the portion 162 of the anti-reflection layer 160.
As a result, the width W2 of the anti-reflection layer 160, which has been etched, is enlarged by the formation of the protection layer 180. Therefore, the anti-reflection layer 160, which has been etched, is able to have the desired width W2. The formation of the protection layer 180 prevents the critical dimension (e.g., the width W2) of the anti-reflection layer 160 from undesirable shrinkage. The formation of the protection layer 180 simplifies the design of the photomask used in the photolithography process of
In some embodiments, the sidewalls 164 of the anti-reflection layer 160 are taper sidewalls. Therefore, the width W2 of the anti-reflection layer 160 increases toward the film 150, in accordance with some embodiments. As a result, the width W2 of the anti-reflection layer 160 is greater than the width W1 of the mask layer 170, in accordance with some embodiments. In some embodiments, the greatest width W2 of the anti-reflection layer 160 is greater than the width W1 of the mask layer 170.
The plasma etching and deposition process is performed using a bias power ranging from about 200 W to about 700 W, in accordance with some embodiments. The plasma etching and deposition process is performed at a pressure ranging from about 3 mTorr to about 10 mTorr, in accordance with some embodiments.
If the bias power is less than 200 W and the pressure is greater than 10 mTorr, the protection layer 180 may be not only formed over the sidewalls 164 and 172, but also formed over a top surface 154 of the portion 152, which hinders the removal process for removing the portion 152 of the film 150 performed subsequently. If the bias power is greater than 700 W and/or the pressure is less than 3 mTorr, the protection layer 180 is not formed or only partially-formed.
As shown in
After the removal process, since the mask layer 170 and the anti-reflection layer 160 have the desired widths W1 and W2, the film 150 has the desired width W3. In some embodiments, the protection layer 180 enlarges the width W3. The formation of the protection layer 180 prevents the critical dimensions (e.g., the widths W2 and W3) of the anti-reflection layer 160 and the film 150 from undesirable shrinkage.
As shown in
After the removal process for removing the portion 142, the remaining portion of the gate material layer 140a forms a gate 140, in accordance with some embodiments. The removal process also removes a portion of the gate dielectric layer 130 under the portion 142, in accordance with some embodiments. The removal process includes a dry etching process, in accordance with some embodiments.
After the removal process, since the film 150 have the desired width W3, the gate 140 has the desired width W4, in accordance with some embodiments. As shown in
As shown in
As shown in
As shown in
The heavily doped regions 114 are a heavily doped source region and a heavily doped drain region, in accordance with some embodiments. The heavily doped regions 114 are located at the two opposite sides of the gate 140, in accordance with some embodiments.
If the thickness of the protection layer 180 is greater than the desired thickness, the protection layer 180 may be thinned or removed. The detailed description is exemplary described as follows.
As shown in
After the removal process, since the mask layer 170 and the anti-reflection layer 160 have the desired widths W1 and W2, the film 150 has the desired width W3. As shown in
As shown in
After the removal process for removing the portion 142, the remaining portion of the gate material layer 140a forms a gate 140, in accordance with some embodiments. The removal process also removes a portion of the gate dielectric layer 130 under the portion 142, in accordance with some embodiments. The removal process includes a dry etching process, in accordance with some embodiments.
After the removal process, since the film 150 have the desired width W3, the gate 140 has the desired width W4, in accordance with some embodiments. As shown in
As shown in
As shown in
As shown in
The heavily doped regions 114 are a heavily doped source region and a heavily doped drain region, in accordance with some embodiments. The heavily doped regions 114 are located at the two opposite sides of the gate 140, in accordance with some embodiments.
After the step of
After the plasma etching and deposition process, the anti-reflection layer 160 has a portion 166 under the mask layer 170, in accordance with some embodiments. The portion 166 protrudes from an upper surface 168 of the portion 162 that is thinned out, in accordance with some embodiments. The portion 166 has sidewalls 164, in accordance with some embodiments.
The protection layer 180 is formed further over the sidewalls 164 of the portion 166, in accordance with some embodiments. The protection layer 180 covers the sidewalls 164 of the portion 166, in accordance with some embodiments. The protection layer 180 includes a polymer material, in accordance with some embodiments. In some embodiments, the protection layer 180 continuously covers the sidewalls 164 and 172. The protection layer 180 surrounds the mask layer 170 and the portion 166, in accordance with some embodiments. The protection layer 180 continuously surrounds the mask layer 170 and the portion 166, in accordance with some embodiments.
In some embodiments, the plasma etching and deposition process uses a processing gas. The processing gas is configured to be an etching gas and a polymer gas, in accordance with some embodiments. The polymer gas is configured to provide a polymer deposition during the plasma etching and deposition process, in accordance with some embodiments.
The processing gas includes CHF3, CH2F2, CH3F, or a combination thereof. The processing gas includes pure CHF3 and unavoidable impurity gas(es), in accordance with some embodiments. The processing gas includes pure CH2F2 and unavoidable impurity gas(es), in accordance with some embodiments. The processing gas includes pure CH3F and unavoidable impurity gas(es), in accordance with some embodiments.
As shown in
As shown in
After the removal process, since the mask layer 170 and the anti-reflection layer 160 have the desired widths W1 and W2, the film 150 has the desired width W3. As shown in
As shown in
After the removal process for removing the portion 142, the remaining portion of the gate material layer 140a forms a gate 140, in accordance with some embodiments. The removal process also removes a portion of the gate dielectric layer 130 under the portion 142, in accordance with some embodiments. The removal process includes a dry etching process, in accordance with some embodiments.
After the removal process, since the film 150 have the desired width W3, the gate 140 has the desired width W4, in accordance with some embodiments. As shown in
As shown in
As shown in
As shown in
The heavily doped regions 114 are a heavily doped source region and a heavily doped drain region, in accordance with some embodiments. The heavily doped regions 114 are located at the two opposite sides of the gate 140, in accordance with some embodiments.
In accordance with some embodiments, methods for forming semiconductor device structures are provided. The methods (for forming the semiconductor device structure) perform a plasma etching and deposition process to remove a portion of a first mask layer exposed by a second mask layer and to form a protection layer over a sidewall of the second mask layer. The protection layer is able to substantially maintain a critical dimension of the second mask layer during the plasma etching and deposition process. Therefore, the first mask layer, which has been etched, has a desired critical dimension. As a result, the methods improve the process yield.
In accordance with some embodiments, a method for forming a semiconductor device structure is provided. The method includes forming a film over a substrate. The method includes forming a first mask layer over the film. The method includes forming a second mask layer over the first mask layer. The second mask layer exposes a first portion of the first mask layer. The method includes performing a plasma etching and deposition process to remove the first portion of the first mask layer and to form a protection layer over a first sidewall of the second mask layer. The first mask layer exposes a second portion of the film after the plasma etching and deposition process. The method includes removing the second portion using the first mask layer and the second mask layer as an etching mask.
In accordance with some embodiments, a method for forming a semiconductor device structure is provided. The method includes forming a film over a substrate. The method includes forming a first mask layer over the film. The method includes forming a second mask layer over the first mask layer. The second mask layer exposes a first portion of the first mask layer. The method includes performing a plasma etching and deposition process to remove the first portion of the first mask layer and to form a protection layer over a first sidewall of the second mask layer. The first mask layer exposes a second portion of the film after the plasma etching and deposition process. The method includes removing the protection layer. The method includes removing the second portion of the film using the first mask layer and the second mask layer as an etching mask.
In accordance with some embodiments, a method for forming a semiconductor device structure is provided. The method includes forming a film over a substrate. The method includes forming a first mask layer over the film. The method includes forming a second mask layer over the first mask layer. The second mask layer exposes a first portion of the first mask layer. The method includes performing a plasma etching and deposition process to thin out the first portion of the first mask layer and to form a protection layer over a first sidewall of the second mask layer. The method includes removing the protection layer and the first portion of the first mask layer. The first mask layer exposes a second portion of the film after the removal of the first portion of the first mask layer. The method includes removing the second portion of the film using the first mask layer and the second mask layer as an etching mask.
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.
This application is a continuation application of U.S. application Ser. No. 15/444,039, filed Feb. 27, 2017, now U.S. Pat. No. 10,163,646, which is a continuation application of U.S. application Ser. No. 14/871,256, filed Sep. 30, 2015, now U.S. Pat. No. 9,583,356, the entirety of each are hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
5866448 | Pradeep | Feb 1999 | A |
5994226 | Kadomura | Nov 1999 | A |
6258726 | Park et al. | Jul 2001 | B1 |
6774044 | Ke et al. | Aug 2004 | B2 |
6955964 | Haselden et al. | Oct 2005 | B2 |
7858270 | Stamper et al. | Dec 2010 | B2 |
8294207 | Cho et al. | Oct 2012 | B2 |
10163646 | Liao | Dec 2018 | B2 |
20080292973 | Stamper | Nov 2008 | A1 |
20090206403 | Wang et al. | Aug 2009 | A1 |
20150318287 | Sugino | Nov 2015 | A1 |
Number | Date | Country | |
---|---|---|---|
20190115222 A1 | Apr 2019 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 15444039 | Feb 2017 | US |
Child | 16219835 | US | |
Parent | 14871256 | Sep 2015 | US |
Child | 15444039 | US |