This U.S. nonprovisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application 10-2016-0054792 filed on May 3, 2016, the entire contents of which are hereby incorporated by reference.
The present inventive concept relates to a semiconductor device and a method for manufacturing the semiconductor device and, more particularly, to a data storage device and a method for manufacturing the data storage device.
Semiconductor devices have an important role in the electronic industry because of the small size, multi-function and/or low fabrication cost of the semiconductor devices. Data storage semiconductor devices can store logic data. The semiconductor devices are increasingly integrated as the electronics industry has developed. The data storage devices have also been increasingly integrated and are being fabricated to have reduced line widths.
Additionally, high reliability has been demanded with the high integration of the data storage devices. However, the high integration may deteriorate the reliability of the data storage devices. Therefore, research is being conducted to enhance the reliability of the data storage devices.
Embodiments disclosed herein provide a data storage device and a method for manufacturing the same in which the data storage device can be easily fabricated.
Embodiments disclosed herein provide a data storage device and a method for manufacturing the same in which the data storage device has a superior reliability.
According to exemplary embodiments disclosed herein, a data storage device may comprise: a substrate including a cell region and a peripheral circuit region; a first conductive line on the peripheral circuit region of the substrate; a peripheral contact plug between the substrate and the first conductive line, the peripheral contact plug being in contact with the first conductive line; a second conductive line on the cell region of the substrate; a plurality of data storage structures between the substrate and the second conductive line, the plurality of data storage structures connecting to the second conductive line; and a wiring structure between the substrate and each of the data storage structures and between the substrate and the peripheral contact plug. The first conductive line may include a bottom surface having a position from the substrate that is lower than a position of a bottom surface of the second conductive line.
According to exemplary embodiments disclosed herein, a method for manufacturing a data storage device may comprise: providing a substrate including a cell region and a peripheral circuit region; forming a plurality of data storage structures on the cell region of the substrate; forming a mold layer that covers the data storage structures and extends onto the peripheral circuit region on the substrate; forming a mask layer that covers the cell region and the peripheral circuit region on the mold layer; forming a first opening in the mask layer, the first opening exposing the mold layer formed on the peripheral circuit region; etching the mold layer using the mask layer having the first opening as an etch mask to form a preliminary trench in the mold layer formed on the peripheral circuit region; forming a second opening in the mask layer, the second opening exposing the mold layer formed on the cell region; and etching the mold layer using the mask layer having the first and second openings as an etch mask to form a first trench extending from the preliminary trench toward the substrate and a second trench exposing the data storage structures.
According to exemplary embodiments disclosed herein, a data storage device may include a substrate comprising a cell region and a peripheral circuit region; a mold layer on the cell region and the peripheral circuit region; a first conductive line on the mold layer in the cell region in which a bottom surface of the first conductive line is at a first height above the substrate; a plurality of data storage structures in contact with the first conductive line in which the plurality of data storage structures are disposed between the substrate and the first conductive line; a second conductive line on the mold layer in the peripheral circuit region in which a bottom surface of the second conductive line is at a second height above the substrate and in which the second height is less that the first height; and a peripheral contact plug in contact with the second conductive line and being disposed between the substrate and the second conductive line.
According to exemplary embodiments disclosed herein, a method to form a data storage device may include: providing a substrate comprising a cell region and a peripheral circuit region; forming a mold layer on the cell region and the peripheral circuit region; forming a first conductive line on the mold layer in the cell region in which a bottom surface of the first conductive line is at a first height above the substrate; forming a plurality of data storage structures in contact with the first conductive line in which the plurality of data storage structures are disposed between the substrate and the first conductive line; forming a second conductive line on the mold layer in the peripheral circuit region in which a bottom surface of the second conductive line are at a second height above the substrate and in which the second height is less that the first height; and forming a peripheral contact plug in contact with the second conductive line and being disposed between the substrate and the second conductive line.
Referring to
A first interlayer dielectric layer 102 may be disposed on the substrate 100. The first interlayer dielectric layer 102 may cover selection devices (not shown) that are provided on the substrate 100. The selection devices may include field effect transistors or diodes. The first interlayer dielectric layer 102 may include an oxide, a nitride, and/or an oxynitride. The first interlayer dielectric layer 102 may include a wiring structure 110 that is provided in the first interlayer dielectric layer 102. The wiring structure 110 may include lines 104 that are spaced apart from the substrate 100 and contacts 106 that are connected to the lines 104. The lines 104 may be electrically connected to the substrate 100 through the contacts 106. The wiring structure 110 may further include lower lines (not shown) and lower contacts (not shown) that are connected to the lower lines. The lower lines may be disposed between the substrate 100 and the contacts 106, and the lower contacts may be disposed between the substrate 100 and the lower lines. The lines 104 may be connected to the lower lines through the contacts 106, and the lower lines may be electrically connected to the substrate 100 through the lower contacts. The lines 104 and the contacts 106 may include a metallic material. For example, the lines 104 and the contacts 106 may include copper (Cu). In some embodiments, the lines 104 may include top surfaces that are substantially coplanar with a top surface of the first interlayer dielectric layer 102.
A second interlayer dielectric layer 114 may be provided on the first interlayer dielectric layer 102. An intermediate layer 112 may be interposed between the first interlayer dielectric layer 102 and the second interlayer dielectric layer 114. The second interlayer dielectric layer 114 and the intermediate layer 112 may cover an entire surface of the substrate 100 and further cover the top surfaces of the lines 104. The second interlayer dielectric layer 114 may include an oxide, a nitride, and/or an oxynitride. The intermediate layer 112 may include a nitride. The intermediate layer 112 may include, for example, carbon containing silicon nitride.
A plurality of cell contact plugs 116 may be provided that penetrate the second interlayer dielectric layer 114 and the intermediate layer 112 on the cell region CR of the substrate 100. The cell contact plugs 116 may be configured to penetrate the second interlayer dielectric layer 114 and the intermediate layer 112 and thus be connected to the lines 104 of the wiring structure 110. Each of the cell contact plugs 116 may be connected to a corresponding one of the lines 104. Each of the cell contact plugs 116 may be in direct contact with a top surface of the corresponding one of the lines 104. The each of the cell contact plugs 116 may be electrically connected to a terminal of a corresponding one of the selection devices through a corresponding one of the lines 104. The cell contact plugs 116 may include a doped semiconductor material (e.g., doped silicon), a metal (e.g., tungsten, titanium, and/or tantalum), a conductive metal nitride (e.g., titanium nitride, tantalum nitride, and/or tungsten nitride), and/or a metal-semiconductor compound (e.g., metal silicide). In some embodiments, the cell contact plugs 116 may include top surfaces that are substantially coplanar with a top surface of the second interlayer dielectric layer 114.
A plurality of data storage structures 150 may be provided on the second interlayer dielectric layer 114. The data storage structures 150 may be provided on the cell region CR of the substrate 100 and, as viewed in the plan view of
A mold layer 118 may be provided on the second interlayer dielectric layer 114 and cover the data storage structures 150. The mold layer 118 may be provided on the cell region CR of the substrate 100 and cover sidewalls of the data storage structures 150. The mold layer 118 may extend onto the peripheral circuit region PR of the substrate 100 and be in contact with the second interlayer dielectric layer 114. The mold layer 118 may include an oxide, a nitride, and/or an oxynitride.
A first conductive line 180 may be provided in the mold layer 118 on the peripheral circuit region PR. In some embodiments, the first conductive line 180 may extend in substantially the first direction D1, but the present inventive concept is so limited and in some embodiments the first conductive line 180 may extend in a direction that is different from the first direction D1. A peripheral contact plug 170 may be provided between the first conductive line 180 and the substrate 100. The peripheral contact plug 170 may be provided between the first conductive line 180 and the wiring structure 110, and may be in contact with the first conductive line 180. The peripheral contact plug 170 may be configured to penetrate the mold layer 118, the second interlayer dielectric layer 114, and the intermediate layer 112 and thus be connected to a corresponding one of the lines 104 of the wiring structure 110. The peripheral contact plug 170 may be electrically connected to a terminal of a corresponding one of the selection devices (not shown) through the corresponding one of the lines 104. The first conductive line 180 may include a top surface 180U that is substantially coplanar with a top surface of the mold layer 118. The first conductive line 180 may include a first line pattern 164 and a first barrier pattern 166 that extends along sidewalls and a bottom surface of the first line pattern 164. An extending direction of the first line pattern 164 may be substantially the same as an extending direction of the first conductive line 180. The peripheral contact plug 170 may be in contact with the first line pattern 164 without an interface between the peripheral contact plug 170 and the first line pattern 164. For example, the peripheral contact plug 170 may extend from the bottom surface of the first line pattern 164 and may be integrally combined with the first line pattern 164 to form a single unitary body. The first barrier pattern 166 may extend from the bottom surface of the first line pattern 164 toward sidewalls and a bottom surface of the peripheral contact plug 170. The first barrier pattern 166 may be interposed between the first line pattern 164 and the mold layer 118, and between the peripheral contact plug 170 and the mold layer 118. The first barrier pattern 166 may extend between the peripheral contact plug 170 and the second interlayer dielectric layer 114 and between the peripheral contact plug 170 and the intermediate layer 112. The first barrier pattern 166 may be interposed between the bottom surface of the peripheral contact plug 170 and a corresponding line 104 that is connected to the peripheral contact plug 170. The first barrier pattern 166 may be in direct contact with a top surface of the corresponding line 104 that is connected to the peripheral contact plug 170. The first line pattern 164 and the peripheral contact plug 170 may include the same material. The first line pattern 164 and the peripheral contact plug 170 may include a metallic material (e.g., copper (Cu)). The first barrier pattern 166 may include a conductive metal nitride.
A second conductive line 182 may be provided in the mold layer 118 on the cell region CR. A plurality of the second conductive line 182 may be provided, and the plurality of second conductive lines 182 may extend substantially in the first direction D1 and may be spaced apart from each other in the second direction D2. The second conductive line 182 may be commonly connected to the data storage structures 150 that are arranged in the first direction D1. In some embodiments, the second conductive line 182 may be commonly in contact with the top surfaces of the data storage structures 150 that are arranged in the first direction D1. The second conductive line 182 may include a top surface 182U that is substantially coplanar with the top surface of the mold layer 118. The second conductive line 182 may include a second line pattern 160 and a second barrier pattern 162 that extends along sidewalls and a bottom surface of the second line pattern 160. The second barrier pattern 162 may be interposed between the second line pattern 160 and the mold layer 118, and between the second line pattern 160 and each of the data storage structures 150. The second line pattern 160 may include the same material as used to form the first line pattern 164 and the peripheral contact plug 170. The second line pattern 160 may include a metallic material (e.g., copper (Cu)). The second barrier pattern 162 may include the same material as used to form the first barrier pattern 166. The second barrier pattern 162 may include a conductive metal nitride.
The first conductive line 180 may include a bottom surface 180L that has a position with respect to the substrate 100 that is lower than a position of a bottom surface 182L of the second conductive line 182 with respect to the substrate 100. That is, the first conductive line 180 may include a bottom surface 180L that has a height above the substrate 100 that is lower than a height above the substrate 100 of a bottom surface 182L of the second conductive line 182. The top surface 180U of the first conductive line 180 may be positioned at substantially the same height from the substrate 100 as the top surface 182U of the second conductive line 182. Each of the first and second conductive lines 180 and 182 may function as a bit line.
Referring to
When the bottom surfaces 180L and 182L of the first and second conductive lines 180 and 182 are positioned at substantially the same height with respect to the substrate 100, an electrical connection between the first conductive line 180 and a corresponding line 104 may necessitate that the peripheral contact plug 170 should be formed to have a high aspect ratio or another contact (or pad) may be needed in addition to the peripheral contact plug 170.
According to the present inventive concept, the bottom surface 180L of the first conductive line 180 may be positioned to be lower than the bottom surface 182L of the second conductive line 182. That is, the bottom surface 180L of the first conductive line 180 may have a height above the substrate 100 that is lower than the bottom surface 182L of the second conductive line 182 above the substrate 100. It thus may be possible that the peripheral contact plug 170 may be formed to have a relatively low aspect ratio for the electrical connection between the first conductive line 180 and its corresponding line 104. In other words, it may be possible to easily form the peripheral contact plug 170 because the peripheral contact plug 170 has a relatively low aspect ratio. Furthermore, no additional contact (or pad) may be required for the electrical connection between the first conductive line 180 and its corresponding line 104. As a result, it may be advantageous to simplify the fabrication process of the data storage device and to prevent the occurrence of defects caused by the formation of the additional contact (or pad).
It may then be possible to easily fabricate the data storage device having superior reliability.
The data storage section 130 will be hereinafter discussed in detail with reference to
Referring to
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The data storage section 130 may include a magnetic tunnel junction MTJ having magnetic layers ML1 and ML2 that are spaced apart from each other and a tunnel barrier TBL between the magnetic layers ML1 and ML2. One of the magnetic layers ML1 and ML2 may be a reference layer having a magnetization direction that is fixed irrespective of an external magnetic field under a normal-use environment. The other one of the magnetic layers ML1 and ML2 may be free layer having a magnetization direction that is freely changed in response to an external magnetic field.
The magnetic tunnel junction MTJ may have an electrical resistance value that is much greater in a case in which the magnetization directions of the reference and free layers are antiparallel to each other than in a case in which the magnetization directions of the reference and free layers are parallel to each other. For example, the electrical resistance of the magnetic tunnel junction may be adjusted by changing the magnetization direction of the free layer. The data storage section 130 may then store data in the unit memory cell MC using the difference of the electrical resistance in accordance with the magnetization direction.
Referring to
An intermediate layer 112 and a second interlayer dielectric layer 114 may be sequentially stacked on the first interlayer dielectric layer 102. The second interlayer dielectric layer 114 may include an oxide, a nitride, and/or an oxynitride, and the intermediate layer 112 may include a nitride. The intermediate layer 112 may include, for example, carbon containing silicon nitride.
A plurality of cell contact plugs 116 may be formed to penetrate the second interlayer dielectric layer 114 and the intermediate layer 112 on the cell region CR of the substrate 100. The formation of the cell contact plugs 116 may include forming cell contact holes 116H to penetrate the second interlayer dielectric layer 114 and the intermediate layer 112, and then forming the cell contact plugs 116 in the respective cell contact holes 116H. Each of the cell contact holes 116H may expose a top surface of a corresponding one of the lines 104. Each of the cell contact plugs 116 may be electrically connected to a terminal of a corresponding one of the selection devices through a corresponding one of the lines 104. The cell contact plugs 116 may include a doped semiconductor material (e.g., doped silicon), a metal (e.g., tungsten, titanium, and/or tantalum), a conductive metal nitride (e.g., titanium nitride, tantalum nitride, and/or tungsten nitride), and/or a metal-semiconductor compound (e.g., metal silicide). The cell contact plugs 116 may have top surfaces that are substantially coplanar with a top surface of the second interlayer dielectric layer 114.
Referring to
A mold layer 118 may be formed on the second interlayer dielectric layer 114 and cover the data storage structures 150. The mold layer 118 may be provided on the cell region CR of the substrate 100 and cover sidewalls of the data storage structures 150, and may extend toward the peripheral circuit region PR of the substrate 100 and contact with the second interlayer dielectric layer 114. The mold layer 118 may include an oxide, a nitride, and/or an oxynitride. A mask layer 190 may be formed on the mold layer 118 and cover the cell region CR and the peripheral circuit region PR. The mask layer 190 may include a material having an etch selectivity with respect to the mold layer 118. For example, the mask layer 190 may include a conductive metal nitride (e.g., titanium nitride).
Referring to
Referring to
The mold layer 118 on the peripheral circuit region PR may be etched using the preliminary mask pattern 192 as an etch mask to form, in the mold layer 118, a preliminary hole 196 that extends from the bottom surface of the preliminary trench 194. The formation of the preliminary hole 196 may include etching the mold layer 118 that is exposed through the first preliminary opening 192a by performing an etch process that uses the preliminary mask pattern 192 as an etch mask and has an etch selectivity with respect to the mask layer 190. Therefore, the mask layer 190 exposed through the second preliminary opening 192b may not be removed on the cell region CR, but may remain on the mold layer 118 during the etch process to form the preliminary hole 196.
Referring to
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Referring back to
Through the planarization process, the first and second conductive lines 180 and 182 may respectively have top surfaces 180U and 182U positioned at substantially the same height from the substrate 100. The first trench 204 may have the bottom surface 204L having a position from the substrate 100 that is lower than a position of the bottom surface 208L of the second trench 208 so that the first conductive line 180 may have a bottom surface 180L having a position from the substrate 100 that is lower than a position of a bottom surface 182L of the second conductive line 182.
As shown in
According to the present inventive concept, the preliminary trench 194 and the preliminary hole 196 may be formed in the mold layer 118 on the peripheral circuit region PR. As viewed in a plan view, the preliminary trench 194 and the preliminary hole 196 may define regions where the first conductive line 180 and the peripheral contact plug 170 are formed. Thereafter, it may be possible to simultaneously form the first trench 204 that extends from the preliminary trench 194 toward the substrate 100, the peripheral contact hole 206 that extends from the preliminary hole 196 toward the substrate 100, and the second trench 208 that exposes the data storage structures 150 on the cell region CR. As the preliminary trench 194 and the preliminary hole 196 are formed in the mold layer 118 before the first trench 204 and the peripheral contact hole 206 are formed, the peripheral contact hole 206 may be formed to have a relatively low aspect ratio. It thus may be possible to easily form the peripheral contact hole 206, and it may not be necessary for any additional contact (or pad) for the electrical connection to be between the first conductive line 180 and a corresponding line 104. As a result, it may be advantageous to simplify the fabrication process of the data storage device and to prevent the occurrence of defects that may be caused by the formation of the additional contact (or pad).
It may then be possible to easily fabricate the data storage device having superior reliability.
According to the present inventive concept, the first conductive line may have the bottom surface having a position from the substrate that is lower than a position of the bottom surface of the second conductive line. Therefore, it may be possible that the peripheral contact plug is formed to have a relatively low aspect ratio for the electrical connection between the first conductive line and its underlying line. In addition, it may not be necessary for any additional contact (or pad) for the electrical connection between the first conductive line and the underlying line. As a result, it may be advantageous to simplify the fabrication process of the data storage device and to prevent the occurrence of defects that may be caused by the formation of an additional contact (or pad).
It therefore may be provided the data storage device and a method for fabricating the same having a superior reliability and easy fabrication.
Although the present invention has been described in connection with the embodiment of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope of the attached claims.
Number | Date | Country | Kind |
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10-2016-0054792 | May 2016 | KR | national |