Embodiments described herein relate to a semiconductor device and a method of manufacturing the same.
In recent years, fine patterns of a semiconductor device are often formed by sidewall transfer process. For example, word lines of a semiconductor storage device such as a NAND memory are formed by the sidewall transfer process for downscaling purposes in many cases. However, when the word lines are formed by the sidewall transfer process, the reduction of the line width and the space width of the word lines makes it difficult to form pad portions (hook-up portions), which are used to dispose contact plugs on the word lines. The reason is that the reduction of these widths makes it difficult, when lithography for processing the pad portions is performed, to perform the alignment in lithography for dividing the pad portions and cutting the word lines from the pad portions. Therefore, a method that can process the pad portions simply and accurately is demanded.
Embodiments will now be explained with reference to the accompanying drawings.
In one embodiment, a semiconductor device includes a substrate, first and second interconnects provided on the substrate so as to be apart from each other, and third and fourth interconnects provided on the substrate so as to be apart from each other. The device further includes a first pad portion connected with the first or third interconnect, and a second pad portion connected with the second or fourth interconnect, and provided so as to be apart from the first pad portion. The device further includes one or more fifth interconnects including an interconnect provided between the first interconnect and the second interconnect, and provided between at least one of the first and second pad portions and the first interconnect, and one or more sixth interconnects including an interconnect provided between the third interconnect and the fourth interconnect, and provided between at least one of the first and second pad portions and the third interconnect.
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First, a gate insulator 2, a. floating gate material 3, an inter gate insulator 4, a control gate material 5 that is an example of the interconnect layer, a first mask layer 11, a second mask layer 12, a hard mask layer 13 that is an example of the first film, a core material 14 that is an example of the second film, and a resist film 15 are formed in order, on a substrate 1 (
Examples of the substrate 1 include a semiconductor substrate such as a silicon substrate.
In this specification, the +Z direction is handled as the upward direction, and the −Z direction is handled as the downward direction. For example, the positional relation between the substrate 1 and the resist film 15 is described as the substrate 1 being positioned below the resist film 15. The −Z direction in the present embodiment may agree with the gravity direction, or may disagree with the gravity direction.
Examples of the gate insulator 2 include a silicon oxide film. Examples of the floating gate material 3 include a polysilicon layer. Examples of the inter gate insulator 4 include a silicon oxide film, a silicon nitride film, and a laminated film including them. Examples of the control gate material 5 include a polysilicon layer, a metal layer, and a laminated film including them.
Examples of the first mask layer 11 include an insulator such as a silicon nitride film. Examples of the second mask layer 12 include a silicon oxide film. Examples of the hard mask layer 13 include a polysilicon layer and an amorphous silicon layer. Examples of the core material 14 include a silicon oxide film.
Next, the resist film 15 is processed by lithography (
The belt portion 15A extends in the X direction, and surrounds one or more opening portions PA1 and one or more opening portions PA2. The belt portion 15B extends in the X direction, and surrounds one or more opening portions PB1 and one or more opening portions PB2. The line portions 15C1, 15C2 extend in the Y direction, and are connected with the belt portion 15A. The line portions 15D1, 15D2 extend in the Y direction, and are connected with the belt portion 15B. The opening portions PA1, PA2 are positioned near end portions of the line portions 15C1, 15C2, respectively. The opening portions PB1, PB2 are positioned near end portions of the line portions 15D1, 15D2, respectively.
The resist pattern further includes multiple belt portions having the same shape as the belt portions 15A, 15B, and multiple line portions having the same shape as the line portions 15C1, 15C2, 15D1, 15D2, but the illustration of these is omitted in
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Next, by the etching using the resist film 15 as a mask, the core material 14 is processed (
The belt portion 14A extends in the X direction, and surrounds one or more opening portions QA1 and one or more opening portions QA2. The belt portion 14B extends in the X direction, and surrounds one or more opening portions QB1 and one or more opening portions QB2. The line portions 14C1, 14C2 extend in the Y direction, and are connected with the belt portion 14A. The line portions 14D1, 14D2 extend in the Y direction, and are connected with the belt portion 14B. The opening portions QA1, QA2 are positioned near end portions of the line portions 14C1, 14C2, respectively. The opening portions QB1, QB2 are positioned near end portions of the line portions 14D1, 14D2, respectively.
The belt portion 14A, the line portions 14C1, 14C2 and the opening portions QA1, QA2 are examples of the first belt portion, the first and second line portions and the first and second opening portions, respectively. Similarly, the belt portion 14B, the line portions 14D1, 14D2 and the opening portions QB1, QB2 are examples of the first belt portion, the first and second line portions and the first and second opening portions, respectively.
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Next, a first sidewall film 16 is formed on the side faces of the core material 14 (
The first sidewall film 16 includes line portions 16C1, 16C2 formed on the side faces of the belt portion 14A and the line portion 14C1, line portions 16C3, 16C4 formed on the side faces of the belt portion 14A and the line portion 14C2, line portions 16D1, 16D2 formed on the side faces of the belt portion 14B and the line portion 14D1, and line portions 16D3, 16D4 formed on the side faces of the belt portion 14B and the line portion 14D2.
The first sidewall film 16 further includes dummy portions 16E1, 16E2 formed on the side faces of the opening portions QA1, QA2 respectively, and dummy portions 16F1, 16F2 formed on the side faces of the opening portions QB1, QB2 respectively. The dummy portions 16E1, 16E2, 16F1, 16F2 have a ring shape.
On the side faces of the belt portion 14A, the line portions 16C1, 16C2 are connected with the line portions 16C3, 16C4, respectively. Further, on the side faces of the belt portion 14B, the line portions 16D1, 16D2 are connected with the line portions 16D3, 16D4, respectively.
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Next, the core material 14 is removed by etching or ashing (
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Next, by the etching using the first sidewall film 16 as a mask, the hard mask layer 13 is processed (
The belt portions 13A, 13B extend in the X direction. The line portions 13C1 to 13C4, 13D1 to 13D4 extend mainly in the Y direction. The line portions 13C1 to 13C4 are connected with the belt portion 13A, and the line portions 13D1 to 13D4 are connected with the belt portion 13B. The dummy portions 13E1 are positioned between the line portion 13C1 and the line portion 13C2, and the dummy portions 13E2 are positioned between the line portion 13C3 and the line portion 13C4. The dummy portions 13F1 are positioned between the line portion 13D1 and the line portion 13D2, and the dummy portions 13F2 are positioned between the line portion 13D3 and the line portion 13D4.
The line portions 16C1 to 16C4, 16D1 to 16D4 and dummy portions 16E1, 16E2, 16F1, 16F2 of the first sidewall film 16 are transferred to the hard mask layer 13, and thereby, the line portions 13C1 to 13C4, 13D1 to 13D4 and dummy portions 13E1, 13E2, 13F1, 13F2 in the present embodiment are formed.
On the other hand, the belt portions 13A, 13B in the present embodiment are formed by the reverse loading effect. The reverse loading effect accelerates the etching rate for narrow space patterns, and decelerates the etching rate for wide space patterns.
The reason is that the narrow space patterns are largely affected by the etching, compared to the wide space patterns.
In the present embodiment, the space between the line portions 16C1, 16C2 and the space between the line portions 16C3, 16C4 are wide at a region between the dummy portions 16E1, 16E2. Therefore, in the steps of
Similarly, the space between the line portions 13D1, 13D2 and the space between the line portions 13D3, 13D4 are wide at a region between the dummy portions 13F1, 13F2. Therefore, in the steps of
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Next, by the etching using the hard mask layer 13 as a mask, the second mask layer 12, the first mask layer 11, the control gate material 5, the inter gate insulator 4, the floating gate material 3, and the gate insulator 2 are processed (
The same goes for the control gate material 5, the inter gate insulator 4, the floating gate material 3, and the gate insulator 2. For example, the control gate material 5 is processed into an interconnect pattern including belt portions 5A, 5B, line portions 5C1 to 5C4, 5D1 to 5D4, and dummy portions 5E1, 5E2, 5F1, 5F2.
The belt portions 5A, 5B, the line portions 5C1 to 5C4, 5D1 to 5D4, and the dummy portions 5E1, 5E2, 5F1, 5F2, for which the illustration of the reference characters and the shapes is omitted for the convenience of the figure drawing, are positioned under the belt portions 11A, 11B, the line portions 11C1 to 11C4, 11D1 to 11D4 and the dummy portions 11E1, 11E2, 11F1, 11F2, respectively. The line portions 5C1, 5C2, 5D1, 5D2, 5D4, 5D3, 5C4, 5C3 function as word lines WL1 to WL8, respectively.
The belt portions 11A, 11B extend in the X direction. The line portions 11C1, 11C2, 11D1, 11D2 extend mainly in the Y direction, and are arranged so as to be close to and apart from each other. The line portions 11C3, 11C4, 11D3, 11D4 extend mainly in the Y direction, and are arranged so as to be close to and apart from each other. The line portions 11C1 to 11C4 are connected with the belt portion 11A, and the line portions 11D1 to 11D4 are connected with the belt portion 11B. The same goes for the belt portions 5A, 5B, and the line portions 5C1 to 5C4, 5D1 to 5D4.
The dummy portions 11E1 are positioned between the line portion 11C1 and the line portion 11C2, and are positioned between the belt portion 11A and the line portion 11C1. The dummy portions 11E2 are positioned between the line portion 11C3 and the line portion 11C4, and are positioned between the belt portion 11A and the line portion 11C3. The dummy portions 11E1, 11E2 have a ring shape. The same goes for the belt portion 5A, the line portions 5C1 to 5C4 and the dummy portions 5E1, 5E2. The belt portion 5A is an example of the first belt portion. The line portions 5C1 to 5C4 are examples of the first to fourth interconnects, respectively. The dummy portions 5E1, 5E2 are examples of the one or more fifth interconnects and the one or more sixth interconnects, respectively.
The dummy portions 11F1 are positioned between the line portion 11D1 and the line portion 11D2, and are positioned between the belt portion 11B and the line portion 11D1. The dummy portions 11F2 are positioned between the line portion 11D3 and the line portion 11D4, and are positioned between the belt portion 11B and the line portion 11D3. The dummy portions 11F1, 11F2 have a ring shape. The same goes for the belt portion 5B, the line portions 5D1 to 5D4 and the dummy portions 5F1, 5F2. The belt portion 5B is an example of the first belt portion. The line portions 5D1 to 5D4 are examples of the first to fourth interconnects, respectively. The dummy portions 5F1, 5F2 are examples of the one or more fifth interconnects and the one or more sixth interconnects, respectively.
Similarly to the belt portion 13A, the belt portion 11A in the present embodiment is formed such that opening portions SA1, SA2 remain at corner portions of the belt portion 11A. The belt portion 11A is connected with one dummy portion 5E1, between the opening portions SA1, and is connected with one dummy portion 5E2, between the opening portions SA2. The same goes for the belt portion 11B and the line portions 11D1 to 11D4. Further, the same goes for the belt portions 5A, 5B and the line portions 5C1 to 5C4, 5D1 to 5D4.
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Next, a resist film not shown in the figure is formed on the substrate 1, and the resist film is processed by lithography. As a result, the resist film is processed into a resist pattern including trenches TA, TB, TC for processing (dividing) the belt portions 11A, 11B (
The trench TA extends in the X direction so as to divide the belt portion 11A into two. The trench TA further extends in the X direction so as to divide the dummy portions 11E1, 11E2 connected with the belt portion 11A, into two. The trench TB extends in the X direction so as to divide the belt portion 11B into two. The trench TB further extends in the X direction so as to divide the dummy portions 11F1, 11F2 connected with the belt portion 11B, into two. The trench TC extends mainly in the Y direction such that the belt portions 11A, 11B are disconnected from the line portions 11C3, 11C4, 11D3, 11D4. The trench TC is connected with the trenches TA, TB.
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Next, by the etching using the above resist film as a mask, the belt portions 11A, 11B are processed (
As a result, the belt portion 11A is processed into a belt portion 11A1 connected with the line portion 11C1 and separated from the line portion 11C3, and a belt portion 11A2 connected with the line portion 11C2 and separated from the line portion 11C4. The belt portions 11A1, 11A2 extend in the X direction, and are arranged so as to be close to and apart from each other in the Y direction. Each of the dummy portions 11E1 is positioned between the line portion 11C1 and the belt portion 11A1 and/or 11A2, and each of the dummy portions 11F1 is positioned between the line portion 11C3 and the belt portion 11A1 and/or 11A2.
Similarly to the belt portion 11A, the belt portion 5A is processed into a belt portion 5A1 connected with the line portion 5C1 and separated (electrically insulated) from the line portion 5C3, and a belt portion 5A2 connected with the line portion 5C2 and separated (electrically insulated) from the line portion 5C4. The belt portions 5A1, 5A2 function as pad portions (hook-up portions) HU1, HU2 for the word lines WL1, WL2, respectively.
The same goes for the belt portion 11B and the belt portion 5B. Similarly to the belt portion 11B, the belt portion 5B is processed into a belt portion 5B1 connected with the line portion 5D1 and separated (electrically insulated) from the line portion 5D3, and a belt portion 5B2 connected with the line portion 5D2 and separated (electrically insulated) from the line portion 5D4. The belt portions 5B1, 5B2 function as pad portions HU3, HU4 for the word lines WL3, WL4, respectively.
Thereafter, in the present embodiment, an inter layer dielectric is formed on the whole surface of the substrate 1, contact holes that penetrate the inter layer dielectric and reach the pad portions HU1 to HU4 are formed, and contact plugs 21 are formed on the pad portions HU1 to HU4 in the contact holes. Furthermore, various interconnect layers, plug layers, inter layer dielectrics and the like are formed on the substrate 1. In this way, the semiconductor device of the present embodiment is manufactured.
In the case where the initial space width is “Wa” or less, the final space width changes so as to be roughly proportional to the initial space width. For example, in the case where the initial space width is “Wa”, the final space width is “Wa”, which is close to “Wa”. Therefore, in the case where the initial space width is “Wa” or less, the shape of the patterns of the lower layer is roughly equal to the shape of the patterns of the upper layer.
However, when the initial space width increases to a range of “Wa” to “Wb”, the change rate of the final space width decreases from a positive value to about 0, and further changes to a negative value. Further, in the case where the initial space width is “Wb” or more, the final space width is 0. Therefore, in the case where the initial space width is “Wb” or more, the patterns of the upper layer are not transferred to the lower layer.
Therefore, in the present embodiment, the space width between the line portions 16C1, 16C2, 16D1, 16D2 and the space widths between the line portions 16C3, 16C4, 16D3, 16D4 are set to “Wa” or less. As a result, the patterns of the line portions 16C1, 16C2, 16D1, 16D2 and the patterns of the line portions 16C3, 16C4, 16D3, 16D4 are transferred to the hard mask layer 13, as shown in
Further, in the present embodiment, the space between the line portions 16C1, 16C2 and the space between the line portions 16C3, 16C4 are set to a width of “Wb” or more, at the region between the dummy portions 16E1, 16E2. As a result, the belt portion 13A is formed by the reverse loading effect, as shown in
Further, in the present embodiment, the dummy portions 16E1 are formed between the line portions 16C1, 16C2, and the dummy portions 16E2 are formed between the line portions 16C3, 16C4. As a result, spaces such as the opening portions RA1, RA2 remain near the belt portion 13A and the dummy portions 16E1, 16E2, as shown in
Therefore, according to the present embodiment, by using these spaces, the trenches TA, TB, TC are easily formed in the belt portions 11A, 11B, and the belt portions 11A, 11B are easily processed.
The trenches TA, TB in the present embodiment, which are formed such that some of the dummy portions 11E1, 11E2, 11F1, 11F2 are divided, may be formed such that all the dummy portions 11E1, 11E2, 11F1, 11F2 are divided, or may be formed such that the dummy portions 11E1, 11E2, 11F1, 11F2 are not divided.
Further, the trench TC in the present embodiment, which is formed at a position deviated from the belt portions 11A, 11B, may be formed in the belt portions 11A, 11B.
In the present embodiment, as shown in
Therefore, according to the present embodiment, it is possible to form the pad portions HU1 to HU4 from the belt portions 5A, 5B, simply and accurately. For example, it is possible to form a wide space in the ±X directions from the belt portions 11A, 11B (5A, 5B), and therefore, it is easy to avoid a mistaken cut of the word lines WL1 to WL4 by the trenches TA, TB.
Further, in the present embodiment, it is possible to form the belt portions 5A, 5B and the pad portions HU1 to HU4 in a nearly quadrangular shape. Therefore, according to the present embodiment, it is possible to set a wide area for the pad portions HU1 to HU4, and to enhance the integration degree of the semiconductor device.
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The dummy portions 16E1, 16E2 in
On the other hand, dummy portions 16E1, 16E2 in
In this way, it is possible to arbitrarily set the direction in which the dummy portions 16E1, 16E2 extend, the number of the dummy portion 16E1, and the number of the dummy portion 16E2.
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Dummy portions 16E1, 16E2 in
Dummy portions 13E1, 13E2 in
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Dummy portions 16E1, 16E2 in
As described above, it is possible to variously set the shape, number and arrangement of the dummy portions 16E1, 16E2 in the present embodiment. The same goes for the dummy portions in the other layers.
First, the gate insulator 2, the floating gate material 3, the inter gate insulator 4, the control gate material 5, the first mask layer 11, the second mask layer 12, the hard mask layer 13, the core material 14, and the resist film 15 are formed in order, on the substrate 1, and the resist film 15 is processed by lithography (see
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Next, by the etching using the resist film 15 as a mask, the core material 14 is processed (
The belt portions 14A1, 14A2 extend in the X direction, are arranged so as to be close to and apart from each other in the X direction, and surround one or more opening portions QA1 and one or more opening portions QA2, respectively. The belt portions 14B1, 14B2 extend in the X direction, are arranged so as to be close to and apart from each other in the X direction, and surround one or more opening portions QB1 and one or more opening portions QB2, respectively. The line portions 14C1, 14C2, 14D1, 14D2 extend in the Y direction, and are connected with the belt portions 14A1, 14A2, 14B1, 14B2, respectively. The opening portions QA1, QA2, QB1, QB2 are positioned near end portions of the line portions 14C1, 14C2, 14D1, 14D2, respectively.
The belt portions 14A1, 14A2, the line portions 14C1, 14C2, and the opening portions QA1, QA2 are examples of the first and second belt portions, the first and second line portions, and the first and second opening portions, respectively. Similarly, the belt portions 14B1, 14B2, the line portions 14D1, 14D2, and the opening portions QB1, QB2 are examples of the first and second belt portions, the first and second line portions, and the first and second opening portions, respectively.
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Next, a first sidewall film 16 is formed on the side faces of the core material 14, and the core material 14 is removed by etching or ashing (
The first sidewall film 16 includes line portions 16C1, 16C2 formed on the side faces of the belt portion 14A1 and the line portion 14C1, line portions 16C3, 16C4 formed on the side faces of the belt portion 14A2 and the line portion 14C2, line portions 16D1, 16D2 formed on the side faces of the belt portion 14B1 and the line portion 14D1, and line portions 16D3, 16D4 formed on the side faces of the belt portion 14B2 and the line portion 14D2.
The first sidewall film 16 further includes dummy portions 16E1, 16E2 formed on the side faces of the opening portions QA1, QA2 respectively, and dummy portions 16F1, 16F2 formed on the side faces of the opening portions QB1, QB2 respectively.
The line portions 16C1, 16C2 are connected with each other at the region where the belt portion 14A1 was present, and the line portions 16C3, 16C4 are connected with each other at the region where the belt portion 14A2 was present. Further, the line portions 16D1, 16D2 are connected with each other at the region where the belt portion 14B1 was present, and the line portions 16D3, 16D4 are connected with each other at the region where the belt portion 14B2 was present.
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Next, by the etching using the first sidewall film 16 as a mask, the hard mask layer 13 is processed, and the second mask layer 12, the first mask layer 11, the control gate material 5, the inter gate insulator 4, the floating gate material 3 and the gate insulator 2 are processed by the etching using the hard mask layer 13 as a mask (
The same goes for the control gate material 5, the inter gate insulator 4, the floating gate material 3, and the gate insulator 2. For example, the control gate material 5 is processed into an interconnect pattern including belt portions 5A1, 5A2, 5B1, 5B2, line portions 5C1 to 5C4, 5D1 to 5D4, and dummy portions 5E1, 5E2, 5F1, 5F2.
The belt portions 5A1, 5A2, 5B1, 5B2, the line portions 5C1 to 5C4, 5D1 to 5D4, and the dummy portions 5E1, 5E2, 5F1, 5F2, for which the illustration of the reference characters and the shapes is omitted for the convenience of the figure drawing, are positioned under the belt portions 11A1, 11A2, 11B1, 11B2, the line portions 11C1 to 11C4, 11D1 to 11D4, and the dummy portions 11E1, 11E2, 11F1, 11F2, respectively. The line portions 5C1, 5C2, 5D1, 5D2, 5D4, 5D3, 5C4, 5C3 function as word lines WL1 to WL8, respectively.
The line portions 11C1, 11C2 are connected with the belt portion 11A1, and the line portions 11C3, 11C4 are connected with the belt portion 11A2. The belt portions 11A1, 11A2 are arranged so as to be close to and apart from each other in the X direction. The line portions 11D1, 11D2 are connected with the belt portion 11B1, and the line portions 11D3, 11D4 are connected with the belt portion 11B2. The belt portions 11B1, 11B2 are arranged so as to be close to and apart from each other in the X direction. The same goes for the belt portions 5A1, 5A2, 5B1, 5B2, and the line portions 5C1 to 5C4, 5D1 to 5D4.
The dummy portions 11E1 are positioned between the belt portion 11A1 and the line portion 11C1, and the dummy portions 11E2 are positioned between the belt portion 11A2 and the line portion 11C3. The same goes for the belt portions 5A1, 5A2, the line portions 5C1 to 5C4, and the dummy portions 5E1, 5E2. The belt portions 5A1, 5A2 are examples of the first and second belt portions. The line portions 5C1 to 5C4 are examples of the first to fourth interconnects, respectively. The dummy portions 5E1, 5E2 are examples of the one or more fifth interconnects and the one or more sixth interconnects, respectively.
The dummy portions 11F1 are positioned between the belt portion 11B1 and the line portion 11D1, and the dummy portions 11F2 are positioned between the belt portion 11B2 and the line portion 11D3. The same goes for the belt portions 5B1, 5B2, the line portions 5D1 to 5D4, and the dummy portions 5F1, 5F2. The belt portions 5B1, 5B2 are examples of the first and second belt portions. The line portions 5D1 to 5D4 are examples of the first to fourth interconnects, respectively. The dummy portions 5F1, 5F2 are examples of the one or more fifth interconnects and the one or more sixth interconnects, respectively.
The belt portions 11A1, 11A2, 11B1, 11B2 in the present embodiment, similarly to the belt portions 11A, 11B in the first embodiment, are formed due to the reverse loading effect when the pattern of the first sidewall film 16 is transferred to the hard mask layer 13.
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Next, the belt portions 11A1, 11A2, 11B1, 11B2 are processed by lithography and etching (
As a result, the belt portion 11A1 is processed into a belt portion 11A3 connected with the line portion 11C1 and a belt portion 11A4 connected with the line portion 11C2. Further, the belt portion 11A2 is processed into a belt portion 11A5 connected with the line portion 11C4 and a belt portion 11A6 connected with the line portion 11C3. The belt portions 11A3, 11A4 are arranged so as to be close to and apart from each other in the Y direction, and the belt portions 11A5, 11A6 are arranged so as to be close to and apart from each other in the Y direction. Each of the dummy portions 11E1 is positioned between the line portion 11C1 and the belt portion 11A3 and/or 11A4, and each of the dummy portions 11E2 is positioned between the line portion 11C3 and the belt portion 11A5 and/or 11A6. The above etching is performed using a resist film that includes the trench TA in
Similarly to the belt portions 11A1, 11A2, the belt portions 5A1, 5A2 are processed into belt portions 5A3, 5A4, 5A5, 5A6 connected with the line portions 5C1, 5C2, 5C4, 5C3 respectively. The belt portions 5A3, 5A4, 5A5, 5A6 function as pad portions HU1, HU2, HU7, HU8 for the word lines WL1, WL2, WL7, WL8, respectively.
The same goes for the belt portions 11B1, 11B2 and the belt portions 5B1, 5B2. The belt portions 5B1, 5B2 are processed into belt portions 5B3, 5B4, 5B5, 5B6 connected with the line portions 5D1, 5D2, 5D4, 5D3 respectively. The belt portions 5B3, 5B4, 5B5, 5B6 function as pad portions HU3, HU4, HU5, HU6 for the word lines WL3, WL4, WL5, WL6, respectively.
Thereafter, in the present embodiment, an inter layer dielectric is formed on the whole surface of the substrate 1, contact holes that penetrate the inter layer dielectric and reach the pad portions HU1 to HU4 are formed, and contact plugs 21 are formed on the pad portions HU1 to HU4 in the contact holes. Furthermore, various interconnect layers, plug layers, inter layer dielectrics and the like are formed on the substrate 1. In this way, the semiconductor device of the present embodiment is manufactured.
According to the present embodiment, similarly to the first embodiment, it is possible to form the pad portions HU1 to HU8 simply and accurately.
The semiconductor device of the first embodiment includes the pad portions HU1 to HU4 for the word lines WL1 to WL4, within the region shown in
As shown in
Similarly, the pattern of each layer in the third embodiment has a shape that is bilaterally symmetric, at least before the step of
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First, the gate insulator 2, the floating gate material 3, the inter gate insulator 4, the control gate material 5, the first mask layer 11, the second mask layer 12, the hard mask layer 13, the core material 14, and the resist film 15 are formed in order, on the substrate 1 (
Next, the resist film 15 is processed by lithography (
The belt portions 15A, 15B extend in the X direction, and surround one or more opening portions PA and one or more opening portions PB, respectively. The line portions 15C, 15D extend in the Y direction, and are connected with the belt portions 15A, 15B, respectively. The opening portions PA, PB are positioned near ends of the line portions 15C, 15D, respectively. The dummy portions 15E are formed between the belt portion 15A and the belt portion 15B.
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Next, by the etching using the resist film 15 as a mask, the core material 14 is processed (
The belt portions 14A, 14B extend in the X direction, and surround one or more opening portions QA and one or more opening portions QB, respectively. The line portions 14C, 14D extend in the Y direction, and are connected with the belt portions 14A, 14B, respectively. The opening portions QA, QB are positioned near ends of the line portions 14C, 14D, respectively. The dummy portions 14E are formed between the belt portion 14A and the belt portion 14B. The dummy portions 14E have a point shape.
The belt portions 14A, 14B are examples of the first and second belt portions, respectively. The line portion 14C is an example of the first or second line portion. The line portion 14D is an example of the third or fourth line portion. The opening portion QA is an example of the first or second opening portion. The opening portion QB is an example of the third or fourth opening portion. The dummy portion 14E is an example of the first or second portion.
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Next, a first sidewall film 16 is formed on the side faces of the core material 14, and the core material 14 is removed by etching or ashing (
The first sidewall film 16 includes line portions 16C1, 16C2 formed on the side faces of the belt portion 14A and the line portion 14C, and line portions 16D1, 16D2 formed on the side faces of the belt portion 14B and the line portion 14D.
The first sidewall film 16 further includes dummy portions 16E formed on the side faces of the dummy portions 14E, dummy portions 16F formed on the side faces of the opening portions QA, and dummy portions 16G formed on the side faces of the opening portions QB. The dummy portions 16E, 16F, 16G have a ring shape.
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Next, a second sidewall film 17 is formed on the side faces of the first sidewall film 16, and the first sidewall film 16 is removed by etching or ashing (
The second sidewall film 17 includes line portions 17C1, 17C2 formed on the side faces of the line portion 16C1, line portions 17C3, 17C4 formed on the side faces of the line portion 16C2, line portions 17D1, 17D2 formed on the side faces of the line portion 16D1, and line portions 17D3, 17D4 formed on the side faces of the line portion 16D2.
The second sidewall film 17 further includes dummy portions 17E1, 17E2 formed on the side faces of the dummy portions 16E, dummy portions 17F1, 17F2 formed on the side faces of the dummy portions 16F, and dummy portions 17G1, 17G2 formed on the side faces of the dummy portions 16G. The dummy portions 17E1, 17E2, 17F1, 17F2, 17G1, 17G2 have ring shapes.
[
Next, by the etching using the second sidewall film 17 as a mask, the hard mask layer 13 is processed (
The belt portions 13A, 13B, 13H extend in the X direction. The line portions 13C1 to 13C4, 13D1 to 13D4 extend mainly in the Y direction. The line portions 13C2, 13C3 are connected with the belt portion 13A, and the dummy portions 13F1, 13F2 are positioned between the line portion 13C2 and the line portions 13C3.
The line portions 13C4, 13D1 are connected with the belt portion 13H, and the dummy portions 13E1, 13E2 are positioned between the line portion 13C4 and the line portion 13D1. The line portions 13D2, 13D3 are connected with the belt portion 13B, and the dummy portions 13G1, 13G2 are positioned between the line portion 13D2 and the line portion 13D3.
The belt portions 13A, 13B, 13H in the present embodiment are formed by the reverse loading effect. Further, at corner portions of the belt portions 13A, 13B, 13H in the present embodiment, opening portions RA, RB, RH are formed respectively, by the reverse loading effect.
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Next, the second mask layer 12, the first mask layer 11, the control gate material 5, the inter gate insulator 4, the floating gate material 3, and the gate insulator 2 are processed by the etching using the hard mask layer 13 as a mask (
The same goes for the control gate material 5, the inter gate insulator 4, the floating gate material 3 and the gate insulator 2. For example, the control gate material 5 is processed into a line pattern including belt portions 5A, 5B, 5H, line portions 5C1 to 5C4, 5D1 to 5D4, and dummy portions 5E1, 5E2, 5F1, 5F2, 5G1, 5G2.
The belt portions 5A, 5B, 5H, the line portions 5C1 to 5C4, 5D1 to 5D4, and the dummy portions 5E1, 5E2, 5F1, 5F2, 5G1, 5G2, for which the illustration of the reference characters and the shapes is omitted for the convenience of the figure drawing, are positioned under the belt portions 11A, 11B, 11H, the line portions 11C1 to 11C4, 11D1 to 11D4, and the dummy portions 11E1, 11E2, 11F1, 11F2, 11G1, 11G2, respectively. The line portions 5C2, 5C3, 5C4, 5D1, 5D2, 5D3 function as word lines WL1 to WL6, respectively.
The belt portions 11A, 11B, 11H extend in the X direction. The line portions 11C1 to 11C4, 11D1 to 11D4 extend mainly in the Y direction, and are arranged so as to be close to and apart from each other. The line portions 11C2, 11C3 are connected with the belt portion 11A, and the dummy portions 11F1, 11F2 are positioned between the line portion 11C2 and the line portion 11C3. The line portions 11C4, 11D1 are connected with the belt portion 11H, and the dummy portions 11E1, 11E2 are positioned between the line portion 11C4 and the line portion 11D1. The line portions 11D2, 11D3 are connected with the belt portion 11B, and the dummy portions 11G1, 11G2 are positioned between the line portion 11D2 and the line portion 11D3. The dummy portions 11E1, 11E2, 11F1, 11F2, 11G1, 11G2 have ring shapes. The dummy portions 11E2, 11F2, 11G2 are positioned within the dummy portions 11E1, 11F1, 11G1, respectively. At corner portions of the belt portions 13A, 13B, 13H in the present embodiment, opening portions SA, SB, SH are formed respectively.
The same goes for the belt portions 5A, 5B, 5H, the line portions 5C1 to 5C4, 5D1 to 5D4, and the dummy portions 5E1, 5E2, 5F1, 5F2, 5G1, 5G2. Each of the belt portions 5A, 5B, 5H is an example of the first belt portion. Each of the line portions 5C2 to 5C4, 5D1 to 5D3 is an example of one of the first to fourth interconnects. Each of the dummy portions 5E1, 5E2, 5F1, 5F2, 5G1, 5G2 is an example of the one or more fifth interconnects or the one or more sixth interconnects.
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Next, the belt portions 11A, 11B, 11H are processed by lithography or etching (
As a result, the belt portion 11A is processed into a belt portion 11A1 connected with the line portion 11C2 and a belt portion 11A2 connected with the line portion 11C3. Further, the belt portion 11H is processed into a belt portion 11H1 connected with the line portion 11C4 and a belt portion 11H2 connected with the line portion 11D1. Further, the belt portion 11B is processed into a belt portion 11B1 connected with the line portion 11D2 and a belt portion 11B2 connected with the line portion 11D3. The belt portions 11A, 11B, 11H in the present embodiment, similarly to the first embodiment, are disconnected from line portions that are positioned in the +X direction relative to the belt portions 11A, 11B, 11H.
Similarly to the belt portions 11A, 11B, 11H, the belt portions 5A, 5B, 5H are processed into belt portions 5A1, 5A2, 5H1, 5H2, 5B1, 5B2 connected with the line portions 5C2, 5C3, 5C4, 5D1, 5D2, 5D3 respectively. The belt portions 5A1, 5A2, 5H1, 5H2, 5B1, 5B2 function as pad portions HU1 to HU6 for the word lines WL1 to WL6, respectively.
Thereafter, in the present embodiment, an inter layer dielectric is formed on the whole surface of the substrate 1, contact holes that penetrate the inter layer dielectric and reach the pad portions HU1 to HU6 are formed, and contact plugs 21 are formed on the pad portions HU1 to HU6 in the contact holes. Furthermore, various interconnect layers, plug layers, inter layer dielectrics and the like are formed on the substrate 1. In this way, the semiconductor device of the present embodiment is manufactured.
According to the present embodiment, similarly to the first embodiment and the second embodiment, it is possible to form the pad portions HU1 to HU6 simply and accurately.
The pattern of each layer in the first to third embodiments may have a shape that is bilaterally asymmetric (that is asymmetric with respect to the Y axis).
Further, the first and second sidewall films 16, 17 in the third embodiment may be applied to the method of manufacturing the semiconductor device of the second embodiment.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel devices and methods described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the devices and methods described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
This application is based upon and claims the benefit of priority from the prior U.S. Provisional Patent Application No. 62/094,644 filed on Dec. 19, 2014, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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62094644 | Dec 2014 | US |