CN216488057U - Dynamic random access memory structure - Google Patents

Abstract

The application discloses a dynamic random access memory structure. The dynamic random access memory structure comprises: a plurality of bit lines which are parallel to each other in the horizontal direction and are arranged at intervals, and a plurality of word lines which are parallel to each other in the vertical direction and are arranged at intervals, wherein the distance from the upper boundary of any bit line to the upper boundary of another adjacent bit line is defined as BLP, and the distance from the left boundary of any word line to the left boundary of another adjacent word line is defined as WLP; a unit sub-pattern; a plurality of diagonal stepped patterns including a plurality of rectangular patterns of the same shape, the rectangular patterns being connected to each other in an overlapping manner and arranged along a first direction, a width of each rectangular pattern in a horizontal direction being defined as X, and a width of each rectangular pattern in a vertical direction not overlapping with an adjacent rectangular pattern being defined as Y; the unit sub-patterns include N diagonally stepped patterns. The dynamic random access memory structure can improve the uniformity of the overall pattern distribution.

Description

Dynamic random access memory structure

Technical Field

The present invention relates to the field of semiconductors, and more particularly, to a dynamic random access memory structure that facilitates improving the uniformity of the overall pattern layout.

Background

In recent years, electronic products are designed to have multifunction and fast processing capability. In order to increase processing power, for example, in computer systems or multi-function electronic products, large Dynamic Random Access Memories (DRAMs) are required. In order to increase the memory capacity, the size of the memory cell of the memory needs to be reduced, but the reduction of the size of the memory cell causes other problems, such that the operation of the memory cell is unstable or the memory cell is damaged.

Semiconductor devices are generally formed by forming a desired device structure on the basis of an active layer unit defined on a substrate. Therefore, the active layer unit on the substrate is the basis of the components, and the size, shape and position of the components are determined. The active layer unit is also referred to as a device unit hereinafter.

Taking the memory cell of the memory as an example, a plurality of component units are arrayed in a predetermined component area in a regular arrangement. A component unit will eventually form a memory cell. In addition, there are peripheral circuits around the memory cells to control the memory cells in order to operate the memory cells. These peripheral circuits are also formed on the basis of the peripheral active region.

Therefore, under the demand of reducing the size of the semiconductor device, how to design the device structure to maintain the normal operation of the device is also one of the issues to be considered.

SUMMERY OF THE UTILITY MODEL

The present disclosure is directed to a dynamic random access memory structure, which is helpful for improving the uniformity of the whole pattern.

According to an aspect of the present application, there is provided a dynamic random access memory structure comprising: a plurality of bit lines arranged parallel to each other in a horizontal direction at intervals, and a plurality of word lines arranged parallel to each other in a vertical direction at intervals, wherein a distance from an upper boundary edge of any one of the bit lines to an upper boundary edge of another adjacent bit line is defined as BLP, a distance from a left boundary edge of any one of the word lines to a left boundary edge of another adjacent word line is defined as WLP, and the horizontal direction is perpendicular to the vertical direction; a unit sub-pattern having a width of 4 xWLP and a length of 4 xBLP; a plurality of diagonal stepped patterns, wherein each of the diagonal stepped patterns includes a plurality of rectangular patterns having the same shape, the rectangular patterns are connected to each other in an overlapping manner and are arranged along a first direction, a width of each of the rectangular patterns in the horizontal direction is defined as X, a width of each of the rectangular patterns in the vertical direction, which does not overlap with an adjacent rectangular pattern, is defined as Y, and the following conditions are satisfied: BLP/3WLP ═ Y/X; wherein the unit sub-pattern comprises N oblique stepped patterns, and satisfies the following conditions: (4BLP + cxy)/N ═ integer, where C is 0 or a smallest positive integer greater than or equal to 1, N is an integer, and the first direction is different from the horizontal direction or the vertical direction.

Optionally, the first direction is parallel to a direction formed by connecting center points of the rectangular patterns, an included angle between the first direction and the horizontal direction is defined as a, and a condition is satisfied: a ═ tan^-1(BLP/3WLP)＝tan^-1(Y/X)。

Optionally, along a second direction, a shortest distance between two adjacent oblique stepped patterns is defined as P, wherein the second direction is perpendicular to the first direction.

Optionally, a distance from an upper boundary of any one of the diagonally stepped patterns to an upper boundary of another adjacent diagonally stepped pattern along the vertical direction is 2 PcosA.

Alternatively, N is equal to the integer portion of 4BLP/2 PcosA.

Optionally, in the unit sub-pattern, the plurality of oblique stepped patterns include a first rectangular pattern, a second rectangular pattern, and a third rectangular pattern, where the first rectangular pattern, the second rectangular pattern, and the third rectangular pattern are respectively located in three different and mutually adjacent oblique stepped patterns, and the first rectangular pattern, the second rectangular pattern, and the third rectangular pattern are aligned along a third direction, and the third direction has an included angle not equal to 90 degrees with the horizontal direction or the vertical direction.

Optionally, an included angle between the third direction and the vertical direction is defined as B, and satisfies a condition: b ═ tan^-1(C×X/4BLP+C×Y)。

Optionally, in the unit sub-patterns, in the vertical direction, a distance from an upper boundary of any one of the oblique stepped patterns to an upper boundary of another adjacent oblique stepped pattern is equal.

According to another aspect of the embodiments of the present application, there is also provided a dynamic random access memory structure, including: the pattern structure comprises a plurality of inclined stepped patterns which are arranged in parallel, wherein the inclined stepped patterns are formed by overlapping and arranging a plurality of rectangular patterns with the same size, each inclined stepped pattern comprises a plurality of rectangular patterns with the same size, the rectangular patterns are connected with each other and arranged along a first direction, one width of each rectangular pattern with the same size in a horizontal direction is defined as X, a part of each rectangular pattern which does not overlap with the adjacent rectangular pattern in a vertical direction is defined as Y, Y is not equal to 0, the horizontal direction is perpendicular to the vertical direction, and the first direction is different from the horizontal direction and the vertical direction.

Alternatively, two adjacent ones of the obliquely stepped patterns are respectively defined as an obliquely stepped pattern Pi and an obliquely stepped pattern Pi +1, wherein a right boundary of any one of the rectangular patterns of the obliquely stepped pattern Pi and a right boundary of any one of the rectangular patterns of the obliquely stepped pattern Pi +1 are not aligned with each other in the vertical direction.

Alternatively, the number of the obliquely stepped patterns is four, and the obliquely stepped patterns are sequentially defined as an obliquely stepped pattern Pi, an obliquely stepped pattern Pi +1, an obliquely stepped pattern Pi +2, and an obliquely stepped pattern Pi +3 in an arrangement order, wherein a right boundary of any one of the rectangular patterns of the obliquely stepped pattern Pi and a right boundary of any one of the rectangular patterns of the obliquely stepped pattern Pi +2 or the obliquely stepped pattern Pi +3 are aligned with each other in the vertical direction.

Alternatively, four of the obliquely stepped patterns are defined in order of an oblique stepped pattern Pi, an obliquely stepped pattern Pi +1, an obliquely stepped pattern Pi +2, and an obliquely stepped pattern Pi +3 in the arrangement order, wherein boundaries of the obliquely stepped pattern Pi and boundaries of the obliquely stepped pattern Pi +2 or the obliquely stepped pattern Pi +3 are aligned with each other in the vertical direction.

Optionally, the first direction is parallel to a direction formed by connecting center points of each of the rectangular patterns.

The present application is characterized in that, in the unit sub-patterns, an appropriate active region pattern is designed according to a Bit Line Pitch (BLP) and a Word Line Pitch (WLP), wherein the active region pattern is a stepped pattern formed by connecting a plurality of rectangles in series, and the active region pattern is arranged along a first direction, wherein an angle between the first direction and a horizontal direction is a. In addition, the positions of the partial stepped active region patterns are adjusted according to the angle A, the shortest distance (P) between the adjacent stepped patterns, the length and width of the unit sub-pattern and other relevance, so that the distances among the active region patterns can be kept consistent when the active region patterns are repeatedly arranged, and the uniformity of the overall pattern distribution is improved.

Drawings

FIG. 1 is a schematic diagram of a unit sub-pattern, wherein the unit sub-pattern includes four bit lines arranged along a horizontal direction and four word lines arranged along a vertical direction;

FIG. 2 is a partially enlarged schematic view of a portion of the unit sub-pattern and the active region;

FIG. 3 is a schematic diagram illustrating an angle A between the extending direction of the active region and the horizontal direction;

FIG. 4 is a schematic diagram of a stepped active region pattern;

FIG. 5 is a schematic diagram of an enlarged stepped active region pattern;

FIG. 6 is a schematic diagram illustrating an ideal arrangement of a plurality of active region patterns;

FIG. 7 is a schematic view showing an arrangement of a plurality of active region patterns in an area of a unit sub-pattern;

FIG. 8 is a schematic diagram showing the arrangement of a plurality of stepped active region patterns before modification within the area of a unit sub-pattern; and

fig. 9 is a schematic view showing an arrangement of a plurality of stepped active region patterns corrected in the area of the unit sub-patterns.

Detailed Description

The following detailed description refers to the accompanying drawings that illustrate embodiments that can be practiced in accordance with the teachings of the present application. These embodiments are provided with sufficient detail to enable those skilled in the art to fully understand and practice the present application. Structural and electrical changes may be made and other embodiments may be implemented without departing from the scope of the present application.

Fig. 1 is a schematic diagram of a unit sub-pattern SP, wherein the unit sub-pattern SP includes a plurality of bit lines arranged in parallel with each other along a horizontal direction, and a plurality of word lines arranged in parallel with each other along a vertical direction, the bit lines have widths, the word lines have widths, a distance from an upper boundary of any one of the bit lines to an upper boundary of another adjacent bit line is defined as BLP (bit line pitch), i.e., a distance between boundaries of two adjacent bit lines on the same side of a center line in the horizontal direction is defined as BLP, a distance from a left boundary of any one of the word lines to a left boundary of another adjacent word line is defined as WLP (word line pitch), a word line pitch, i.e., a distance between boundaries of two adjacent word lines on the same side of a center line in the vertical direction is defined as WLP, e.g., four bit lines (bit lines, BL) (bit lines) and four Word Lines (WL) (word lines) arranged in a vertical direction. In this embodiment, a unit sub-pattern (SP) is a minimum unit of a memory, and the minimum unit can be repeatedly copied and spread, for example, repeatedly arranged to form an array-shaped rectangular memory array on a substrate. In order to calculate the area of each unit sub-pattern SP, in the present embodiment, one unit sub-pattern SP includes four Bit Lines (BL) arranged parallel to each other along the horizontal direction (X axis) and four Word Lines (WL) arranged along the vertical direction (Y axis), a distance from an upper boundary of any one bit line to an upper boundary of another adjacent bit line is defined as BLP, similarly, a distance from a lower boundary of any one bit line to a lower boundary of another adjacent bit line is also BLP, a distance from a left boundary of any one word line to a left boundary of another adjacent word line is defined as WLP, and similarly, a distance from a right boundary of any one word line to a right boundary of another adjacent word line is also WLP. The distance BLP or the distance WLP is affected by the exposure limit (CD) of the photolithography process. Taking this embodiment as an example, the distance WLP is, for example, 52 nanometers (nm), and the distance BLP is, for example, 62 nm. And the length and width of a unit sub-pattern SP are 4BLP and 4WLP, respectively (as shown by the dotted lines in fig. 1). It should be noted that the distance WLP of 52nm and the distance BLP of 62nm in this embodiment are only an example of the present application, and the present application is not limited thereto, and these values can be adjusted.

Fig. 2 is a partially enlarged schematic view of a portion of the unit sub-pattern SP and the active area AA, and fig. 3 is an angle a between the extending direction of the active area and the horizontal direction. In fig. 2, a plurality of active regions AA are arranged along a first direction D1, and in fig. 3, it can be seen that the extending direction of the active regions AA is designed to be parallel to the diagonal line of the dashed boxes, wherein each of the dashed boxes has a length BLP and a width 3 WLP. The active area pattern AAP is formed on a substrate, and then etching and cutting steps are performed to form the active area AA in the substrate, so that the extending direction of the active area pattern AAP is equal to that of the active area AA formed later. In this embodiment, in order to achieve the preferred repetitive distribution effect, the active region pattern AAP may be designed to span 3 distances WLP in the horizontal direction when it spans 1 distance BLP in the vertical direction. That is, as shown by the dotted lines of fig. 2 and 3, each of the active region patterns AAP is parallel to a diagonal direction of the dotted line. Wherein an angle between the extending direction of the active area pattern AAP (i.e., the first direction D1) and the horizontal direction may be defined as a, and the angle a is equal to tan^-1(BLP/3 XWLP). Taking this embodiment as an example, if BLP is 62 nm; if WLP is 52nm, angle a is equal to about 21.67 degrees, but the application is not limited thereto.

Fig. 4 is a schematic diagram of a stepped active region pattern, and fig. 5 is a schematic diagram of an enlarged stepped active region pattern AAP. Please note that the step-like active area pattern AAP drawn from fig. 4 and its adjustment steps may be related in a computer, and then the pattern is outputted to a mask, and then the pattern is transferred to the substrate by using the mask as a mask. As shown in fig. 4 and 5In the manufacturing process, the diagonally arranged active area patterns AAP are preferably formed by step-like patterns, wherein each step-like pattern includes a plurality of rectangular patterns R arranged in series along the first direction D1, that is, the first direction D1 is a direction formed by connecting the center points of each rectangular pattern R. In the present embodiment, the width X is defined as the width of each rectangular pattern R in the horizontal direction, and the level difference Y is defined as the length of each rectangular pattern R not overlapping with another adjacent rectangular pattern R in the vertical direction. Since the angle A between the first direction and the horizontal direction is tan^-1(BLP/3 XWLP), so the ratio of the width X to the step Y also needs to satisfy this condition, that is tan^-1(BLP/3×WLP)＝tan^-1(Y/X), or BLP/3 × WLP ═ Y/X for simplification. The width X and the step Y may be suitable values, but the width X and the step Y are also limited by the exposure limit (CD) of the photolithography process, and thus cannot be reduced without limitation. In this example, X is 39nm and Y is 15.5 nm.

In order to clearly show the numerical values of the distances (e.g., length, width, pitch) and the angles from fig. 6, some numerical values are directly shown on the figure. It should be understood that these numerical values are only one example of the present embodiment, and the present application may adjust these numerical values according to the actual requirements. Fig. 6 is a schematic diagram illustrating an ideal arrangement of a plurality of active area patterns AAP. In an ideal state, when a plurality of active region patterns AAP are arranged on a substrate, the active region patterns AAP should be equally spaced from each other. Setting the shortest distance from any active area pattern AAP to another adjacent active area pattern AAP along a second direction D2 as a distance P, wherein the second direction D2 is perpendicular to the first direction D1, the distance P is, for example, 38.4nm (the value is also influenced by the exposure extreme value CD), and the included angle between each active area pattern AAP and the horizontal direction is tan^-1(BLP/3 × WLP), for example, 21.67 degrees, so that a distance from an upper edge of any one of the active region patterns AAP to an upper edge of another adjacent active region pattern AAP along the vertical direction is 2P/cosA ═ 2 × 38.4/cos21.67 degrees ═ 82.6nm (this value is hereinafter abbreviated as "2P/cosA")An upper edge distance).

Fig. 7 is a schematic view showing an arrangement of a plurality of active region patterns AAP in the area of the unit sub-pattern SP, and fig. 8 is a schematic view showing an arrangement of a plurality of stepped active region patterns AAP before correction in the area of the unit sub-pattern SP. As shown in fig. 7, the length of the unit sub pattern SP is 4BLP, and N active area patterns AAP can be placed in the unit sub pattern by dividing the integer part N obtained by dividing the length 4 × WLP of the unit sub pattern SP by the calculated 2P/cosA (the upper edge distance of the adjacent active area pattern AAP). In the present embodiment, it is 248nm/82.6 nm-3.0024. The integer part N is 3, which means that a maximum of 3 active region patterns AAP can be placed in the unit sub-pattern SP area (N is 3).

However, in practice, as shown in fig. 8, if the length 248nm in the vertical direction is equally allocated to three active area patterns AAP, the upper edge distance between some active area patterns AAP is 82.6nm, and the upper edge distance between some active area patterns AAP is 82.7nm, although there is a difference of only 0.1nm, when the unit sub-patterns SP are repeatedly arranged on the substrate, the slight error of 0.1nm is continuously amplified.

Therefore, after the active region patterns AAP are distributed in the unit sub-patterns SP, an adjustment step is further performed to make the distance between each active region pattern AAP and the upper edge of the adjacent active region pattern AAP equal. As shown in fig. 8 and 9, one rectangular pattern R (indicated by oblique lines in fig. 8 and 9) of an active area pattern AAP is selected, and other adjacent rectangular patterns are also marked in the vertical direction, such as a first rectangular pattern Ri, a second rectangular pattern Ri +1, a third rectangular pattern Ri +2, and a fourth rectangular pattern Ri + 3. In this embodiment, since only up to three active area patterns AAP can be placed in the unit sub-pattern SP, the first rectangular pattern Ri, the second rectangular pattern Ri +1, and the third rectangular pattern Ri +2 should be located in the same unit sub-pattern SP, and the fourth rectangular pattern Ri +3 should be located in another adjacent unit sub-pattern SP, corresponding to N and repeated. In the adjusting step, the horizontal and vertical distances between the first rectangular pattern Ri and the second rectangular pattern Ri +1, between the third rectangular pattern Ri +2, and between the fourth rectangular pattern Ri +3 are adjusted by using the value of the step Y. In detail, the length 4BLP of the original unit sub-pattern SP is gradually added to the value of the C-th order difference Y until the value can be evenly divided by the number (3 in the present embodiment) of the active area patterns AAP in the unit sub-pattern SP, that is, the condition of (4BLP + C × Y)/N is satisfied, where C is 0 or the smallest positive integer greater than or equal to 1, and N is an integer.

For the example of this embodiment, 4BLP 248 nm; n is 3; y15.5 nm:

if C is 1, it is verified that (248+1 × 15.5)/3 is 87.83, and the division cannot be performed, so C is not equal to 1, and it is necessary to continue testing C2, 3, 4, and 5 … until the division can be performed, and find the minimum C value:

if C is 2, then (248+2 × 15.5)/3 is verified to be 93, divisible, so C equals 2.

After the rectangular pattern Ri +3 is added with the step difference Y twice, as shown in fig. 9, fig. 9 is a schematic arrangement diagram of the plurality of stepped active area patterns AAP after being corrected within the area of the unit sub-pattern SP. The distance between the corrected rectangular pattern Ri +3 and the rectangular pattern Ri in the vertical direction is defined as H, where H is 4BLP + C × Y, and this embodiment H is 248nm +2 × 15.5nm is 279 nm; the horizontal distance between the corrected rectangular pattern Ri +3 and the rectangular pattern Ri is defined as W, where W is C × X, and in this embodiment, W is 2 × 39 — 78 nm. Therefore, an oblique line L can be drawn between the modified rectangular pattern Ri +3 and the rectangular pattern Ri, wherein the oblique line L can extend along a third direction D3, wherein the third direction D3 is different from the horizontal direction X or the vertical direction Y, that is, an included angle between the third direction and the horizontal direction X or the vertical direction Y is not equal to 90 degrees, an included angle between the third direction D3 and the vertical direction is B, and the included angle B ═ tan is^-1(CxX/4 BLP + CxY). As shown in fig. 9, the modified first rectangular pattern Ri, second rectangular pattern Ri +1, third rectangular pattern Ri +2, etc. are arranged along an oblique line L, i.e., the vertices of the non-overlapping portions of the modified first rectangular pattern Ri, second rectangular pattern Ri +1, third rectangular pattern Ri +2, and fourth rectangular pattern Ri +3 are all on a straight line L. Also seen in fig. 9 is a modified multi-step active area mapThe distances between the upper edges of the AAPs are all the same (93 nm for the example of FIG. 9). Therefore, the method for adjusting the stepped active area pattern provided by the application is beneficial to enabling the pattern distribution to be more uniform and improving the process yield.

In addition, in this embodiment, since N is 3, each three of the plurality of stepped active area patterns AAP is a group, and the plurality of groups of stepped active area patterns AAP are repeatedly arranged. That is, the fourth rectangular pattern Ri is aligned with the fifth rectangular pattern Ri +3 in the vertical direction.

It should be noted that the values described in the above embodiments, including WLP, BLP, X, Y, N, C, etc., may be adjusted according to actual requirements, and if C is equal to 0 in some embodiments, it means that no adjustment step is required.

In summary, the present application provides a dram structure, which includes: a plurality of bit lines (bit lines BL) arranged parallel to each other in a horizontal direction, and a plurality of word lines (word lines WL) arranged parallel to each other in a vertical direction, where the upper boundary edge of any one bitline to the upper boundary edge of another adjacent bitline is defined as BLP, and a left boundary of any one word line to a left boundary of another adjacent word line is defined as WLP, a unit sub-pattern SP, the unit sub-pattern has a width of 4WLP, a length of 4BLP, a plurality of inclined step-like patterns (active area patterns AAP), each of the slant step-like patterns includes a plurality of rectangular patterns R connected to each other and arranged along a first direction D1, wherein a width of each rectangular pattern R in the horizontal direction is defined as X, and a portion of each rectangular pattern in the vertical direction which does not overlap with the adjacent rectangular pattern is defined as Y, and the following conditions are satisfied: BLP/3WLP is Y/X, where N of the oblique stepped patterns are located in the unit sub-pattern, and the condition is satisfied: (4BLP + cxy)/N ═ integer, where C is 0 or the smallest positive integer greater than or equal to 1, and where N is an integer.

Optionally, an included angle between the first direction D1 and the horizontal direction (X axis) is defined as a, and satisfies a condition: a is tan-1(BLP/3WLP) tan-1 (Y/X).

Optionally, a shortest distance between two adjacent diagonal stepped patterns along a second direction D2 is defined as P, wherein the second direction D2 is perpendicular to the first direction D1.

Optionally, a distance from an upper boundary of any one of the oblique stepped patterns to an upper boundary of another adjacent one of the oblique stepped patterns along the vertical direction is 2 PcosA.

Optionally, where N is equal to the integer portion of 4BLP/2 PcosA.

Optionally, the unit sub-patterns include a first rectangular pattern Ri, a second rectangular pattern Ri, and a third rectangular pattern Ri +2, wherein the first rectangular pattern Ri, the second rectangular pattern Ri +1, and the third rectangular pattern Ri +2 are respectively located in three different and mutually adjacent slant stepped patterns AAP, and the first rectangular pattern Ri, the second rectangular pattern Ri +1, and the third rectangular pattern Ri +2 are aligned along a third direction D3.

Optionally, an angle between the third direction D3 and the vertical direction (Y axis) is defined as B, and satisfies the following condition: b ═ tan^-1(C×X/4BLP+C×Y)。

Alternatively, wherein the first direction D1 is different from the horizontal direction (X-axis) or the vertical direction (Y-axis).

Alternatively, in the unit sub-pattern SP, distances from an upper boundary of any one of the inclined stepped patterns (active area patterns AAP) to an upper boundary of another adjacent inclined stepped pattern (active area pattern AAP) in the vertical direction (Y axis) are equal.

The application provides a method for forming a dynamic random access memory structure, comprising the following steps: forming a plurality of bit lines (bit lines BL) arranged in parallel with each other in a horizontal direction, and forming a plurality of word lines (word lines WL) arranged in parallel with each other in a vertical direction, wherein an upper boundary of any one of the bit lines to an upper boundary of another adjacent bit line is defined as BLP, and a left boundary of any one of the word lines to a left boundary of another adjacent word line is defined as WLP, defining a unit sub-pattern SP having a width of 4WLP and a length of 4BLP, forming a plurality of diagonal ladder patterns (active area patterns AAP), wherein each of the diagonal ladder patterns comprises a plurality of rectangular patterns R connected to each other and arranged in a first direction D1, wherein a width of each rectangular pattern R in the horizontal direction is defined as X, and a distance of each rectangular pattern R in the vertical direction not overlapping with the adjacent rectangular pattern is defined as Y, and satisfies the following conditions: BLP/3WLP is Y/X, where N of the oblique stepped patterns are located in the unit sub-pattern, and the condition is satisfied: (4BLP + cxy)/N ═ integer, where C is 0 or the smallest positive integer greater than or equal to 1, and N is an integer.

Optionally, an angle between the first direction D1 and the horizontal direction (X axis) is defined as a, and a condition is satisfied: a ═ tan^-1(BLP/3WLP)＝tan^-1(Y/X)。

Optionally, a shortest distance between two adjacent diagonal stepped patterns along a second direction D2 is defined as P, wherein the second direction D2 is perpendicular to the first direction D1.

Alternatively, a distance from an upper boundary of any one of the inclined stepped patterns (active area patterns AAP) to an upper boundary of another adjacent inclined stepped pattern (active area pattern AAP) along the vertical direction is 2 PcosA.

Optionally, where N is equal to the integer portion of 4BLP/2 PcosA.

Optionally, the step of forming the plurality of inclined stepped patterns (active area patterns AAP) includes: defining the positions of a plurality of initial oblique step patterns (active area patterns AAP) (as shown in fig. 8), and adjusting the positions of a portion of the initial oblique step patterns to form the plurality of oblique step patterns (as shown in fig. 9).

Optionally, in the unit sub-pattern, the plurality of initial slant step patterns include a first rectangular pattern Ri, a second rectangular pattern Ri +1, and a third rectangular pattern Ri +2, wherein the first rectangular pattern Ri, the second rectangular pattern Ri +1, and the third rectangular pattern Ri +2 are respectively located in three different and mutually adjacent initial slant step patterns (active area patterns AAP), and the first rectangular pattern Ri, the second rectangular pattern Ri +1, and the third rectangular pattern Ri +2 are aligned along the vertical direction.

Optionally, after adjusting the positions of some of the initial oblique stair step patterns to form the oblique stair step patterns, the first rectangular pattern Ri, the second rectangular pattern Ri +1 and the third rectangular pattern Ri +1 are aligned along a third direction D3 in the unit sub-pattern SP.

Optionally, an included angle between the third direction D3 and the vertical direction is defined as B, and satisfies the following condition: b ═ tan^-1(C×X/4BLP+C×Y)。

Optionally, wherein the first direction D1 is different from the horizontal direction or the vertical direction.

Optionally, in the unit sub-patterns SP, in the vertical direction, a distance from an upper boundary of any one of the inclined stepped patterns (active area patterns AAP) to an upper boundary of another adjacent inclined stepped pattern (active area pattern AAP) is equal.

The present application provides a dram structure, including a plurality of ramp-like patterns (active area patterns AAP) arranged in parallel with each other, wherein each ramp-like pattern is formed by repeatedly arranging a plurality of rectangular patterns R, wherein each ramp-like pattern includes a plurality of rectangular patterns R connected to each other and arranged along a first direction D1, wherein a width of each rectangular pattern R in a horizontal direction is defined as X, and a distance in the vertical direction at which each rectangular pattern does not overlap with an adjacent rectangular pattern is defined as Y.

Optionally, two adjacent oblique stepped patterns are respectively defined as Pi and Pi +1, wherein a right boundary of a rectangular pattern of the oblique stepped pattern Pi and a right boundary of a rectangular pattern of the oblique stepped pattern Pi +1 are not aligned with each other in a vertical direction.

Optionally, four of the inclined stepped patterns are sequentially defined as Pi, Pi +1, Pi +2 and Pi +3 according to the arrangement order, wherein a right boundary of a rectangular pattern of the inclined stepped pattern Pi and a right boundary of a rectangular pattern of the inclined stepped pattern Pi +2 or the inclined stepped pattern Pi +3 are not aligned with each other in a vertical direction.

The present application is characterized in that, in the unit sub-patterns, a suitable active region pattern is designed according to a Bit Line Pitch (BLP) and a Word Line Pitch (WLP), wherein the active region pattern is a stepped pattern formed by connecting a plurality of rectangular patterns in series, the active region pattern is arranged along a first direction, and an angle between the first direction and a horizontal direction is a. In addition, the positions of the partial stepped active region patterns are adjusted according to the angle A, the shortest distance (P) between the adjacent stepped patterns, the length and width of the unit sub-pattern and other relevance, so that the distances among the active region patterns can be kept consistent when the active region patterns are repeatedly arranged, and the uniformity of the overall pattern distribution is improved.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (8)

1. A dynamic random access memory structure, comprising:

a plurality of bit lines arranged parallel to each other in a horizontal direction at intervals, and a plurality of word lines arranged parallel to each other in a vertical direction at intervals, wherein a distance from an upper boundary edge of any one of the bit lines to an upper boundary edge of another adjacent bit line is defined as BLP, a distance from a left boundary edge of any one of the word lines to a left boundary edge of another adjacent word line is defined as WLP, and the horizontal direction is perpendicular to the vertical direction;

a unit sub-pattern, which is a minimum unit of one memory, having a width of 4 xWLP and a length of 4 xBLP;

a plurality of diagonal stepped active area patterns, wherein each of the diagonal stepped active area patterns includes a plurality of rectangular patterns having the same shape, the rectangular patterns are connected to each other in an overlapping manner and are arranged along a first direction, a width of each of the rectangular patterns in the horizontal direction is defined as X, a width of each of the rectangular patterns in the vertical direction, which does not overlap with an adjacent rectangular pattern, is defined as Y, and the following conditions are satisfied: BLP/3WLP = Y/X; wherein the unit sub-pattern comprises N oblique stepped patterns, and satisfies the following conditions: (4BLP + C × Y)/N = integer, where C is 0 or a smallest positive integer greater than or equal to 1, N is an integer, and the first direction is different from the horizontal direction or the vertical direction.

2. The dram structure of claim 1, wherein the first direction is parallel to a direction formed by connecting center points of each of the rectangular patterns, and an angle between the first direction and the horizontal direction is defined as a, and satisfies a condition: a = tan^-1(BLP/3WLP)=tan^-1(Y/X)。

3. The dram structure of claim 2, wherein a shortest distance between two adjacent slanted staircase patterns along a second direction is defined as P, wherein the second direction is perpendicular to the first direction.

4. The dynamic random access memory structure of claim 3, wherein along the vertical direction, the distance from the upper boundary of any one of the diagonal ladder-like patterns to the upper boundary of another adjacent diagonal ladder-like pattern is 2 PcosA.

5. The dynamic random access memory structure of claim 4, wherein N is equal to an integer portion of 4BLP/2 PcosA.

6. The dram structure of claim 1, wherein the plurality of slanted step patterns include a first rectangular pattern, a second rectangular pattern, and a third rectangular pattern within the unit sub-pattern, wherein the first rectangular pattern, the second rectangular pattern, and the third rectangular pattern are respectively located within three different and adjacent slanted step patterns, and the first rectangular pattern, the second rectangular pattern, and the third rectangular pattern are aligned along a third direction having an included angle not equal to 90 degrees with the horizontal direction or the vertical direction.

7. The dram structure of claim 6 wherein an angle between the third direction and the vertical direction is defined as B, and satisfies the condition: b = tan^-1 (C×X/4BLP+C×Y)。

8. The dram structure of claim 1, wherein an upper boundary of any one of the diagonal ladder-like patterns is equidistant from an upper boundary of another adjacent diagonal ladder-like pattern in the vertical direction within the unit sub-pattern.

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