SEMICONDUCTOR STRUCTURE, ITS READ/WRITE CONTROLLING AND METHOD OF MAKING THE SAME

The disclosed semiconductor structure includes: a substrate and a data line on the substrate, the data line extends along a first direction; the first transistor and the second transistor located on the first transistor's side away from the data line; each of the first transistor and the second transistor includes: a semiconductor column, the semiconductor column is located on a part of the top surface of the data line and extends along the third direction; an isolation structure inside the semiconductor column; along the second direction, the thickness of the isolation structure in different regions in the third direction is different, and the isolation structure runs through the semiconductor columns, and two of the first, the second and the third directions intersect each other. This improves the sensitivity of the second transistor to the change in current in the first transistor while reducing the leakage current in the first transistor.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of priority of Chinese patent application with the application number 202211185511.6, entitled “SEMICONDUCTOR STRUCTURE, ITS READ/WRITE CONTROLLING AND METHOD OF MAKING THE SAME”, filed on Sep. 27, 2022, the contents of which are incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of semiconductor technology, in particular to a semiconductor structure and its read/write control method and manufacturing method.

BACKGROUND

During developing higher integration density of dynamic memory devices, at the time of researching on the transistor structures in the dynamic memory array and reducing the size of a single functional device structure in the dynamic memory array, it is also needed to improve the electrical performance of those small-size functional devices.

When applying a vertical GAA (Gate-All-Around) transistor structure as a dynamic memory selection transistor (access transistor), the occupied area can reach 4F2 (F: minimum pattern size available under given process conditions). Although in principle a higher density efficiency can be achieved, but it is not easy to manufacture the capacitance structures that work with the GAA transistor to complete the data storage and reading work, and it is not easy to form a capacitance structure with a large aspect ratio and a high dimensional accuracy, so it is difficult to further improve the electrical performance of the dynamic memory devices.

SUMMARY

Embodiments of the present disclosure provide a semiconductor structure and its reading and writing control method and manufacturing method, the technique reduces the leakage current in the first transistor and improves the sensitivity of the second transistor to the current change in the first transistor, so to enhance the electrical performance.

Some embodiments of the present disclosure provide a semiconductor structure which includes: a substrate and data line located on the substrate, the data lines extend along a first direction; a first transistor on the top of the data line and the second transistor on the side away from the data line of the first transistor; wherein, both the first transistor and the second transistor include: a semiconductor column, and the semiconductor column is located at part of the top surface of the data line extends along the third direction; the semiconductor column has an isolation structure inside, along the second direction, the thickness of the isolation structure in different regions is different in the third direction, and the isolation structure runs through the semiconductor column, and the first direction, the second direction and the third direction intersect each other.

In some embodiments, the semiconductor column has opposite first and second sides in the second direction, a direction along the first side pointing to the inside of the semiconductor column, and a direction along the second side points in a direction inside the semiconductor column, and the thickness of the isolation structure gradually decreases in the third direction.

In some embodiments, the semiconductor column on the side of the isolation structure close to the data line is a first semiconductor column, and the first transistor includes the first semiconductor column; the first transistor also includes: a gate structure located on a part of the sidewall extending along the second direction and surrounding the first semiconductor column.

In some embodiments, the semiconductor column located on the side of the isolation structure away from the data line is a second semiconductor column, and the second transistor includes the second semiconductor column; the second transistor, it also includes: a first conductive layer located on part of the sidewall of the second semiconductor column extending along the third direction; a second conductive layer located on the top surface of the second semiconductor column away from the data line; a dielectric layer between the first conductive layer and the second semiconductor column, and between the second conductive layer and the second semiconductor column.

In some embodiments, if the second transistor is in an on state, the second semiconductor column directly opposite to the first conductive layer and directly opposite to the second conductive layer constitutes the first For the channel region of the second transistor, the first conductive layer, the second conductive layer and the channel region constitute a transmission path for the conduction current of the second transistor.

In some embodiments, the second transistor comprises a single electron transistor.

In some embodiments, the dielectric layer includes a first dielectric layer and a second dielectric layer, the first dielectric layer is located between the first conductive layer and the second semiconductor column, and the first dielectric layer is located between the second conductive layer and the second semiconductor column; along the third direction, the average thickness of the isolation structure is the first thickness, and the thickness of the second dielectric layer is A second thickness, along the second direction, the thickness of the first dielectric layer is a third thickness, the first thickness is greater than the second thickness, and the first thickness is greater than the third thickness.

In some embodiments, the second thickness is equal to the third thickness.

In some embodiments, the dielectric layer surrounds the sidewall of the second semiconductor column extending along the third direction; the first conductive layer extends along the second direction, and the first conductive layer corresponds to the plurality of second semiconductor columns arranged at intervals along the second direction.

In some embodiments, the second conductive layer extends along the first direction, and the second conductive layer corresponds to the plurality of semiconductor columns arranged at intervals along the first direction.

In some embodiments, along the third direction, the first semiconductor column includes a first region, a second region and a third region arranged in sequence; wherein, the first region and the data line contact connection, the gate structure surrounds the sidewall extending along the third direction of the second region, and the third region is contact-connected to the isolation structure; the projection of the positive side of the third region on the substrate is a first orthographic projection, the orthographic projection of the second semiconductor column on the substrate is a second orthographic projection, and the second orthographic projection is located in the first orthographic projection.

In some embodiments, the gate structure includes: a gate dielectric layer extending along the second direction and surrounding a part of the sidewall of the first semiconductor column; a gate surrounding the gate dielectric layer away from One side of the second semiconductor column; along the second direction, the thickness of the gate dielectric layer is the fourth thickness, and the dielectric layer between the first conductive layer and the second semiconductor column, the thickness of the layer is a third thickness, the fourth thickness is greater than the third thickness.

According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure also provide a method for controlling reading and writing of a semiconductor structure, including: providing the semiconductor structure as described in any one of the above, where the isolation structure is located close to the semiconductor column on the side of the data line is a first semiconductor column, the semiconductor column on the side of the isolation structure away from the data line is a second semiconductor column, and the first semiconductor column is separated from the isolation structure. A part of the structural contact area is a storage node; the second transistor includes: a first conductive layer located on part of the sidewall of the second semiconductor column extending along the third direction; a second conductive layer located on the second semiconductor column is far away from the top surface of the data line; the first transistor is turned on to adjust the voltage at the storage node to realize the write operation to the storage node; the voltage at the storage node is determined by the conductivity of the second semiconductor column, applying a first voltage to one of the first conductive layer and the second conductive layer, detecting a second voltage at another of the first conductive layer and the second conductive layer which the first voltage is not applied to, and the conductivity of the second semiconductor column is determined by a difference between the second voltage and the first voltage, wherein the conductivity of the second semiconductor column determines the voltage at the storage node, so as to realize the read operation on the storage node.

In some embodiments, along the third direction, the first transistor includes a first region, a second region and a third region arranged in sequence, and surrounding the second region along the third direction A gate structure with extended sidewalls, the first region is contact-connected to the data line, the third region is contact-connected to the isolation structure, and the third region is the storage node; the write operation of the storage node includes: applying a third voltage to the data line, and applying a fourth voltage to the gate structure, so as to turn on the transmission path between the first region and the third region, causing the voltage at the third region to be affected by the voltage on the data line, so as to implement a write operation to the third region.

According to some embodiments of the present disclosure, another aspect of the present disclosure provides a method for manufacturing a semiconductor structure, including: providing an initial substrate; forming a data line and a first transistor in the initial substrate, the data A line extends along a first direction, one end of the first transistor is contacted and connected to the data line, and the initial substrate is left as a substrate; a second transistor is formed on a side of the first transistor away from the data line; wherein, the first transistor and the second transistor both include: a semiconductor column, the semiconductor column is located on a part of the top surface of the data line and extends along the third direction; the semiconductor column has an isolation structure inside, along the first In the two directions, the thickness of the isolation structure in different regions in the third direction is different, and the isolation structure penetrates the semiconductor column, and two of the first direction, the second direction and the third direction are intersecting.

In some embodiments, the forming the data line and the first transistor in the initial substrate includes: patterning the initial substrate to form the data lines which are arranged at intervals, and initial semiconductor columns are formed on a part of the top surface of the data lines, and the initial substrate is left as a substrate; a gate structure is formed, and the gate structure extends along the second direction And surrounding part of the sidewall of the initial semiconductor column, part of the initial semiconductor column and the gate structure constitute the first transistor.

In some embodiments, along the third direction, the initial semiconductor column includes a first region, a second region, a third region, a fourth region and a fifth region arranged in sequence, and the gate structure Surrounding the sidewall extending along the third direction in the second region; the step of forming the isolation structure includes: extending in the third direction in the first region, the third region and the fifth region forming a protective layer on the extended sidewalls, exposing only the sidewalls of the fourth region extending along the third direction; performing oxidation treatment on the exposed sidewalls of the fourth region to convert the fourth region For the isolation structure, the original semiconductor column remains as the semiconductor column; wherein, the semiconductor column located on the side of the isolation structure close to the data line is a first semiconductor column, and the semiconductor column located on the isolation structure away from the semiconductor column on one side of the data line is a second semiconductor column, the first region, the second region and the third region constitute the first semiconductor column, and the fifth region serves as the second semiconductor column.

In some embodiments, the oxidizing the exposed sidewall of the fourth region includes: performing an in-situ water vapor generation process on the exposed sidewall of the fourth region.

In some embodiments, after forming the isolation structure, the step of forming the second transistor includes: forming a first conductive layer, a dielectric layer and a second conductive layer, the first conductive layer is located on the part of the sidewall of the second semiconductor column extending along the third direction, the second conductive layer is located on the top surface of the second semiconductor column away from the data line, the dielectric layer is located on the first conductive layer between the second semiconductor column and between the second conductive layer and the second semiconductor column.

In some embodiments, the step of forming the dielectric layer includes: removing part of the protective layer of the sidewall of the second semiconductor column extending along the third direction, to expose the second semiconductor part of the sidewall of the pillar extending along the third direction, and exposing a side of the second semiconductor column away from the isolation structure; forming the dielectric layer on the exposed surface of the second semiconductor column.

In some embodiments, forming the dielectric layer on the exposed surface of the second semiconductor column includes: performing oxidation treatment on the exposed second semiconductor column, so that a dielectric layer is formed on the remaining surfaces of the second semiconductor column.

In some embodiments, other surfaces of the second semiconductor column are exposed except the side contacting with the isolation structure, and the protection layer is located on other surfaces of the second semiconductor column; after the second semiconductor column, before removing the protection layer, the method further includes: forming a first isolation layer extending along the second direction, the first isolation layer being located at phases arranged at intervals along the first direction. Adjacent to the second semiconductor columns.

In some embodiments, the dielectric layer includes a first dielectric layer and a second dielectric layer, the first dielectric layer is located between the first conductive layer and the second semiconductor column, and the second dielectric layers are located between the second conductive layer and the second semiconductor column; the steps of forming the first dielectric layer, the first conductive layer and the second dielectric layer include: An initial first dielectric layer is formed on the surface of the second semiconductor column, and the first isolation layer and the initial first dielectric layer enclose a first interval; an initial first conductive layer is formed in the first interval, and the initial first dielectric layer is formed in the first interval. A conductive layer fills the first gap and is located on the side of the initial first dielectric layer away from the second semiconductor column; etching back the initial first conductive layer, leaving the initial first conductive layer layer as the first conductive layer, and in the etch-back step, the initial first dielectric layer located on the top surface of the second semiconductor column away from the isolation structure is removed, and the initial first dielectric layer remains. The dielectric layer is used as the first dielectric layer, and part of the sidewall of the first dielectric layer extending along the third direction is exposed; a second isolation layer is formed, and the second isolation layer and the first conductive layer share filling the first gap; forming the second dielectric layer on the top surface of the second semiconductor column away from the first dielectric layer.

According to some embodiments of the present disclosure, another embodiment of the present disclosure further provides a transistor structure.

The technical scheme that the embodiment of the present disclosure provides has the following advantages:

The first transistor includes a part of the semiconductor column extending along the third direction, then the first transistor can be used as a GAA transistor, which is beneficial to reduce the leakage current in the first transistor. Moreover, the second transistor includes another part of semiconductor columns extending along the third direction. It can be understood that the semiconductor columns in the first transistor and the semiconductor columns in the second transistor can be integrally formed, and there is an isolation structure between the first transistor and the second transistor, so that it is beneficial to reduce the defect state density between the semiconductor column and the isolation structure in the first transistor, and reduce the defect state density between the semiconductor column and the isolation structure in the second transistor, thereby effectively it is beneficial to improve the electrical performance of the semiconductor structure as a whole. In addition, the first transistor can be used as a dynamic memory selection transistor, and the second transistor can be used as a structure for storing data, that is, as a capacitive structure. In this way, the storage or reading operation of data is realized through the first transistor and the second transistor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present disclosure provide a semiconductor structure and its reading and writing control method and manufacturing method. In the semiconductor structure, the first transistor includes a part of the semiconductor column extending along the third direction, then the first transistor can be used as a GAA transistor, so it is beneficial to increase the integration density of the first transistor in the semiconductor structure and reduce the leakage current in the first transistor. Moreover, the second transistor includes another part of semiconductor columns extending along the third direction. It can be understood that the semiconductor columns in the first transistor and the semiconductor columns in the second transistor can be integrally formed, and there is an isolation structure between the first transistor and the second transistor, so that it is beneficial to reduce the defect state density between the semiconductor column and the isolation structure in the first transistor, and reduce the defect state density between the semiconductor column and the isolation structure in the second transistor, thereby effectively it is beneficial to improve the electrical performance of the semiconductor structure as a whole. In addition, the first transistor can be used as a dynamic memory selection transistor, and the second transistor can be used as a structure for storing data, that is, the role of a capacitor structure. In this way, the storage or reading operation of data is realized through the first transistor and the second transistor. Moreover, compared with the current capacitive structure, the second transistor has a smaller size and higher sensitivity to current changes in the first transistor.

Various embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that, in each embodiment of the present disclosure, many technical details are provided for readers to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be realized.

An embodiment of the present disclosure provides a semiconductor structure, and the semiconductor structure provided by an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.1is a schematic diagram of a three-dimensional structure corresponding to a semiconductor structure provided by an embodiment of the present disclosure;FIG.2is a schematic cross-sectional view of the structure shown inFIG.1along the first cross-sectional direction AA1;FIG.3is a schematic cross-sectional view of the structure shown inFIG.1along the second cross-section A schematic cross-sectional view of direction BB1;FIG.4is a schematic top view of a gate structure and a first conductive layer in a semiconductor structure provided by an embodiment of the present disclosure.

It should be noted that, in order to facilitate the description and clearly illustrate the steps of the semiconductor structure manufacturing method,FIGS.1to4in this embodiment are partial structural schematic diagrams of the semiconductor structure.

FIGS.1to4, the semiconductor structure includes: a substrate100and a data line110on the substrate100, the data line110extends along a first direction X; a first transistor101on the data line110and a first transistor101and the second transistor102on the side of the first transistor101away from the data line110; wherein, both the first transistor101and the second transistor102include: a semiconductor column103, and the semiconductor column103is located on a part of the top surface of the data line110and along the third direction Z extends; there is an isolation structure133inside the semiconductor column103, along the second direction Y, the thickness of the isolation structure133in different regions is different in the third direction Z, and the isolation structure133runs through the semiconductor column103, and two of the first direction X, the second direction Y and the third direction Z intersect.

It can be understood that the first transistor101can be used as a dynamic memory selection transistor, and the second transistor102can be used as a structure for storing data, that is, the role of a capacitor structure, so that via the first transistor101and the second transistor102the storage or reading operation of data is realized, and the second transistor102has a smaller size than the current capacitor structure, which is conducive to further reducing the overall size of the semiconductor structure. Moreover, the second transistor102is smaller than the current capacitor structure. The capacitive structure has a higher sensitivity to the current change in the first transistor101, which is conducive to realizing the storage or reading operation of data within a smaller current change range, thereby helping to reduce the power consumption of the semiconductor structure during operation.

The embodiments of the present disclosure will be described in more detail below in conjunction with the accompanying drawings.

In some embodiments, the material type of the substrate100may be an elemental semiconductor material or a crystalline inorganic compound semiconductor material. The elemental semiconductor material can be silicon or germanium; the crystalline inorganic compound semiconductor material can be silicon carbide, silicon germanium, gallium arsenide or gallium indium.

In some embodiments, the data line110can be a bit line, and the substrate100, the bit line and the semiconductor column103have the same semiconductor element, and the substrate100, the bit line and the semiconductor column103can use the same film layer structure Formed, the film layer structure is composed of semiconductor elements, so that the semiconductor column103and the bit line are integrated, thereby improving the interface state defects between the semiconductor column103and the bit line, so as to improve the performance of the semiconductor structure.

Wherein, the semiconductor element may include one of silicon, carbon, germanium, arsenic, gallium, and indium. In one example, both the bit line and the semiconductor column103include silicon.

In some embodiments, the material of the data line110may also include a metal-semiconductor compound, and the metal-semiconductor compound has a relatively small resistivity compared to an unmetallized semiconductor material. Therefore, as far as the semiconductor columns103are concerned, the resistivity of the data lines110is smaller, which is beneficial to reduce the resistance of the data lines110and the contact resistance between the data lines110and the semiconductor columns103, further improving the electrical performance of the semiconductor structure. Taking silicon as the semiconductor element as an example, the metal-semiconductor compound may include one of cobalt silicide, nickel silicide, molybdenum silicide, titanium silicide, tungsten silicide, or tantalum silicide.

In some embodiments, a plurality of data lines110arranged at intervals may be formed on the substrate100, and each data line110may be in contact with one semiconductor column103. In FIGS. There are 4 data lines110spaced apart from each other, and each data line110is in contact with4semiconductor columns103as an example. In practical applications, the number of data lines110and the number of semiconductor columns103that contacts the data line110can be reasonably set according to actual electrical requirements.

In some embodiments, the third direction Z may be a direction in which the substrate100points to the data line110.

In some embodiments, referring toFIG.3, the semiconductor column103has opposite first sides a and second sides b in the second direction Y, a direction Y1pointing to the inside of the semiconductor column103along the first side a, and Along the direction Y2of the second side b pointing to the inside of the semiconductor column103, the thickness of the isolation structure133in the third direction Z gradually decreases.

It can be understood that the isolation structure133may be formed by performing thermal oxidation treatment on part of the semiconductor column103. During the thermal oxidation treatment, as time goes by, the less the area of the column103is converted into the isolation structure133, the more the thickness of the isolation structure133gradually decreases in the third direction Z along the direction Y1and the direction Y2.

In addition, the isolation structure133performs in-situ thermal oxidation treatment on a part of the semiconductor column103, which is different from the top surface oxidation process and the oxidation deposition process. The in-situ oxidation treatment on the sidewall of the semiconductor column103is beneficial to form the isolation structure133penetrating the semiconductor column103, and is beneficial to improve the density of the isolation structure133. Moreover, along the direction Y1and the direction Y2, the thickness of the isolation structure133in the third direction Z gradually decreases, which is beneficial to reduce the electron density. The probability of tunneling improves the device performance of semiconductor structures.

In some embodiments, referring toFIG.1toFIG.3, the semiconductor column103located on the side of the isolation structure133close to the data line110is the first semiconductor column113, and the first transistor101includes the first semiconductor column113; the first transistor101further includes: a gate structure111extending along the second direction Y and surrounding a part of the sidewall of the first semiconductor column113,

In some embodiments, referring toFIG.1toFIG.4, the gate structure111includes: a gate dielectric layer121, surrounding a part of the sidewall of the first semiconductor column113extending along the third direction Z; a gate131, extending along the third direction Z; two directions Y extend and surround the gate dielectric layer121away from the sidewall of the first semiconductor column113. It can be understood that the gate structure111corresponds to a plurality of first semiconductor columns113arranged at intervals along the second direction Y.

In some embodiments, referring toFIG.1toFIG.4, the semiconductor column103located on the side of the isolation structure133away from the data line110is the second semiconductor column123, and the second transistor102includes the second semiconductor column123; the second transistor102further includes: a first conductive layer112located on part of the sidewall of the second semiconductor column123extending along the third direction Z; a second conductive layer122located on the top surface of the second semiconductor column123away from the data line110; a dielectric A layer132is located between the first conductive layer112and the second semiconductor column123, and between the second conductive layer122and the second semiconductor column123.

The dielectric layer132and the first conductive layer112will be described in detail below through two specific embodiments.

In some embodiments, referring to4ainFIG.4, the dielectric layer132surrounds the sidewall of the second semiconductor column123extending along the third direction Z, and the first conductive layer112extends along the second direction Y and surrounds the dielectric layer.132is away from the sidewall of the second semiconductor column123. It can be understood that the first conductive layer112extends along the second direction Y, and the first conductive layer112corresponds to a plurality of second semiconductor columns123arranged at intervals along the second direction Y. In this way, it is beneficial to simplify the preparation process of the first conductive layer112, and to control the second semiconductor column123or detect the conductivity of the second semiconductor column123at different times through the same first conductive layer112,

In some other embodiments, referring to4binFIG.4, the dielectric layer132is located only on the two opposite sidewalls of the second semiconductor column123along the second direction Y, and the first conductive layer112is located away from the dielectric layer132. The two sidewalls of the second semiconductor column123, so that one first conductive layer112corresponds to one second semiconductor column123, and the two opposite sidewalls of the second semiconductor column123are connected to the first isolation layer along the first direction X.114for contact connection, and the first isolation layer114will be described in detail later. In addition, in practical applications, the dielectric layer132can surround the sidewalls of the second semiconductor column123extending along the third direction Z, and the first conductive layer112is only located on the two opposite sidewalls of the dielectric layer132along the second direction Y.

In some embodiments, the second conductive layer122extends along the first direction X, and the second conductive layer122corresponds to a plurality of semiconductor columns103arranged at intervals along the first direction X. In this way, it is beneficial to simplify the preparation process of the second conductive layer122, and to control the second semiconductor column123or detect the conductivity of the second semiconductor column123at different times through the same second conductive layer122.

In some embodiments, if the second transistor102is in an on state, the second semiconductor column123facing the first conductive layer112and facing the second conductive layer122constitutes the channel of the second transistor102region, the first conductive layer112, the second conductive layer122and the channel region constitute the transmission path of the conduction current of the second transistor102. It can be understood that since the first conductive layer112is located on the sidewall of the second semiconductor column123extending along the third direction Z, the second conductive layer122is located on the top surface of the second semiconductor column123away from the substrate100, that is, the first conductive layer112and the second conductive layer122are not located in the same plane, so that the conduction current is not transmitted in a plane, but transmitted in a three-dimensional space.

In one example, referring toFIG.3, the transmission path of conduction current enters the second semiconductor column123through the first conductive layer112through the dielectric layer132, and turns in the second semiconductor column123, and passes through the dielectric layer132into the second conductive layer122. In this way, the entire second semiconductor column123can be used as a channel region when the second transistor102is in the on state.

In some embodiments, the first conductive layer112can be used as the source electrode of the second transistor102, and the second conductive layer122can be used as the drain electrode of the second transistor102. In some other embodiments, the first conductive layer112may also serve as the drain of the second transistor102, and the second conductive layer122may also serve as the source of the second transistor102,

In some embodiments, the second transistor102includes a single electron transistor (SET, single electron transistor). Part of the first semiconductor column113in the first transistor101that is in contact with the isolation structure133is used as the gate of the second transistor102. When the single-electron transistor works, only a small amount of electrons is needed, so that the gate of the second transistor102generates a small voltage. When the voltage changes, the single-electron transistor can sensitively and accurately sense the difference in the voltage at the gate of the second transistor102, which is beneficial to improve the first transistor102to the part of the first transistor101that is in contact with the isolation structure133. The sensing sensitivity of the current change in the semiconductor column113makes the second transistor102have extremely low power consumption and extremely high switching speed. Understandably, single-electron transistors have the advantages of small size, high speed, high sensitivity, and most importantly, low power consumption compared to conventional transistors.

In addition, the second transistor102has a smaller volume than the current capacitor structure, which is beneficial to further reduce the overall size of the semiconductor structure.

In some embodiments, referring toFIGS.1to3, the dielectric layer132includes a first dielectric layer142and a second dielectric layer152, and the first dielectric layer142is located between the first conductive layer112and the second semiconductor column123. Between, the second dielectric layer152is located between the second conductive layer122and the second semiconductor column123; along the third direction Z, the average value of the thickness of the isolation structure133is the first thickness, and the thickness of the second dielectric layer152is the second thickness along the second direction Y, the thickness of the first dielectric layer142is a third thickness, the first thickness is greater than the second thickness, and the first thickness is greater than the third thickness T3.

It should be noted that, in some embodiments, the first dielectric layer142and the second dielectric layer152can be integrally formed, that is, the first dielectric layer142and the second dielectric layer152are formed by the same preparation process, and the dielectric layer132is a whole. InFIGS.1to3, the first dielectric layer142and the second dielectric layer152are taken as an example; in other embodiments, the first dielectric layer142and the second dielectric layer152can be It is a different film layer structure, that is, the dielectric layer132is a multilayer structure.

In some embodiments, the second thickness is equal to the third thickness. In one example, the first thickness may be 5 nm, and the second and third thicknesses may be about 1 nm.

In some embodiments, referring toFIG.1toFIG.3, along the third direction Z, the first semiconductor column113includes a first region I, a second region II, and a third region III arranged in sequence; wherein, the first region I is in contact with the data line110, the gate structure111surrounds the sidewall of the second region II extending along the third direction Z, and the third region III is in contact with the isolation structure133; the projection the positive side of the third region III on the substrate100is a first orthographic projection, and the orthographic projection of the second semiconductor column123on the substrate100is a second orthographic projection, and the second orthographic projection is located in the first orthographic projection.

It can be understood that the second region II facing the gate structure111can be used as a channel region when the first transistor101is in an on state, and the gate structure111and the first semiconductor column113can form a GAA transistor, that is, the first transistor101may be a GAA transistor, and the data line110is located between the substrate100and the GAA transistor, so that a 3D stacked storage device can be formed, which is beneficial to increase the integration density of the semiconductor structure.

In some embodiments, the dielectric layer132may be obtained by performing thermal oxidation treatment on the surface of the second semiconductor column123, that is, the part of the second semiconductor column123at the periphery of the second semiconductor column123is converted into a dielectric layer132. In this way, the orthographic projection of the second semiconductor column123on the substrate100, that is, the second orthographic projection is reduced, so that the second orthographic projection is located in the first orthographic projection.

In some embodiments, the orthographic projection of the second region II on the substrate100is smaller than the orthographic projection of the third region III on the substrate100, and smaller than the orthographic projection of the first region I on the substrate100, perpendicular to In the section in the third direction Z, it is beneficial to form the second region II with a smaller cross-sectional area, and it is beneficial to improve the control ability of the gate structure111surrounding the sidewall of the second region II on the second region II, so that it is easier to control GAA transistors turned on or off. In other embodiments, the orthographic projections of the first region, the second region, and the third region on the substrate can be equal; or, the orthographic projections of the second region and the third region on the substrate are smaller than the first region on the substrate. orthographic projection.

In some embodiments, the first semiconductor column113is doped with dopant ions, and the dopant ions doped in the first region I and the third region III are of the same type, and the dopant ions doped in the second region II, the type of doping ions is different from the type of doping ions doped in the first region I, so it is beneficial to improve the electrical performance of the first transistor101, for example, improving the conductivity of the first region I and the third region III and improving the first region I The on/off ratio of zone II. Wherein, the dopant ions include N-type ions and P-type ions. Specifically, the N-type ions may include one of arsenic ions, phosphorus ions or antimony ions; the P-type ions may include one of boron ions, indium ions or gallium ions.

In some embodiments, the gate structure111includes: a gate dielectric layer121located on a part of the sidewall extending along the second direction Y and surrounding the first semiconductor column113; a gate131surrounding the gate dielectric layer121away from the first One side of the second semiconductor column123; along the second direction Y, the thickness of the gate dielectric layer121is the fourth thickness, and the thickness of the dielectric layer132between the first conductive layer112and the second semiconductor column123is the third thickness, the fourth thickness is greater than the third thickness.

It can be understood that the first transistor101can be a GAA transistor, the second transistor102can be a single-electron transistor, and a part of the third region III in the first transistor101that is in contact with the isolation structure133constitutes the second gate of transistor102. In the single-electron transistor, the thickness of the dielectric layer132corresponding to the first conductive layer112and the second conductive layer is very thin, about 1 nm, to ensure the high performance of the single-electron transistor; the thickness of the gate dielectric layer121between the second region II is relatively large, about 5 nm-10 nm, so as to ensure the high performance of the GAA transistor. In this way, making the fourth thickness greater than the third thickness is beneficial to improve the overall electrical performance of the first transistor101and the second transistor102,

In addition, in the first transistor101, the region in the gate structure111that is in contact with the channel region II can be formed by performing thermal oxidation treatment on the surface of the channel region II, that is, the area on the periphery of the channel region III Part of the channel region III is transformed into a part of the gate structure; in the second transistor102, the dielectric layer132can be obtained by thermal oxidation treatment on the surface of the second semiconductor column123, or can be formed on the surface of the second semiconductor column123obtained by the deposition process; and, the fourth thickness is greater than the third thickness. In this way, the orthographic projection of the second region II on the substrate100is located at the orthographic projection of the second semiconductor column123on the substrate100.

In some embodiments, with reference toFIG.1toFIG.3, semiconductor structure also comprises:

The first isolation layer114is located between the adjacent first conductive layers112along the first direction X, and the first isolation layer114is used to realize the adjacent first conductive layers112along the first direction X.

The second isolation layer124covers the side of the first conductive layer112away from the substrate100, the second isolation layer124and the first conductive layer112jointly cover the side wall of the dielectric layer132extending along the third direction X, the second isolation layer124is used to protect the first conductive layer112and prevent other electrical structures in the semiconductor structure from causing electrical interference to the first conductive layer112.

The third isolation layer134is located between the adjacent gate structures111along the first direction X, and is used to realize electrical isolation between the adjacent gate structures111along the first direction X.

The fourth isolation layer144surrounds the sidewalls extending in the third direction Z of the third region III, and is used to realize the electrical isolation between two adjacent third zones III either in the first direction X or in the second direction Y.

It should be noted that the first isolation layer114, the second isolation layer124, the third isolation layer134and the fourth isolation layer144can be a single-layer structure or a multi-layer structure, for clarity of illustration,FIGS.1to3only schematically show the outlines of the above four isolation layers. In addition, in practical applications, in order to realize the electrical isolation between various adjacent conductive structures in the semiconductor structure, the division and setting of the isolation layer can be determined according to the actual needs and the actual manufacturing process.FIGS.1to3are only the above-mentioned example of a total isolation layer consisting of four isolation layers.

In addition, for clarity of illustration, inFIGS.1to3, the first isolation layer114and the third isolation layer134are illustrated in the same filling manner, and the second isolation layer124is illustrated in another filling manner. In practical applications, two of the first isolation layer114, the second isolation layer124, the third isolation layer134and the fourth isolation layer144may be made of the same material. In one example, the materials of the first isolation layer114, the second isolation layer124, the third isolation layer134and the fourth isolation layer144can be one of silicon nitride or silicon oxynitride.

In some embodiments, referring toFIGS.1to3, when the fourth isolation layer144surrounds the sidewall of the third region III extending along the third direction Z, a fourth isolation layer144corresponds to a third region III, so that the adjacent fourth isolation layer144has a first gap in the first direction X, and has a second gap in the second direction Y, and the first gap and the second gap are connected; the third isolation layer134along the second direction Y extends and fills the first gap; the semiconductor structure further includes:

The first insulating layer115is located between adjacent data lines110along the second direction Y, and surrounds the sidewalls of the first region I extending along the third direction Z, so as to achieve Electrical isolation between adjacent data lines110in Y, and electrical isolation between adjacent first regions I in the first direction X or in the second direction Y.

The second insulating layer125fills the second gap, so as to improve the electrical insulation effect between adjacent third regions III along the second direction Y.

The third insulating layer135extends along the second direction Y and is located between adjacent isolation structures133along the second direction Y, and the third isolation layer is also located between adjacent isolation structures133along the first direction X. between the third insulating layer135to improve the stability of the semiconductor structure.

It should be noted that, in practical applications, at least two of the materials of the first insulating layer115, the second insulating layer125and the third insulating layer135may be the same. In one example, the materials of the first insulating layer115, the second insulating layer125and the third insulating layer135can all be silicon oxide. In addition, the first insulating layer115, the second insulating layer125, and the third insulating layer135can all be of a single-layer structure or a multi-layer structure with the outer contour of the insulating layer. In addition, in practical applications, in order to realize the electrical isolation between various adjacent conductive structures in the semiconductor structure and the overall stability of the semiconductor structure, the division and setting of the insulating layer can be determined according to the actual needs and the actual preparation process, as shown inFIG.1toFIG.3are only examples of the overall insulating layer composed of the above three insulating layers.

In addition, for clarity of illustration, inFIGS.1to3, the gate131, the first conductive layer112and the second conductive layer122are shown in the same filling manner. In practical applications, the materials of two of the first conductive layer112and the second conductive layer122in the gate131may be the same, or the first conductive layer112and the second conductive layer122have different conductive materials. In one example, the materials of the gate131, the first conductive layer112and the second conductive layer122can all be titanium nitride.

In summary, the first transistor101can be used as a dynamic memory selection transistor, and the second transistor102can be used as a structure for storing data, that is, the role of a capacitor structure, so that the storage or read operation of data can be realized in the first transistor101and the second transistor102together, and the first transistor101can be a GAA transistor, which is beneficial to improve the integration density of the semiconductor structure. Compared with the current capacitor structure, the second transistor102has a smaller size, which is beneficial to overall size of the semiconductor structure is further reduced, and the second transistor102has a higher sensitivity to the current change in the first transistor101than the current capacitor structure, which is beneficial to realize data processing within a smaller current change range. storage or read operations, thereby helping to reduce power consumption when the semiconductor structure is working.

Another embodiment of the present disclosure further provides a method for controlling reading and writing of a semiconductor structure, which is used for controlling the semiconductor structure provided by an embodiment of the present disclosure. A method for controlling reading and writing of a semiconductor structure provided by another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.FIG.5is a flow chart of a method for controlling reading and writing of a semiconductor structure provided by another embodiment of the present disclosure.

With reference toFIG.1toFIG.5, the read-write control method of semiconductor structure comprises the steps:

S101: Provide a semiconductor structure according to an embodiment of the present disclosure.

Wherein, the semiconductor column103on the side of the isolation structure133close to the data line110is the first semiconductor column113, the semiconductor column103on the side of the isolation structure133away from the data line110is the second semiconductor column123, the first semiconductor column123Part of the area of the column113that is in contact with the isolation structure133is the storage node143,

In some embodiments, the storage node143may be a part of the third region III.

The second transistor102includes: a first conductive layer112located part of the sidewall of the second semiconductor column123extending along the third direction Z; a second conductive layer122located at the side of the second semiconductor column123away from the data line110top surface. In some embodiments, the first conductive layer112may be the source of the second transistor102, and the second conductive layer122may be the drain of the second transistor102,

S102: Turning on the first transistor101to adjust the voltage at the storage node143, so as to realize the write operation to the storage node143.

It can be understood that the voltage at the first region I is affected by the data line110, and when the first transistor101is turned on, the first region I and the third region III are turned on, so that the voltage at the third region III of the voltage at the storage node143is changed under the influence of the first region I, so as to adjust the voltage at the storage node143to realize the write operation to the storage node143, In one example, the data line110transmits a high level to the first region I, and when the first transistor101is turned on, the voltage at the third region III also becomes a high level, so that the voltage at the storage node143also becomes is at a high level, at this time, the storage node143is equivalent to storing data “1”.

S103: Apply a first voltage to one of the first conductive layer112and the second conductive layer122.

S104: Detect the voltage at another of the first conductive layer112and the second conductive layer122which the first voltage is not applied to as the second voltage, determined the conductivity of the second semiconductor column123by the difference between the second voltage and the first voltage, wherein the conductivity of the second semiconductor column determines the voltage at the storage node143, so as to realize the read operation on the storage node143.

In some embodiments, the first voltage is applied to the first conductive layer112, and the voltage at the second conductive layer122is detected as the second voltage. It can be understood that the voltage at the storage node143determines the conductivity of the second semiconductor column123, the greater the voltage at the storage node143, the greater the conductivity of the second semiconductor column123will be. Based on the difference in the conductivity of the second semiconductor column123, under the premise that the value of the first voltage remains unchanged, the value of the detected second voltage is different. The higher the conductivity of the second semiconductor column123is, the higher the second voltage will be, and the value of will be closer to the value of the first voltage. Therefore, the conductivity of the second semiconductor column123can be determined based on the difference between the second voltage and the first voltage, the smaller the difference between the second voltage and the first voltage, the greater the conductivity of the second semiconductor column123is; and the voltage at the storage node143is larger.

In one example, if the voltage at the storage node143is at a high level, the conductivity of the second semiconductor column123is high, and the value of the detected second voltage is close to the value of the first voltage, that is, if the difference of the second voltage from the first voltage is small, it is determined that the data read at this time is “1”, so as to realize the read operation on the storage node143.

In some embodiments, along the third direction Z, the first transistor101includes sequentially arranged first region I, second region II and third region III, and surrounds the second region II along the third direction Z. The extended sidewall gate structure111, the first region I is in contact with the data line110, the third region III is in contact with the isolation structure133, and the third region III is the storage node143; the write operation to the storage node143is realized. Including: applying a third voltage to the data line110, applying a fourth voltage to the gate structure111, so as to conduct the transmission path between the first region I and the third region III, so that the voltage at the third region III is influenced by the voltage on the data line110, thus to realize the write operation to the third region III.

It can be understood that the third voltage applied to the data line110is the voltage to be stored at the storage node143, and the fourth voltage applied to the gate structure111is to make the first transistor101turn on state voltage.

In some embodiments, the first transistor101can be a GAA transistor, then the fourth voltage with a smaller value can be used to make the first transistor101in a conduction state, and the second transistor102can be a single-electron transistor, then the stored voltage at the node143has a small change, there will be a difference between the second voltage and the first voltage. Therefore, using the first transistor101and the second transistor102to realize the write operation and read operation of data is beneficial to reduce power consumption when the semiconductor structure is in operation.

To sum up, using the semiconductor structure provided by an embodiment of the present disclosure to realize the write operation and read operation of data is beneficial to realize the storage or read operation of data within a smaller range of voltage variation, thereby it is beneficial to reduce the power consumption when the semiconductor structure is working.

Another embodiment of the present disclosure further provides a method for manufacturing a semiconductor structure, which is used to prepare the semiconductor structure provided in an embodiment of the present disclosure. A method for manufacturing a semiconductor structure provided by another embodiment of the present disclosure will be described in detail below with reference toFIGS.1to27. Corresponding to each step of the manufacturing method are structural schematic diagrams of the semiconductor structure disclosed inFIGS.6to27. It should be noted that the parts that are the same as or corresponding to the foregoing embodiments will not be repeated here. In addition, in order to facilitate the description and clearly illustrate the steps of the semiconductor structure manufacturing method,FIGS.6to27are partial structural schematic diagrams of the semiconductor structure.

Wherein,FIG.8is a schematic cross-sectional view of the structure shown inFIG.7along the first cross-sectional direction AA1, andFIG.9is a schematic cross-sectional view of the structure shown inFIG.7along the second cross-sectional direction BB1. It should be noted that one or both of the schematic cross-sectional view along the first cross-sectional direction AA1and the schematic cross-sectional view along the second cross-sectional direction BB1will be provided later according to the needs of the expression. When only one drawing is referred to, the drawing is along a schematic cross-sectional view of the first cross-sectional direction AA1; when referring to two drawings at the same time, the drawings are first a schematic cross-sectional view along the first cross-sectional direction AA1, and second is a schematic cross-sectional view along the second cross-sectional direction BB1.

Referring toFIG.1toFIG.27, the manufacturing method of semiconductor structure comprises the steps:

An initial substrate is provided, and the material type of the initial substrate may be an elemental semiconductor material or a crystalline inorganic compound semiconductor material. The elemental semiconductor material can be silicon or germanium; the crystalline inorganic compound semiconductor material can be silicon carbide, silicon germanium, gallium arsenide or gallium indium.

With reference toFIGS.6to11, a data line110and a first transistor101are formed in the initial substrate, the data line110extends along the first direction X, one end of the first transistor101is connected to the data line110, and the remaining initial substrate as the substrate100.

In some embodiments, forming the data line110and the first transistor101in the initial substrate may include the following steps:

Referring toFIG.6, the initial substrate is patterned to form data lines110extending along the first direction X and arranged at intervals along the second direction Y, and to form initial semiconductor columns153located on part of the top surface of the data lines110; the original substrate remained as the substrate100.

In some embodiments, the process of patterning the initial substrate to form the data lines110and the initial semiconductor columns153may be divided into etching the initial substrate twice. In the first etching, the initial substrate is etched using a first mask layer having a plurality of first openings that are mutually separated and extend along the first direction X, and the length of the first openings is the same as that of the subsequently formed data lines. The length is the same, so as to form a plurality of first grooves extending along the first direction X; form an initial fourth insulating layer that fills the first grooves; the second mask layer of the second opening extending in the direction Y etches the initial substrate and the initial fourth insulating layer, and the length of the second opening is consistent with the length of the subsequently formed gate structure, so as to form a plurality of gate structures along the second direction. The Y-extending second trench108leaves the original fourth insulating layer as the fourth insulating layer145.

In some embodiments, referring toFIG.7toFIG.9, along the third direction Z, the initial semiconductor column153includes an initial first region163, an initial second region173and an initial third region183arranged in sequence; Before forming the gate structure111, the manufacturing method further includes the following steps:

Forming an initial fifth insulating layer, the initial fifth insulating layer is located on the sidewall of the second trench108extending along the third direction Z, and the initial fifth insulating layer located on the sidewall of the second trench108has the third trench; referring toFIG.7, an initial third isolation layer154filling the third trench is formed; the initial fifth insulating layer and the fourth insulating layer145that are in contact with the initial third region183are removed to expose the initial third region along all sidewalls extending in the third direction Z; an initial fourth isolation layer164covering all sidewalls extending in the third direction Z of the initial third region is formed, and the initial fourth isolation layer164extends along the second direction A through hole f is formed between adjacent initial third regions183on Y, and the through hole f exposes part of the top surface of the fourth insulating layer145.

Wherein, continuing to refer toFIG.7toFIG.9, the initial third isolation layer154and the initial fourth isolation layer164together form a supporting framework, and the initial fifth insulating layer and the initial fifth insulating layer shown inFIG.6are etched with the supporting framework as a mask. The remaining initial fifth insulating layer is used as the fifth insulating layer155. Referring toFIG.7, between the initial first regions163adjacent in the direction Y, the fifth insulating layer155extends along the second direction Y, and is located between the initial first regions163adjacent in the first direction X. Wherein, the fourth insulating layer145and the fifth insulating layer155inFIG.7jointly constitute the first insulating layer115, and the initial first region163subsequently serves as the first region of the first semiconductor column.

In addition, the supporting frame is in contact with the initial third region183, and part of the supporting frame is embedded in the first insulating layer115. In the step of etching the initial fifth insulating layer and the fourth insulating layer145, on the one hand, the supporting frame plays a role of supporting and fixing the initial semiconductor column153, when the etching process produces a pressing force on the initial semiconductor column153, it is beneficial to prevent the initial semiconductor column153from being tilted or shifted due to extrusion, so as to improve the stability of the semiconductor structure; three zone183damage. After forming the first insulating layer115, a third gap g is formed between the initial second region173and the initial third isolation layer154, the through hole f and the third gap g together form a cave structure h, and the initial second region173is subsequently formed as the second region of the first semiconductor column.

Referring toFIG.10andFIG.11, a gate structure111is formed, the gate structure111extends along the second direction Y and surrounds part of the sidewall of the initial semiconductor column153, and part of the initial semiconductor column153and the gate structure111constitute the first transistor101.

In some embodiments, the step of forming the gate structure111includes: forming a first sacrificial layer109on the top surface of the initial third region183away from the substrate100; the exposed sidewall of the third gap g, that is, the sidewall of the initial second region173extending along the third direction Z, is thermally oxidized to form the gate dielectric layer121, and the gap between the gate dielectric layer121and the initial third isolation layer154is a fourth gap extending along the second direction Y; a gate131filling the fourth gap is formed, and the gate dielectric layer121and the gate131together constitute the gate structure111.

Continuing to refer toFIG.11, an initial second insulating layer165filling the through hole f is formed, the initial second insulating layer165is the basis for subsequent formation of the second insulating layer, and the first sacrificial layer109is removed.

It should be noted that the above-mentioned embodiment is only an example of forming the first transistor101, and the manufacturing method provided by another embodiment of the present disclosure does not limit the forming method of the first transistor101, for example, the gate dielectric layer can also be formed by a deposition process.

With reference toFIGS.12to27, a second transistor102is formed on the side of the first transistor101away from the data line110; wherein, the first transistor101and the second transistor102include: a semiconductor column103, a semiconductor column103Located on part of the top surface of the data line110and extending along the third direction Z; the semiconductor column103has an isolation structure133inside, along the second direction Y, the thickness of the isolation structure133in different regions is different in the third direction Z, and the isolation structure133runs through the semiconductor column103, and two of the first direction X, the second direction Y and the third direction Z intersect.

The formation of the isolation structure133and the second transistor102will be described in detail below.

In some embodiments, along the third direction Z, the initial semiconductor column153includes a first region I, a second region II, a third region III, a fourth region IV and a fifth region V arranged in sequence, and the gate pole structure111surrounds the sidewall extending along the third direction Z of the second region II. It can be understood that, with reference toFIG.11andFIG.12, the first zone I is the initial first zone163, the second zone II is the initial second zone173, the third zone III, the fourth zone IV and the fifth zone V collectively constitute an initial third region183,

Referring toFIG.12toFIG.18, the step of forming the isolation structure133includes: forming a protective layer106on the sidewalls of the first region I, the third region III and the fifth region V extending along the third direction Z, exposing only the side walls of the fourth region IV extend along the third direction Z.

In some embodiments, forming protective layer106comprises the following steps:

Referring toFIGS.10to13, the initial third isolation layer154and the initial fourth isolation layer164are etched to expose the side walls of the fourth region IV and the fifth region V extending along the third direction Z; the initial third isolation layer154remains as part of the third isolation layer134and the initial fourth isolation layer164remains as the fourth isolation layer144,

Referring toFIG.12andFIG.13, a second sacrificial layer119is formed, the second sacrificial layer119is located on the sidewalls of the fourth region IV and the fifth region V extending along the third direction Z, and the initial second insulating layer165is in contact with the second sacrificial layer119, and has a fifth gap i, the fifth gap i extends along the second direction Y.

Referring toFIG.14, a fifth isolation layer174filling the fifth gap i is formed.

Referring toFIG.15andFIG.16, the second sacrificial layer119and the initial second insulating layer165are etched with the fifth isolation layer174and the semiconductor column103as a mask, and the remaining second sacrificial layer119only surrounds the first sidewall of the fourth region IV extends along the third direction Z, and the remaining initial second insulating layer165is located between the adjacent fourth isolation layers144along the second direction Y, and is located between the adjacent fourth isolation layers144along the second direction Y. between the two sacrificial layers119. In some embodiments, the material of the second sacrificial layer119and the material of the initial second insulating layer165may be the same, and the second sacrificial layer119and the initial second insulating layer165may be etched simultaneously through the same etching process. In practical applications, the material of the second sacrificial layer119may also be different from that of the initial second insulating layer165, and the material of the second sacrificial layer119and the initial second insulating layer165are respectively etched by different etching processes.

Referring toFIGS.17to18, a third sacrificial layer129is formed, the third sacrificial layer129surrounds the sidewall of the fifth region V extending along the third direction Z, and the third sacrificial layer129is in contact with the fifth isolation layer174; using the third sacrificial layer129, the semiconductor column103and the fifth isolation layer174as a mask, removing the remaining second sacrificial layer119, and removing the initial second insulating layer165between two adjacent second sacrificial layer119located along the second direction Y (refer toFIG.16), and the remaining initial second insulating layer165is used as the second insulating layer125to form the protective layer106on the exposed sidewall of the fourth region IV which extends along the third direction Z and the sixth gaps k.

It can be understood that the protection layer106may include: a first insulating layer115surrounding the sidewall extending in the third direction Z of the first region I, and a first insulating layer115surrounding the sidewall extending in the third direction Z of the third region III. The fourth isolation layer144, and the third sacrificial layer129surrounding the sidewall of the fifth region V extending along the third direction Z. In addition, in the step of etching the second sacrificial layer119and the initial second insulating layer165, the third sacrificial layer129and the fifth isolation layer174may also serve as a supporting frame.

Referring toFIG.19toFIG.20, the exposed sidewall of the fourth region IV is oxidized to convert the fourth region IV into an isolation structure133, leaving the initial semiconductor column153as the semiconductor column103; the semiconductor column103on the side of the structure133close to the data line110is the first semiconductor column113, the semiconductor column103on the side of the isolation structure133away from the data line110is the second semiconductor column123, the first region I, the second region II and the third region III forms the first semiconductor column113, and the fifth region V serves as the second semiconductor column123.

In some embodiments, oxidizing the exposed sidewall of the fourth zone IV includes: performing an in-situ steam generation process (ISSG) on the exposed sidewall of the fourth zone IV. The in-situ water vapor generation process is a process for growing an oxide layer through a high-temperature water vapor atmosphere, and the growth rate of the oxide layer is relatively fast. The oxide layer obtained by oxidation has better electrical properties.

In some embodiments, referring toFIGS.21to26, after forming the isolation structure133, the step of forming the second transistor102may include: forming the first conductive layer112, the dielectric layer132and the second conductive layer122; the first conductive layer112is located on part of the sidewall of the second semiconductor column123extending along the third direction Z, the second conductive layer122is located on the top surface of the second semiconductor column123away from the data line110, and the dielectric layer132is located on the first conductive layer.112and the second semiconductor column123, and between the second conductive layer122and the second semiconductor column123.

In some embodiments, forming the dielectric layer132on the surface of the exposed second semiconductor column123includes: performing oxidation treatment on the exposed second semiconductor column123, so as to form a dielectric layer132on the surface of the remaining second semiconductor column123. In some embodiments, the exposed second semiconductor columns123may be oxidized by an in-situ water vapor generation process.

In some embodiments, forming the dielectric layer132may include the following steps:

Referring toFIGS.21to22, part of the protective layer106of the sidewall of the second semiconductor column123extending along the third direction Z is removed to expose part of the sidewall of the second semiconductor column123extending along the third direction Z, and expose the side of the second semiconductor column123away from the isolation structure133.

In some embodiments, before removing part of the protective layer106on the sidewall of the second semiconductor column123extending along the third direction Z, it further includes: referring toFIGS.21to22, forming a initial third insulating layer175is the basis for the subsequent formation of the third insulating layer135.

Continuing to refer toFIGS.21to22, the step of removing part of the protective layer106on the sidewalls of the second semiconductor columns123extending along the third direction Z includes: removing the sidewalls extending along the third direction Z surrounding the fifth region V, the third sacrificial layer129of the wall, and the fifth isolation layer174between the adjacent third sacrificial layers129along the first direction X is removed, and the remaining fifth isolation layer174is located between the adjacent third sacrificial layers129along the first direction X. Between the initial third insulating layer175, it can be understood that, in the structure shown inFIG.21, the fifth isolation layer174and the initial third isolation layer154together constitute the third isolation layer134(refer toFIG.1).

Referring toFIG.23toFIG.24, a fourth sacrificial layer139is formed, the fourth sacrificial layer139is located on the sidewall of the fifth region V extending along the third direction Z, and the fourth sacrificial layer139and the initial third insulating layer175contact connection, the seventh gap between adjacent fourth sacrificial layers139along the first direction; continue referring toFIG.23toFIG.24, forming the first isolation layer114filling the seventh gap.

Referring toFIG.25andFIG.26, using the first isolation layer114and the second semiconductor column123as a mask, the fourth sacrificial layer139and part of the initial third insulating layer175(refer toFIG.24) are removed, and the removed initial third insulating layer175are located between adjacent fourth sacrificial layers139along the second direction Y, and the original third insulating layer175remains as the third insulating layer135.

Continuing to refer toFIG.25andFIG.26, a dielectric layer132is formed on the exposed surface of the second semiconductor column123. It should be noted that the dielectric layer132can be formed in the direction of oxidizing the exposed surface of the second semiconductor column123, or can be formed by deposition process to form the dielectric layer132on the exposed surface of the second semiconductor column123.

It should be noted that the dielectric layer132can be integrally formed, and the first conductive layer112, the second isolation layer124, and the second conductive layer122are subsequently formed on the basis ofFIG.25andFIG.26,

In some other embodiments, the dielectric layer132can be formed in steps, and the step-by-step formation of the dielectric layer132will be described in detail below.

The second semiconductor column123is exposed except for the side surface in contact with the isolation structure133, and the protective layer106is located on other surfaces of the second semiconductor column123; after the second semiconductor column123is formed, the protective layer106is removed Previously, the method further includes: forming a first isolation layer114extending along the second direction Y, the first isolation layer114being located between adjacent second semiconductor columns123arranged at intervals along the first direction X. The method of forming the first isolation layer114has been described in the foregoing embodiments, and will not be repeated here.

The dielectric layer132includes a first dielectric layer142and a second dielectric layer152, the first dielectric layer142is located between the first conductive layer112and the second semiconductor column123, and the second dielectric layer152is located in the second conductive layer122Between the second semiconductor column123; forming the first dielectric layer142, the first conductive layer112and the second dielectric layer152includes the following steps:

Referring toFIG.27, an initial first dielectric layer162is formed on the surface of the exposed second semiconductor column123, and the first isolation layer114and the initial first dielectric layer162form a first interval; an initial first dielectric layer162is formed in the first interval. A conductive layer172, the initial first conductive layer172fills the first gap and is located on the side of the initial first dielectric layer162away from the second semiconductor column123.

With reference toFIG.27,FIG.2andFIG.4, the initial first conductive layer172is etched back, and the remaining initial first conductive layer172is used as the first conductive layer112. In the step of etching back, remove the second semiconductor column123far away from the initial first dielectric layer162on the top surface of the isolation structure, it should be noted that, the process of forming the initial first dielectric layer162and the second dielectric layer152can be one of ISSG or deposition process.

Continuing to refer toFIG.2andFIG.4, the second conductive layer122is formed on the side of the second dielectric layer152away from the substrate100, and the second conductive layer extends along the first direction X.

To sum up, in the semiconductor structure formed by the manufacturing method provided by another embodiment of the present disclosure, the first transistor101can be used as a dynamic memory selection transistor, and the second transistor102can be used as a structure for storing data, that is, as a capacitor structure. In this way, the storage or read operation of data can be realized through the first transistor101and the second transistor102, and the first transistor101can be a GAA transistor, which is beneficial to improve the integration density of the semiconductor structure, and the second transistor102has a smaller size than the current capacitor structure, which is conducive to further reducing the overall size of the semiconductor structure. Moreover, the second transistor102has a higher resistance to current changes in the first transistor101than the current capacitor structure. The inductive sensitivity is conducive to realizing the storage or reading operation of data within a smaller range of current change, thereby helping to reduce the power consumption of the semiconductor structure when it is working.

Those of ordinary skill in the art can understand that the above-mentioned implementations are specific examples for realizing the disclosure, and in practical applications, various changes can be made to it in form and details without departing from the disclosure spirit and scope of the embodiments. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the protection scope of the embodiments of the present disclosure should be based on the scope defined in the claims.