Semiconductor device and method for manufacturing the same
11508848 · 2022-11-22
Assignee
- Semiconductor Manufacturing International (Beijing) Corporation (Beijing, CN)
- Semiconductor Manufacturing International (Shanghai) Corporation (Shanghai, CN)
Inventors
Cpc classification
H01L29/66545
ELECTRICITY
H01L29/517
ELECTRICITY
H01L29/6653
ELECTRICITY
H01L29/785
ELECTRICITY
H01L21/28105
ELECTRICITY
H01L29/165
ELECTRICITY
H01L29/4983
ELECTRICITY
International classification
H01L21/28
ELECTRICITY
H01L29/165
ELECTRICITY
H01L29/66
ELECTRICITY
H01L29/49
ELECTRICITY
Abstract
The present disclosure teaches semiconductor devices and methods for manufacturing the same. Implementations of the semiconductor device may include: a semiconductor substrate; a semiconductor fin positioned on the semiconductor substrate; and a gate structure positioned on the semiconductor fin, where the gate structure includes a gate dielectric layer on a part of a surface of the semiconductor fin and a gate on the gate dielectric layer; where the gate includes a metal gate layer on the gate dielectric layer and a semiconductor layer on a side surface of at least one side of the metal gate layer; and where the semiconductor layer includes a dopant, where a conductivity type of the dopant is the opposite of a conductivity type of the semiconductor fin. The present disclosure can improve a work function of the device, thereby improving a current characteristic of the device during a working process, reducing the short channel effect (SCE), and lowering a leakage current.
Claims
1. A semiconductor device, comprising: a semiconductor substrate; a semiconductor fin positioned on the semiconductor substrate; and a gate structure positioned on the semiconductor fin; wherein the gate structure comprises a gate dielectric layer on a part of a surface of the semiconductor fin and a gate on the gate dielectric layer; wherein the gate comprises a metal gate layer on the gate dielectric layer and a semiconductor layer on a side surface of at least one side of the metal gate layer; and wherein the semiconductor layer comprises a dopant, where a conductivity type of the dopant is the opposite of a conductivity type of the semiconductor fin.
2. The semiconductor device according to claim 1, wherein: the conductivity type of the semiconductor fin is N-type, the conductivity type of the dopant is P-type, and the dopant comprises boron; or the conductivity type of the semiconductor fin is P-type, the conductivity type of the dopant is N-type, and the dopant comprises phosphorus or arsenic.
3. The semiconductor device according to claim 1, wherein a doping density of the dopant ranges from 1×10.sup.20 atoms/cm.sup.3 to 1×10.sup.21 atoms/cm.sup.3.
4. The semiconductor device according to claim 1, wherein the semiconductor layer is located on each side surface of two sides of the metal gate layer.
5. The semiconductor device according to claim 1, wherein a material of the semiconductor layer comprises polysilicon or amorphous silicon.
6. The semiconductor device according to claim 1, further comprising: a spacer layer on each side surface of two sides of the gate structure; and an inter-layer dielectric layer surrounding the spacer layer and the gate structure.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings forming a part of the specification describe embodiments and implementations of the present disclosure, and are used together with the specification to explain the principles of the present disclosure.
(2) Referring to the accompanying drawings, the present disclosure can be understood more clearly according to the detailed description below, where:
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DETAILED DESCRIPTION
(17) Various exemplary embodiments and implementations of the present disclosure are described in detail with reference to the accompanying drawings herein. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and values described in these embodiments and implementations do not limit the scope of the present disclosure.
(18) In addition, it should be understood that, for ease of description, the sizes of various parts shown in the accompanying drawings are not drawn according to an actual proportional relation.
(19) The following description of at least one exemplary embodiment or implementation is merely illustrative and should in no way serve as a limitation to the disclosure and application or use thereof.
(20) Technologies, methods, and devices known to a person of ordinary skill in the related art may not be discussed in detail, but the technologies, methods, and devices should be considered as a part of the authorized specification in appropriate cases.
(21) In all of the examples shown and discussed herein, any specific value should be interpreted merely as an example, rather than a limitation. Therefore, other examples of the exemplary embodiments and implementations may have different values.
(22) It should be noted that, similar reference numbers and letters represent similar terms in the following accompanying drawings, and therefore, an item does not need to be further discussed in subsequent accompanying drawings once the item is defined in an accompanying drawing.
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(24) As shown in
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(26) In some implementations, the conductivity type of the semiconductor fin 22 may be N-type (that is, a to-be-formed semiconductor device may be a P-channel metal oxide semiconductor (PMOS) device), and the conductivity type of the dopant may be P-type. For example, the dopant may include boron. In other implementations, the conductivity type of the semiconductor fin 22 may be P-type (that is, a to-be-formed semiconductor device may be an N-channel metal oxide semiconductor (NMOS) device), and the conductivity type of the dopant may be N-type. For example, the dopant may include phosphorus or arsenic.
(27) In some implementations, a doping density of the dopant may range from 1×10.sup.20 atoms/cm.sup.3 to 1×10.sup.21 atoms/cm.sup.3. For example, the doping density of the dopant may be 3×10.sup.20 atoms/cm.sup.3, 5×10.sup.20 atoms/cm.sup.3, or 8×10.sup.20 atoms/cm.sup.3.
(28) Optionally, as shown in
(29) It should be noted that, a dotted line in
(30) Returning to
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(32) Optionally, the method may further include: forming, respectively on two sides of the pseudo gate structure by using an epitaxial growth process, a source 361 and a drain 362 that are at least partially located in the semiconductor fin. The spacer layer 35 separately isolates the source 361 and the drain 362 from the semiconductor layer 232. The conductivity type of the dopant of the semiconductor layer 232 is the same as conductivity types of the source 361 and the drain 362. In some implementations, a multilayer spacer layer may be formed in a process of forming the spacer layer, thereby increasing the distance between the source/drain and a gate and reducing parasitic capacitance between the source/drain and the gate.
(33) Returning to
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(35) In some implementations, a contact etch stop layer (CESL) (not shown in the figure) may be deposited on the semiconductor structure on which the source and the drain have been epitaxially grown, and subsequently, the inter-layer dielectric layer is deposited.
(36) Returning to
(37)
(38) As shown in
(39) Subsequently, as shown in
(40) Subsequently, the mask layer 51 is removed to form a structure shown in
(41) It should be noted that, in steps of
(42) Returning to
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(44) Hereto, implementations of a method for manufacturing a semiconductor device are provided. In the described implementations of the manufacturing method, the semiconductor layer is partially etched to remove the part of the semiconductor layer, so as to form the opening on which the gate dielectric layer is exposed. Subsequently, the opening is filled with the metal gate layer so that the formed semiconductor device includes the doped semiconductor layer on the side surface of at least one side of the metal gate layer. The conductivity type of the dopant included in the semiconductor layer is the opposite of the conductivity type of the semiconductor fin. This can improve a work function of the device, thereby improving a current characteristic of the device during a working process, reducing the SCE, and lowering a leakage current. In addition, implementations of the foregoing method can further effectively resolve the inconformity of a metal gate process in a small-sized device, and in particular, the edge effect.
(45) According to forms of the foregoing manufacturing method, a semiconductor device is formed. As shown in
(46) In forms of this implementation, the semiconductor device includes the doped semiconductor layer on the side surface of at least one side of the metal gate layer, and the conductivity type of the dopant included in the semiconductor layer is the opposite of the conductivity type of the semiconductor fin. This can improve a work function of the device, thereby improving a current characteristic of the device during a working process, reducing the SCE, and lowering a leakage current. In addition, this can further effectively resolve the inconformity of a metal gate process in a small-sized device, and in particular, the edge effect.
(47) In some implementations, the conductivity type of the semiconductor fin 22 may be N-type (that is, the semiconductor device may be a PMOS device), and the conductivity type of the dopant may be P-type. For example, the dopant may include boron. Therefore, for a PMOS device (the conductivity type of the semiconductor fin 22 is N-type), the conductivity type of the dopant is P-type (that is, the dopant is a P-type dopant). This can enable the Fermi level of the semiconductor layer 232 to be closer to a valence band, thereby increasing a work function of the PMOS device. A greater work function value of the PMOS device indicates a greater capability to improve a current characteristic of the device during a working process, reduce the SCE, and lower a leakage current, and the inconformity of a metal gate process in a small-sized device can be effectively resolved, and in particular, the edge effect.
(48) In other implementations, the conductivity type of the semiconductor fin 22 may be P-type (that is, the semiconductor device may be an NMOS device), and the conductivity type of the dopant may be N-type (that is, the dopant is an N-type dopant). For example, the dopant may include phosphorus or arsenic. Therefore, for an NMOS device (the conductivity type of the semiconductor fin 22 is P-type), the conductivity type of the dopant is N-type. This can enable the Fermi level of the semiconductor layer 232 to be closer to a valence band, thereby decreasing a work function of the NMOS device. A smaller work function value of the NMOS device indicates a greater capability to improve a current characteristic of the device during a working process, reduce the SCE, and lower a leakage current, and the inconformity of a metal gate process in a small-sized device can be effectively resolved, and in particular, the edge effect.
(49) In some implementations, a doping density of the dopant may range from 1×10.sup.20 atoms/cm.sup.3 to 1×10.sup.21 atoms/cm.sup.3. For example, the doping density of the dopant may be 3×10.sup.20 atoms/cm.sup.3, 5×10.sup.20 atoms/cm.sup.3, or 8×10.sup.20 atoms/cm.sup.3.
(50) In some implementations, as shown in
(51) In some implementations, as shown in
(52) In some implementations, as shown in
(53) In some implementations, the manufacturing method may further include: before filling the opening with a metal gate layer, metalizing the remaining part of the semiconductor layer to form a metal silicide layer.
(54)
(55) As shown in
(56) Subsequently, as shown in
(57) Forms of the foregoing implementations utilize a process of metalizing the remaining part of the semiconductor layer 232 to form the metal silicide layer 96.
(58) Subsequently, as shown in
(59) Above, additional implementations of a method for manufacturing a semiconductor device are provided. In these implementations, after the opening is formed by partially etching the semiconductor layer, the remaining part of the semiconductor layer is metalized to form the metal silicide layer. Subsequently, the opening is filled with the metal gate layer. Metalizing the remaining part of the semiconductor layer to form the metal silicide layer can further improve a work function of the semiconductor device, thereby further improving a current characteristic of the device during a working process, reducing the SCE, and lowering a leakage current, and the inconformity of a metal gate process in a small-sized device can be further effectively resolved, and in particular, the edge effect.
(60) In implementations of the foregoing manufacturing method, a semiconductor device is formed. As shown in
(61) In foregoing implementations, the semiconductor device includes the metal silicide layer on the side surface of at least one side of the metal gate layer, and the conductivity type of the dopant included in the metal silicide layer is the opposite of the conductivity type of the semiconductor fin. This can further improve a work function of the device, thereby improving a current characteristic of the device during a working process, reducing the SCE, and lowering a leakage current. In addition, this can further effectively resolve the inconformity of a metal gate process in a small-sized device, and in particular, the edge effect.
(62) In some implementations, the conductivity type of the semiconductor fin 22 may be N-type (that is, the semiconductor device may be a PMOS device), and the conductivity type of the dopant may be P-type. For example, the dopant may include boron.
(63) In other implementations, the conductivity type of the semiconductor fin 22 may be P-type (that is, the semiconductor device may be an NMOS device), and the conductivity type of the dopant may be N-type. For example, the dopant may include phosphorus or arsenic.
(64) In some implementations, a doping density of the dopant may range from 1×10.sup.20 atoms/cm.sup.3 to 1×10.sup.21 atoms/cm.sup.3. For example, the doping density of the dopant may be 3×10.sup.20 atoms/cm.sup.3, 5×10.sup.20 atoms/cm.sup.3, or 8×10.sup.20 atoms/cm.sup.3.
(65) In some implementations, as shown in
(66) Similar to the semiconductor device shown in
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(71) As can be learned from the foregoing curve diagrams of relationships, a more greatly-improved work function of the semiconductor device (for example, the PMOS device has a greater work function or the NMOS device has a smaller work function) indicates a weaker leakage current and a better characteristic of a working current of the device, so that the SCE can be reduced and the performance of the semiconductor device can be improved.
(72) Hereto, implementations of methods for manufacturing a semiconductor device and implementations of formed semiconductor devices according to the present disclosure are described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the foregoing descriptions, a person skilled in the art will understand how to implement the technical solution disclosed herein.
(73) Although some particular embodiments and implementations of the present disclosure have been described in detail by using examples, a person skilled in the art will understand that the foregoing examples are merely for the purpose of description and are not intended to limit the scope of the present disclosure. A person skilled in the art will understand that the foregoing embodiments and implementations may be modified without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is subjected to the appended claims.