CN106653609B - A kind of novel fin formula field effect transistor and preparation method thereof - Google Patents

Abstract

The invention discloses a novel fin field effect transistor and a manufacturing method thereof. The novel fin field effect transistor of the present invention comprises: a base; a fin located on the base, a source region and a The drain region; across the upper surface of the fin in the middle of the source region and the drain region and the gate structure on both sides, the upper surface of the fin has a convex tooth structure, and the convex part of the convex tooth structure is a tooth, so There is a mobility enhanced region between the two teeth on the upper surface of the fin, the source region and the drain region are not doped at the top of the teeth, and the gate structure is embedded in the protruding tooth structure of the fin. The present invention can Increase transistor drive current and improve transistor performance.

Description

A novel fin field effect transistor and its manufacturing method

technical field

The invention relates to the technical field of semiconductors, in particular to a fin field effect transistor and a manufacturing method thereof.

technical background

Transistors are critical components in integrated circuits. To meet the demands of faster transistors, higher drive currents are required. In addition, since the driving current of the transistor is proportional to the gate width of the transistor, in order to increase the driving current, a larger gate width is required.

The fin field effect transistor has a narrow semiconductor material active region protruding from the base as a fin, the fin includes a source region and a drain region at both ends, the gate structure includes a gate dielectric layer and a gate electrode on the gate dielectric layer, The gate structure spans the fin between the source region and the drain region, and forms a conductive channel in contact with its upper surface and both sides, which is equivalent to increasing the gate width, effectively increasing the driving current, and improving device performance. With the advancement of existing related technologies, the feature size of the device is further reduced, and the process needs to be further improved to further increase the driving current.

Contents of the invention

The object of the present invention is to provide a novel manufacturing method of a fin field effect transistor, increase the driving current of the transistor, and improve the performance of the transistor.

Another object of the present invention is to provide a fin field effect transistor fabricated by the above method.

To achieve the above object, the present invention adopts the following technical solutions:

A method for manufacturing a novel fin field effect transistor, comprising the following steps:

(1) providing a base, and forming a semiconductor protrusion structure on the base;

(2) making and etching the semiconductor protruding structure through the first mask to form a fin with a convex tooth structure on the upper surface, and the convex part of the convex tooth structure is a tooth;

(3) Depositing a mobility enhancement region different from the lattice constant of the fin on the surface of the fin not covered by the first mask;

(4) Make a second mask, the second mask covers the middle of the fin, and at the same time use the first mask and the second mask as masks to dope impurities to both ends of the fin to form a source region and drain region, and removing the second mask and the first mask;

(5) Make a third mask covering the source region and the drain region. The opening edges at both ends of the third mask are projected on the undoped middle fin, and the third mask is used to form the embedded The gate structure in the protruding tooth structure of the fin portion is removed, and the third mask plate is removed.

Preferably, the substrate is silicon (Si) or silicon-on-insulator (SOI).

Preferably, the mobility enhanced region is silicon germanium (GeSi) or silicon carbide (SiC).

Preferably, the step (3) adopts the epitaxial growth method to deposit the mobility enhanced region.

Preferably, the doping of impurities in step (4) is done by ion implantation.

Preferably, during step (4) ion implantation and doping, the implantation direction is not perpendicular to the first mask.

Preferably, during step (4) ion implantation doping, the implantation is performed at a certain angle towards the direction of the source region or the drain region, and then implanted at a certain angle towards the opposite direction.

Preferably, in step (5), the edges of the openings at both ends of the third mask plate are on the teeth of the undoped middle fin.

Preferably, in step (5), the edges of the openings at both ends of the third mask plate are on the center of the teeth on the undoped middle fin.

A novel Fin Field Effect Transistor, comprising: a base; a fin located on the base, a source region and a drain region are formed at both ends of the fin; an upper surface of the fin spanning the middle of the source region and the drain region As well as the gate structures on both sides, the upper surface of the fin has a convex tooth structure, the convex part of the convex tooth structure is a tooth, and there is a mobility enhanced region between the two teeth on the upper surface of the fin, the The source region and the drain region are not doped at the top of the tooth portion, and the gate structure is embedded in the protruding tooth structure of the fin portion.

Compared with the prior art, the present invention has the following beneficial effects:

The first mask plate of the fin field effect transistor manufacturing method of the present invention is firstly used as a mask to form a fin with a convex tooth structure on the upper surface, secondly used as a mask for the formation process of the mobility enhancement region, and then used as a partial mask for impurity doping , realize multiple effective utilization of the first mask plate, make the process flow simple and easy to realize, and save the process cost.

In the transistor produced by the present invention, the upper surface of the fin has a convex tooth structure, and a mobility enhancement region with a lattice constant different from that of the fin is formed between the two teeth on the upper surface of the fin, and compressive stress or tensile stress is introduced to increase For the mobility of fin carriers, the conduction current when the transistor is turned on is improved; the gate structure is embedded in the protruding tooth structure of the fin, which increases the gate width and further improves the drive current of the transistor; in addition , the source region and the drain region are not doped at the top of the teeth, which increases the surface resistance of the source region and the drain region, reduces the leakage current between the gate and the source region and the drain region, and further optimizes the performance of the transistor.

Description of drawings

Fig. 1-Fig. 5 is the structural schematic diagram of the manufacturing process of the embodiment of the present invention;

6 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 7 is a partial schematic diagram of a gate structure according to an embodiment of the present invention.

Detailed ways

The present invention will be introduced below in conjunction with the accompanying drawings and embodiments, and the embodiments are only used to explain the present invention and do not limit the present invention in any way.

Figures 1-5 are schematic structural diagrams of each step in the manufacturing process of the embodiment of the present invention. As shown in the figure, the manufacturing method of the novel fin field effect transistor includes the following steps:

(1) As shown in FIG. 1 , a substrate 100 is provided, and a semiconductor protrusion structure 201 is formed on the substrate;

The material of the base 100 can be silicon-on-insulator (SOI), at this time the top silicon layer of the SOI is used to form the protruding structure 201; the material of the base 100 can also be silicon (Si), germanium (Ge), silicon germanium ( GeSi) or silicon carbide (SiC) and other semiconductor substrates. At this time, the protruding structure 201 is formed by etching the above-mentioned semiconductor substrate. The insulating dielectric layer of the structure 201; the material of the base 100 can also be an insulating substrate such as silicon oxide, at this time, the protruding structure 201 is formed by an epitaxial process, and the material of the fin 200 can be silicon (Si), germanium (Ge), silicon Germanium (GeSi) or silicon carbide (SiC), the preferred substrate of the embodiment of the present invention is silicon (Si) or silicon-on-insulator (SOI). The accompanying drawings use silicon-on-insulator (SOI) as an example.

(2) As shown in FIG. 2 , fabricate and etch the semiconductor protruding structure 201 through the first mask plate 10 to form a fin 200 with a convex tooth structure on the upper surface, and the convex part of the convex tooth structure is a tooth portion 210 ;

The first mask plate 10 is first used as a mask to form the fin portion 200 with a convex tooth structure on the upper surface.

(3) As shown in FIG. 3 , deposit a mobility enhancement region 300 having a lattice constant different from that of the fin 200 on the surface of the fin 200 not covered by the first mask 10 ;

The portion not covered by the first mask plate 10 in the embodiment of the present invention, the groove wall and groove bottom of the groove between the two tooth portions 210 formed by etching leak out the semiconductor material of the fin portion 200, and the mobility enhancement can be deposited by epitaxial growth. In region 300, when the embodiment substrate is silicon (Si) or silicon-on-insulator (SOI), the material of fin 200 is silicon, germanium or carbon has a different lattice constant from silicon, and the silicide of germanium or carbon is easy to epitaxially grow on the silicon surface , so the mobility enhanced region 300 is preferably silicon germanium (GeSi) or silicon carbide (SiC).

(4) As shown in Figure 4, make a second mask 20, the second mask 20 covers the middle of the fin, and at the same time use the first mask 10 and the second mask 20 as masks to cover the fins. Doping impurities at both ends of 200 to form a source region 400 and a drain region 500, and then removing the second mask 20 and the first mask 10;

In the embodiment of the present invention, the first mask 10 and the second mask 20 are used as masks for doping, and the second mask 20 covers the middle of the fin, so an undoped region is formed in the middle of the fin 200, so that Before reaching the threshold voltage, the transistor is turned off; due to the coverage of the first mask 10, when doping impurities to both ends of the fin portion 200 to form the source region 400 and the drain region 500, the source region 400 and the drain region 500 There is no doping at the top of the tooth portion 210. The doping impurities in the embodiment of the present invention are n-type impurities such as phosphorus or arsenic or p-type impurities such as phosphorus. The doping method is preferably ion implantation doping. The first mask plate 10 is vertical, implanted at a certain angle to the direction of the source region or the drain region, and then implanted at a certain angle to the opposite direction, so as to form a continuous doped region in the entire source region 400 and drain region 500. The size of the undoped region at the top of the portion 210 can be adjusted by the height of the teeth and the implantation angle during ion implantation.

(5) As shown in FIG. 5 , make a third mask 30 covering the source region 400 and the drain region 500 , and the opening edges at both ends of the third mask 30 are projected on the undoped middle fin 200 , The gate structure 600 embedded in the protruding tooth structure of the fin portion 200 is formed through the third mask 30 , and then the third mask 30 is removed.

Preferably, the opening edges at both ends of the third mask 30 are on the tooth portion 210 on the undoped middle fin portion 200, since there is no mobility enhancement region 300 on the tooth portion 210, the carrier mobility Weak, to reduce the gate leakage current, preferably, the opening edges at both ends of the third mask 30 are on the center of the teeth 210 on the undoped middle fin 200, and the center of the teeth 210 carriers The mobility is the weakest, so it is better to reduce the gate leakage current.

The fin field effect transistor of the embodiment of the present invention manufactured by the above method includes: a substrate 100; a fin 200 located on the substrate 100, and a source region 400 and a drain region 500 are formed at both ends of the fin 200; The upper surface of the fin 200 in the middle of the source region 400 and the drain region 500 and the gate structures 600 on both sides, the upper surface of the fin 200 has a convex tooth structure, and the convex part of the convex tooth structure is a tooth portion 210. There is a mobility enhancement region 300 between the two tooth portions 210 on the upper surface of the fin portion 200, the source region 400 and the drain region 500 are not doped at the top of the tooth portion 210, and the gate structure 600 is embedded in the convex portion of the fin portion 200. within the tooth structure.

As shown in Fig. 6 and Fig. 7, the fin field effect transistor of the embodiment of the present invention, the upper surface of the fin 200 has a convex tooth structure, and the lattice constant formed between the two teeth 210 on the upper surface of the fin 200 is different from that of the fin. The mobility enhancement region 300 of 200 introduces compressive stress or tensile stress, increases the mobility of carriers to the fin 200, and improves the conduction current when the transistor is turned on; the gate structure 600 is embedded in the raised portion of the fin. In the tooth structure, the gate width is increased to further increase the driving current of the transistor; in addition, the source region 400 and the drain region 500 are not doped at the top of the tooth portion 210, which increases the surface resistance of the source region 400 and the drain region 500, which is common knowledge in the field. The source region 400 of the transistor is electrically connected to the source electrode, and the drain region 500 is electrically connected to the drain electrode, so the leakage current between the gate, the source electrode and the drain electrode can be reduced, and the performance of the transistor can be further optimized.

Claims (10)

1. a kind of production method of novel fin formula field effect transistor, which comprises the following steps:

(1) substrate is provided, and forms semiconductor projective structure on the substrate；

(2) it makes and the semiconductor projective structure is etched by the first mask plate, form the fin that upper surface is in double wedge structure, The double wedge structure convex portion is teeth portion；

(3) in the fin portion surface deposition and fin lattice constant difference Enhanced mobility area not covered by the first mask plate；

(4) the second mask plate is made, the second mask plate covers among fin, while being with the first mask plate and the second mask plate Phosphorus or arsenic p-type impurity or n-type impurity are adulterated in exposure mask, Xiang Suoshu fin both ends, form source region and drain region, source region and drain region are in tooth Portion top non-impurity-doped, and remove the second mask plate and the first mask plate；

(5) production covering source region and drain region third mask plate, the third mask plate both ends open edge projection not by On the fin of the centre of doping, the gate structure being embedded in the double wedge structure of the fin is formed by third mask plate, and go Except third mask plate.

2. the production method of novel fin formula field effect transistor according to claim 1, it is characterised in that: the substrate is Silicon or silicon-on-insulator.

3. the production method of novel fin formula field effect transistor according to claim 2, it is characterised in that: the mobility Enhancement region is SiGe or silicon carbide.

4. the production method of novel fin formula field effect transistor according to claim 1, it is characterised in that: (3) step is adopted Enhanced mobility area is deposited with epitaxial growth method.

5. the production method of novel fin formula field effect transistor according to claim 1, it is characterised in that: (4) step is mixed Impurity uses ion implantation doping.

6. the production method of novel fin formula field effect transistor according to claim 5, it is characterised in that: (4) step from When son injection doping, injection direction is not vertical with the first mask plate.

7. the production method of novel fin formula field effect transistor according to claim 6, it is characterised in that: (4) step from When son injection doping, it is first biased to source region or the angled injection in drain region direction, then note angled in the opposite direction partially Enter.

8. the production method of novel fin formula field effect transistor according to claim 1, it is characterised in that: (5) step institute Third mask plate both ends open edge is stated in the teeth portion on the fin of undoped centre.

9. the production method of novel fin formula field effect transistor according to claim 8, it is characterised in that: (5) step institute Third mask plate both ends open edge is stated on the teeth portion center on the fin of undoped centre.

10. a kind of novel fin formula field effect transistor, comprising: substrate；Fin in the substrate, fin both ends shape At source region and drain region；The gate structure of fin upper surface and two sides among the source region and drain region, it is characterised in that: The fin upper surface is in double wedge structure, and the double wedge structure convex portion is teeth portion, between two teeth portion of fin upper surface There are Enhanced mobility area, in teeth portion top non-impurity-doped, the gate structure is embedded in the fin for the source region and drain region In double wedge structure.