Semiconductor device and method of forming a semiconductor device

Abstract

The application relates to the field of semiconductors and discloses a semiconductor device and a forming method of the semiconductor device. The semiconductor device comprises a substrate, a source region and a drain region, and a halo injection region. The halo injection region comprises a first halo injection sub-region for preventing direct channel penetration and a second halo injection sub-region for adjusting junction leakage current. The first halo injection sub-region covers the bottom and / or side of a preset region, the preset region comprising the source region and / or the drain region, and a depletion layer ends in the first halo injection sub-region. The second halo injection sub-region covers the bottom and / or side of the first halo injection sub-region, and a minority carrier diffusion layer ends in the second halo injection sub-region. The doping concentration of the second halo injection sub-region is greater than that of the first halo injection sub-region. The semiconductor device provided by the application can adjust the interface performance between the substrate and the source region and / or the drain region by setting the halo injection region, and can solve the contradiction between direct channel penetration and pn junction leakage.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and particularly to a semiconductor device and a method for forming a semiconductor device. Background Technology

[0002] Most existing metal-oxide-semiconductor (MOSFET) field-effect transistors (FETs) employ halo ion implantation to avoid source / drain depletion region merging and direct channel punch-through. However, excessively high halo doping concentrations can lead to BTBT (inter-band tunneling) and the generation of electron-hole pairs during depletion, ultimately resulting in increased pn junction leakage in the FET. Conversely, decreasing the halo doping concentration can increase minority carrier diffusion flux at the pn interface region, further increasing pn junction leakage.

[0003] Therefore, resolving the contradiction between direct channel penetration and PN junction leakage is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This invention discloses a semiconductor device and a method for forming the semiconductor device, which can resolve the contradiction between direct channel penetration and pn junction leakage.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] According to a first aspect of this disclosure, a semiconductor device is provided, comprising:

[0007] Substrate;

[0008] A source region and a drain region are formed within the substrate, and a channel region is formed between the source region and the drain region; one of the drain region and the substrate is p-type and the other is n-type, the source region and the drain region are of the same type, and a depletion layer is formed between the source region or the drain region and the substrate;

[0009] A halo injection region is formed between the substrate and a predetermined region, the predetermined region including the source region and / or the drain region; the halo injection region includes a first halo injection sub-region for preventing direct channel penetration and a second halo injection sub-region for regulating junction leakage current, wherein:

[0010] The first halo injection sub-region covers the bottom and / or sides of the preset region; the depletion layer terminates within the first halo injection sub-region;

[0011] The second halo injection sub-region covers the bottom and / or side of the first halo injection sub-region, and the diffusion layer formed by minority carrier diffusion on one side of the substrate terminates in the second halo injection sub-region. The doping concentration of the second halo injection sub-region is greater than that of the first halo injection sub-region.

[0012] In one embodiment of this disclosure, the doping concentration of the first halo injection sub-region and the thickness of the first halo injection sub-region covering the preset region are used as structural parameters to prevent direct channel penetration.

[0013] The doping concentration of the second halo injection sub-region and the thickness of the second halo injection sub-region covering the first halo injection sub-region are used as structural parameters for adjusting the junction leakage current.

[0014] In one embodiment of this disclosure, the doping concentration range of the first halo implantation sub-region is 1×e 11 ions / cm 2 ~1×e 13 ions / cm 2 .

[0015] In one embodiment of this disclosure, the doping concentration of the second halo-ring implanted sub-region is in the range of 1×e 13 ions / cm 2 ~1×e 16 ions / cm 2 .

[0016] In one embodiment of this disclosure, the edge of the depletion layer is spaced from the edge of the first halo injection sub-region on the side closer to the substrate.

[0017] In one embodiment of this disclosure, the semiconductor device further includes a gate structure formed on the substrate surface and located on the channel region.

[0018] In one embodiment of this disclosure, the gate structure includes a gate dielectric layer formed on the surface of the substrate and a gate conductive material layer formed on the side of the gate dielectric layer opposite to the substrate.

[0019] According to a first aspect of this disclosure, a method for forming a semiconductor device is provided, comprising:

[0020] Provide a substrate;

[0021] A source region and a drain region are formed within the substrate, and a channel region is formed between the source region and the drain region; one of the drain region and the substrate is p-type and the other is n-type, the source region and the drain region are of the same type, and a depletion layer is formed between the source region or the drain region and the substrate;

[0022] Define a first doped region, perform a first ion implantation to form a first halo implantation sub-region to prevent direct channel penetration, the first halo implantation sub-region covering the bottom and / or sides of a preset region, the preset region including the source region and / or the drain region; terminate the depletion layer within the first halo implantation sub-region;

[0023] Define a second doped region, perform a second ion implantation to form a second halo ring implantation sub-region for adjusting junction leakage current, the second halo ring implantation sub-region covers the bottom and / or side of the first halo ring implantation sub-region; terminate the diffusion layer formed by minority carrier diffusion on one side of the substrate within the second halo ring implantation sub-region, and control the doping concentration of the second halo ring implantation sub-region to be greater than the doping concentration of the first halo ring implantation sub-region;

[0024] The first halo injection sub-region and the second halo injection sub-region form a halo injection region.

[0025] In one embodiment of this disclosure, prior to performing the first ion implantation, the method further includes:

[0026] Determine the doping concentration of the first halo implantation sub-region;

[0027] Determine the doping depth of the first halo implantation sub-region.

[0028] In one embodiment of this disclosure, the method for determining the doping concentration of the first halo implantation sub-region includes:

[0029] A first comparison device group is formed, and each first comparison device in the first comparison device group is configured to include a first halo ring injection sub-region. The doping concentration of the first halo ring injection sub-region in each first comparison device is controlled to be different, and the doping depth of the first halo ring injection sub-region in each first comparison device is controlled to be the same.

[0030] Each of the first comparison devices in the first comparison device group is adjusted to the off state, and the source and drain voltages of the first comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping concentration of the first comparison device with the smallest substrate current is taken as the doping concentration of the first halo ring injection sub-region.

[0031] In one embodiment of this disclosure, the method for determining the doping depth of the first halo implantation sub-region includes:

[0032] A second comparison device group is formed, and each second comparison device in the second comparison device group is set to include a first halo ring implantation sub-region. The doping depth of the first halo ring implantation sub-region in each second comparison device is controlled to be different, and the doping concentration of the first halo ring implantation sub-region in each second comparison device is controlled to be the same.

[0033] Each of the second comparison devices in the second comparison device group is adjusted to the off state, and the source and drain voltages of the second comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the second comparison device with the smallest substrate current is taken as the doping depth of the first halo ring implantation sub-region.

[0034] In one embodiment of this disclosure, the method for determining the doping depth of the first halo implantation sub-region includes:

[0035] Estimate the depletion layer depth on one side of the first halo injection sub-region by estimating the abrupt junction between the preset region and the substrate;

[0036] Based on the estimated value, the doping depth of the first halo injection sub-region is adjusted so that the doping depth is greater than or equal to the estimated value.

[0037] In one embodiment of this disclosure, the depletion layer depth on one side of the first halo-injected sub-region of the abrupt junction between the preset region and the substrate is estimated using the following formula:

[0038]

[0039] Where: d B_eq Indicates the depth of the depletion layer; X e_D X represents the electron concentration in the preset region. p_B n represents the hole concentration in the substrate. i This indicates the intrinsic semiconductor carrier concentration.

[0040] In one embodiment of this disclosure, prior to performing the second ion implantation, the method further includes:

[0041] Determine the doping concentration of the second halo implantation sub-region;

[0042] Determine the doping depth of the second halo implantation sub-region.

[0043] In one embodiment of this disclosure, the method for determining the doping concentration of the second halo implanted sub-region includes:

[0044] Adjust the ion concentration in the second doping region and determine the doping critical value when the ions in the second doping region are supersaturated.

[0045] Based on the doping threshold, the doping concentration of the second halo injection sub-region is controlled to be less than the doping threshold.

[0046] In one embodiment of this disclosure, the method for determining the doping depth of the second halo implantation sub-region includes:

[0047] A third comparison device group is formed, and each third comparison device in the third comparison device group is configured to include a first halo ring injection sub-region and a second halo ring injection sub-region. The doping depth of the second halo ring injection sub-region in each third comparison device is controlled to be different, and the doping concentration of the second halo ring injection sub-region in each third comparison device is controlled to be the same.

[0048] Each of the third comparison devices in the third comparison device group is adjusted to the off state, and the source and drain voltages of the third comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the third comparison device with the smallest substrate current is taken as the doping depth of the second halo ring implantation sub-region.

[0049] In the semiconductor device disclosed herein, a source region and a drain region are formed in a substrate, and a channel region is formed between the source region and the drain region. A halo injection region is formed in the substrate and located around the source region and / or drain region to improve leakage current. Specifically, a first halo injection sub-region covers the bottom and / or side of a predetermined region, which includes the source region and / or drain region. The depletion layer terminates within the first halo injection sub-region, which can prevent the phenomenon of direct channel penetration. At the same time, a second halo injection sub-region covers the bottom and / or side of the first halo injection sub-region. The diffusion layer formed by minority carrier diffusion on one side of the substrate terminates within the second halo injection sub-region, and the doping concentration of the second halo injection sub-region is greater than that of the first halo injection sub-region. The second halo injection sub-region can reduce the concentration gradient between the first halo injection sub-region it covers and the substrate, which can reduce the possibility of pn junction leakage and reduce junction leakage current.

[0050] It should be noted that the semiconductor device provided in this disclosure can adjust the interface performance between the substrate and the source and / or drain regions by setting a halo injection region. Specifically, the first halo injection sub-region can avoid channel punch-through, and the second halo injection sub-region can reduce junction leakage current, thereby achieving simultaneous optimization of channel punch-through phenomenon and pn junction leakage phenomenon. Attached Figure Description

[0051] Figure 1 A simplified schematic diagram of the structure of a semiconductor device provided in the embodiments of this disclosure;

[0052] Figure 2 This is a schematic diagram of the leakage current path in a semiconductor device.

[0053] Figure 3 A schematic diagram of the structure of a semiconductor device provided in an embodiment of this disclosure;

[0054] Figure 4 This is another schematic diagram of the structure of a semiconductor device provided in an embodiment of this disclosure;

[0055] Figure 5A flowchart illustrating a method for forming a semiconductor device according to an embodiment of this disclosure.

[0056] Icons: 100, Substrate; 200, Source region; 300, Drain region; 400, Halo injection region; 410, First halo injection sub-region; 420, Second halo injection sub-region; 500, Gate structure; 510, Gate dielectric layer; 520, Gate conductive material layer. Detailed Implementation

[0057] Typical embodiments embodying the features and advantages of this disclosure will be described in detail in the following description. It should be understood that this disclosure can have various variations in different embodiments without departing from the scope of this disclosure, and the descriptions and drawings therein are illustrative in nature and not intended to limit this disclosure.

[0058] In the following description of various exemplary embodiments of this disclosure, reference is made to the accompanying drawings, which form part of this disclosure, and which illustrate by way of example different exemplary structures, systems, and steps that may implement various aspects of this disclosure. It should be understood that other specific embodiments of the components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of this disclosure. Furthermore, while the terms “above,” “between,” “within,” etc., may be used in this specification to describe different exemplary features and elements of this disclosure, these terms are used herein only for convenience, such as according to the orientation of the examples in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of this disclosure.

[0059] In a first aspect, embodiments of this disclosure provide a semiconductor device. Figure 1 This is a schematic diagram of the structure of a semiconductor device provided in an embodiment of this disclosure. Figure 1 The structure shown indicates that the semiconductor device includes:

[0060] A source region 200 and a drain region 300 are formed within a substrate 100, and a channel region is formed between the source region 200 and the drain region 300; one of the drain region 300 and the substrate 100 is p-type and the other is n-type; the source region 200 and the drain region 300 are of the same type, and a depletion layer is formed between the source region 200 or the drain region 300 and the substrate 100;

[0061] A halo injection region 400 is formed between the substrate 100 and a predetermined region, the predetermined region including a source region 200 and / or a drain region 300; the halo injection region 400 includes a first halo injection sub-region 410 for preventing direct channel penetration and a second halo injection sub-region 420 for regulating junction leakage current, wherein:

[0062] The first halo injection sub-region 410 covers the bottom and / or sides of the preset region; the depletion layer terminates within the first halo injection sub-region 410;

[0063] The second halo injection sub-region 420 covers the bottom and / or side of the first halo injection sub-region 410, and the diffusion layer formed by minority carrier diffusion on one side of the substrate 100 terminates in the second halo injection sub-region 420. The doping concentration of the second halo injection sub-region 420 is greater than the doping concentration of the first halo injection sub-region 410.

[0064] In the semiconductor device of this embodiment, a source region 200 and a drain region 300 are formed in a substrate 100, and a channel region is formed between the source region 200 and the drain region 300; a halo injection region 400 is formed in the substrate 100 and is located around the source region 200 and / or the drain region 300 to improve leakage current. Specifically, the first halo injection sub-region 410 covers the bottom and / or sides of a preset region, which includes a source region 200 and / or a drain region 300. The depletion layer terminates within the first halo injection sub-region 410 within the substrate 100, thus preventing direct channel penetration. Simultaneously, the second halo injection sub-region 420 covers the bottom and / or sides of the first halo injection sub-region 410. The diffusion layer formed by minority carrier diffusion on one side of the substrate 100 terminates within the second halo injection sub-region 420, and the doping concentration of the second halo injection sub-region 420 is greater than that of the first halo injection sub-region 410. The second halo injection sub-region 420 can reduce the concentration gradient between the first halo injection sub-region 410 it covers and the substrate 100, thereby reducing the likelihood of pn junction leakage and lowering the junction leakage current.

[0065] It should be noted that the semiconductor device provided in this embodiment can adjust the interface performance between the substrate 100 and the source region 200 and / or the drain region 300 by setting the halo injection region 400. Specifically, the first halo injection sub-region 410 can avoid channel punch-through, and the second halo injection sub-region 420 can reduce the junction leakage current, thereby achieving simultaneous optimization of the channel punch-through phenomenon and the pn junction leakage phenomenon.

[0066] It is worth noting that the halo injection region 400 formed by the first halo injection sub-region 410 and the second halo injection sub-region 420 is formed in the substrate 100. In other words, part of the structure of the substrate 100 is doped to form the halo injection region 400. There is no interface between the first halo injection sub-region 410 and the substrate 100, and it is completely replaced by the second halo injection sub-region 420.

[0067] To gain a clear understanding of the semiconductor structure provided in the embodiments of this disclosure, please refer to... Figure 2 The structure shown. Figure 2This diagram illustrates the leakage current path in a semiconductor device. The thick black lines with arrows represent punch-through leakage current, while the dashed lines with arrows represent pn junction leakage current. For more details, please refer to [link to relevant documentation]. Figure 1 The structure shown, taking NMOS (n-type metal oxide semiconductor) as an example, has a p-type substrate 100 and n-type drain region 300 and source region 200; since drain region 300 is connected to a high potential and substrate 100 is connected to a low potential (exemplary, such as...), Figure 1 The substrate 100 shown is connected to the ground (i.e., the substrate 100 is grounded), which results in a reverse bias current in the pn junction, increasing the device power consumption. Since the magnitude of the junction leakage current is usually controlled by minority carrier diffusion, reducing the minority carrier concentration gradient can reduce the junction leakage current. The second halo injection sub-region 420 is used to adjust the concentration gradient between the substrate 100 and the first halo injection sub-region 410.

[0068] It should be understood that MOS is an abbreviation for metal oxide semiconductor field-effect transistor, specifically divided into n-channel and p-channel types, i.e., NMOS and PMOS. The aforementioned PMOS stands for P-Metal-Oxide-Semiconductor, referring to a p-type metal-oxide-semiconductor, specifically an n-type substrate, p-channel MOS that carries current through the flow of holes. Furthermore, Figure 1 A halo injection region 400 is set only at the drain region 300. Of course, a halo injection region 400 can also be set between the source region 200 and the substrate 100, but the details will not be elaborated here.

[0069] Furthermore, "minority carriers" refers to a small number of charge carriers. In n-type semiconductors, holes are called minority carriers, and in p-type semiconductors, electrons are called minority carriers.

[0070] When specifically setting the halo injection region 400, the halo injection region 400 can be set only between the drain region 300 and the substrate 100, or it can be set only between the source region 200 and the substrate 100. Of course, the halo injection region 400 can also be set between both the source region 200 and the drain region 300 and the substrate 100.

[0071] Taking a halo-shaped injection region 400 between the drain region 300 and the substrate 100 as an example, since one of the drain region 300 and the substrate 100 is p-type and the other is n-type, and the source region 200 is of the same type as the drain region 300, a pn junction will be generated between the substrate 100 and the drain region 300, and between the substrate 100 and the source region 200. Specifically, in the pn junction, due to the diffusion motion of free electrons and the drift motion caused by the internal electric field, a very thin charge region is generated in the middle part of the pn junction (the interface between the p-region and the n-region), which is the depletion layer, also known as the space charge region. In other words, this depletion layer is formed by part of the substrate 100 and part of the drain region 300.

[0072] In one embodiment, the doping concentration of the first halo ring implantation sub-region 410 and the thickness of the first halo ring implantation sub-region 410 covering the preset region are used as structural parameters to prevent direct channel penetration.

[0073] The doping concentration of the second halo ring injection sub-region 420 and the thickness of the second halo ring injection sub-region 420 covering the first halo ring injection sub-region 410 are used as structural parameters to adjust the junction leakage current.

[0074] It should be noted that by adjusting the doping concentration of the first halo ring injection sub-region 410 and the thickness (along the current flow direction, also known as depth) covering the outside of the source region 200 or the drain region 300, direct channel punch-through can be avoided. At the same time, by adjusting the doping concentration of the second halo ring injection sub-region 420 and the thickness (along the current flow direction, also known as depth) covering the first halo ring injection sub-region 410, the magnitude of the junction leakage current can be reduced, thereby improving the pn junction leakage phenomenon.

[0075] In one embodiment, the doping concentration range of the first halo-ring implanted sub-region 410 is 1×e 11 ions / cm 2 ~1×e 13 ions / cm 2 .

[0076] It should be noted that by setting the doping concentration range of the first halo ring implantation sub-region 410 to the range mentioned above, the phenomenon of direct channel penetration can be avoided, thereby improving the effect.

[0077] In one embodiment, the doping concentration range of the second halo-ring implanted sub-region 420 is 1×e 13 ions / cm 2 ~1×e 16 ions / cm 2 .

[0078] It should be noted that by setting the doping concentration range of the second halo ring injection sub-region 420 to the range described above, minority carrier diffusion and junction leakage current can be reduced. When specifically setting the doping concentration of the second halo ring injection sub-region 420, it can be as high as possible, as long as it does not exceed saturation.

[0079] It is worth noting that, taking the example of a halo injection region 400 located between the drain region 300 and the substrate 100, the first halo injection sub-region 410 may only cover the bottom of the drain region 300, or the first halo injection sub-region 410 may only cover the side of the drain region 300, or the first halo injection sub-region 410 may simultaneously cover both the bottom and the side of the drain region 300. It should be understood that the "side" of the drain region 300 refers to the surface of the drain region 300 facing the source region 200.

[0080] Taking the first halo injection sub-region 410 covering the bottom of the leak area 300 as an example, the first halo injection sub-region 410 can cover at least a portion of the leak area 300. Similarly, when the first halo injection sub-region 410 covers the side of the leak area 300, the first halo injection sub-region 410 can cover at least a portion of the side of the leak area 300.

[0081] Furthermore, the second halo injection sub-region 420 may cover the bottom and / or sides of the first halo injection sub-region 410. Taking the second halo injection sub-region 420 covering the bottom of the first halo injection sub-region 410 as an example, the second halo injection sub-region 420 covers at least a portion of the first halo injection sub-region 410. Of course, when the second halo injection sub-region 420 covers the entire first halo injection sub-region 410, the concentration gradient between the first halo injection sub-region 410 and the substrate 100 can be better reduced to further optimize the pn junction leakage phenomenon.

[0082] For example, the positions of the first halo injection sub-region 410 and the second halo injection sub-region 420 can be as follows: Figure 3 and Figure 4 As shown. It should be understood that the positions of the first halo injection sub-region 410 and the second halo injection sub-region 420 can also be set in other forms, which can be set according to the requirements, but it is necessary to ensure that the second halo injection sub-region 420 covers the first halo injection sub-region 410. This coverage can be partial or complete coverage.

[0083] Please continue to refer to this. Figure 3 and Figure 4 In the structure shown, the thickness of the first halo injection sub-region 410 covering the preset area is shown as d1, and the thickness of the second halo injection sub-region 420 covering the first halo injection sub-region 410 is shown as d2. Taking the thickness d1 of the first halo injection sub-region 410 as an example, when the first halo injection sub-region 410 only covers the bottom of the drain area 300, the thickness d1 of the first halo injection sub-region 410 is as follows. Figure 3 As shown; when the first halo injection sub-region 410 covers the bottom and sides of the drain region 300, the thickness d1 of the first halo injection sub-region 410 is as follows. Figure 4 As shown. It should be understood that, Figure 4 The thickness of the bottom and sides of the first halo injection sub-region 410 covering the leak region 300 is d1.

[0084] It should be understood that the thickness of the first halo injection sub-region 410 and the thickness of the second halo injection sub-region 420 can be set with reference to the specific doping depth method in the semiconductor device formation method in the second aspect, and will not be elaborated here.

[0085] It is worth noting that there are electric field and potential changes in the depletion layer, and the potential change depends on the distribution of impurities in the semiconductor. The width of the depletion layer depends on the impurity concentration of the semiconductor. Based on this, the doping concentration of the first halo injection sub-region 410 can be adjusted so that the depletion layer partially terminates in the first halo injection sub-region 410 within the substrate 100.

[0086] When specifically setting the halo injection region 400, the edge of the depletion layer near the substrate 100 needs to terminate within the first halo injection sub-region 410. Specifically, the edge line of the depletion layer can be located within the boundary line of the first halo injection sub-region 410, or even, the edge line can be on the boundary line of the first halo injection sub-region 410 toward the second halo injection sub-region 420.

[0087] In one embodiment, on the side near the substrate 100, the edge of the depletion layer is spaced from the edge of the first halo injection sub-region 410, for example, as shown below. Figure 1 Region A in the diagram represents the depleted layer.

[0088] Specifically, by adjusting the doping concentration and doping depth of the first halo ring injection sub-region 410, it can be ensured that the depletion layer on the substrate 100 side is completely located within the first halo ring injection sub-region 410 (excluding the boundary line position).

[0089] It should be noted that this structural design facilitates the subsequent arrangement of a diffusion layer within the second halo injection sub-region 420, thereby preventing direct channel penetration and reducing junction leakage current.

[0090] It is worth noting that in the semiconductor device provided in this disclosure, the arrangement of the diffusion layer can be varied, specifically at least one of the following structures.

[0091] In one specific embodiment, the minority carrier diffusion layer on one side of the substrate 100, such as Figure 1 As shown in region B, it can be partially placed within the first halo injection sub-region 410 and partially placed within the second halo injection sub-region 420.

[0092] In another specific embodiment, the minority carrier diffusion layer on one side of the substrate 100 can be entirely placed within the second halo injection sub-region 420.

[0093] In one embodiment, please refer to... Figure 1 As shown in the diagram, the semiconductor device provided in this embodiment of the disclosure also includes a gate structure 500, which is formed on the surface of the substrate 100 and located on the channel region.

[0094] It should be noted that the gate structure 500 controls the generation of a channel in the channel region to achieve conduction between the source region 200 and the drain region 300.

[0095] In one embodiment, please refer to... Figure 1 The structure shown includes a gate structure 500 comprising a gate dielectric layer 510 formed on the surface of a substrate 100 and a gate conductive material layer 520 formed on the side of the gate dielectric layer 510 facing away from the substrate 100.

[0096] It should be noted that this structural configuration enables the gate structure 500 to effectively control the channel region. Specifically, the gate structure 500 is used to control whether current is formed between the source region 200 and the drain region 300.

[0097] In one embodiment, the gate dielectric layer 510 is made of silicon dioxide; the gate conductive material layer 520 is made of polysilicon.

[0098] It should be noted that the gate structure 500 formed by the above-mentioned material preparation has good performance. Of course, the gate dielectric layer 510 and the gate conductive material layer 520 can also be made of other materials. For example, the material of the gate dielectric layer 510 is a high dielectric constant material; the gate conductive material layer 520 can also be a metal.

[0099] In one embodiment, the substrate 100 is a silicon substrate 100. Of course, the substrate 100 can also be made of other materials, which will not be described in detail here.

[0100] It is worth noting that in the method of this embodiment, a well is formed on the substrate 1001. Taking the semiconductor device as an example of NMOS type, the well in the substrate 100 is p-type, that is, before forming the gate structure 500, the method further includes a step of well implantation to form a p-type well; the source region 200 and the drain region 300 are located in the formation region of the p-type well, and the gate structure 500 is formed on the surface of the p-type well.

[0101] Furthermore, it is worth noting that a field oxygen is also formed on the substrate 100, which isolates the active region 200. The p-type doped channel region is specifically composed of a p-type well located between the source region 200 and the drain region 300 and covered by the gate structure 500, and the surface of the channel region covered by the gate structure 500 is used to form the channel.

[0102] Secondly, embodiments of this disclosure provide a method for forming a semiconductor device, such as... Figure 5 A flowchart illustrating a method for forming a semiconductor device according to embodiments of this disclosure. Please refer to... Figures 1 to 4 refer to Figure 5 The method for forming a semiconductor device provided in this disclosure includes the following:

[0103] Step S502: Provide a substrate 100;

[0104] Step S504: A source region 200 and a drain region 300 are formed in the substrate 100, and a channel region is formed between the source region 200 and the drain region 300; one of the drain region 300 and the substrate 100 is p-type and the other is n-type, the source region 200 and the drain region 300 are of the same type, and a depletion layer is formed between the source region 200 or the drain region 300 and the substrate 100;

[0105] Step S506: Define the first doped region, perform the first ion implantation to form a first halo implantation sub-region 410 to prevent direct channel penetration. The first halo implantation sub-region 410 covers the bottom and / or sides of a preset region, which includes the source region 200 and / or the drain region 300. Terminate the depletion layer within the first halo implantation sub-region 410.

[0106] Step S508: Define a second doped region, perform a second ion implantation to form a second halo ring implantation sub-region 420 for adjusting the junction leakage current. The second halo ring implantation sub-region 420 covers the bottom and / or side of the first halo ring implantation sub-region 410. The diffusion layer formed by minority carrier diffusion on one side of the substrate 100 is terminated within the second halo ring implantation sub-region 420, and the doping concentration of the second halo ring implantation sub-region 420 is controlled to be greater than the doping concentration of the first halo ring implantation sub-region 410.

[0107] Step S5010: The first halo injection sub-region 410 and the second halo injection sub-region 420 form the halo injection region 400.

[0108] In the semiconductor device formed using the semiconductor formation method provided in this embodiment, a source region 200 and a drain region 300 are formed in a substrate 100, and a channel region is formed between the source region 200 and the drain region 300; a halo injection region 400 is formed in the substrate 100 and is located around the source region 200 and / or the drain region 300 to improve leakage current. Specifically, the first halo injection sub-region 410 covers the bottom and / or sides of a preset region, which includes a source region 200 and / or a drain region 300. The depletion layer terminates within the first halo injection sub-region 410 within the substrate 100, thus preventing direct channel penetration. Simultaneously, the second halo injection sub-region 420 covers the bottom and / or sides of the first halo injection sub-region 410. The diffusion layer formed by minority carrier diffusion on one side of the substrate 100 terminates within the second halo injection sub-region 420, and the doping concentration of the second halo injection sub-region 420 is greater than that of the first halo injection sub-region 410. The second halo injection sub-region 420 can reduce the concentration gradient between the first halo injection sub-region 410 it covers and the substrate 100, thereby reducing the likelihood of pn junction leakage and lowering the junction leakage current.

[0109] It should be noted that the semiconductor structure prepared by the formation method provided in this embodiment can adjust the interface performance between the substrate 100 and the source region 200 and / or the drain region 300 by setting the halo injection region 400. Specifically, the first halo injection sub-region 410 can avoid channel punch-through, and the second halo injection sub-region 420 can reduce the junction leakage current, thereby achieving simultaneous optimization of the channel punch-through phenomenon and the pn junction leakage phenomenon.

[0110] It should be understood that the semiconductor device provided in the first aspect of the present disclosure can also be prepared using this formation method, and the specific details will not be repeated here.

[0111] It is worth noting that in the semiconductor device formation method provided in this disclosure, the coverage position and doping depth of the first halo implantation sub-region 410 affect "how to define the first doped region", and the doping concentration of the first halo implantation sub-region 410 affects the implantation amount of "first ion implantation"; similarly, the coverage position and doping depth of the second halo implantation sub-region 420 affect "how to define the second doped region", and the doping concentration of the second halo implantation sub-region 420 affects the implantation amount of "second ion implantation".

[0112] Furthermore, a key aspect of the semiconductor device provided in this disclosure is to terminate the depletion layer in the first halo injection sub-region 410 and the minority carrier diffusion layer in the second halo injection sub-region 420. Therefore, determining the doping concentration and depth of the first halo injection sub-region 410 and the second halo injection sub-region 420 is an important step.

[0113] In one embodiment, before performing the first ion implantation in step S506, the method further includes:

[0114] Determine the doping concentration of the first halo ring implanted sub-region 410;

[0115] Determine the doping depth of the first halo ring implantation sub-region 410.

[0116] It should be noted that the doping depth and doping concentration of the first halo injection sub-region 410 are independent, so the doping depth and doping concentration can be considered to be non-orthogonal. One can be determined first and then the other.

[0117] It is worth noting that the lower limit of the doping concentration of the first halo ring implantation sub-region 410 can be used to determine whether channel direct punch-through occurs. Based on this, in one embodiment, the method for determining the doping concentration of the first halo ring implantation sub-region 410 includes:

[0118] A first comparison device group is formed, and each first comparison device in the first comparison device group is set to include a first halo injection sub-region 410. The doping concentration of the first halo injection sub-region 410 in each first comparison device is controlled to be different, and the doping depth of the first halo injection sub-region 410 in each first comparison device is the same.

[0119] Each of the first comparison devices in the first comparison device group is adjusted to the off state, and the source and drain voltages of the first comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping concentration of the first comparison device with the smallest current in the substrate 100 is taken as the doping concentration of the first halo ring injection sub-region 410.

[0120] It is worth noting that, when determining the first halo injection sub-region 410, each of the first comparison devices in the first comparison device group can be configured as follows: Figure 1 The structure shown on the left is the basic model. In other words, compared to existing devices, the first comparative device only adds a first halo injection sub-region 410.

[0121] For example, ten first comparison devices can be selected to form a first comparison device group, and the doping concentration of the first halo implantation sub-region 410 in the ten first comparison devices can be controlled to be different. It should be understood that the number of first comparison devices in the first comparison device group can be set according to requirements, which will not be elaborated here.

[0122] When comparing the first comparison devices, a certain number of devices can be selected sequentially for comparison, or 10 devices can be compared simultaneously to select the doping concentration that meets the requirements. Specifically, each of the first comparison devices in the first comparison device group is adjusted to the off state, and the source-drain voltage of the first comparison devices is controlled to be the same. Under the condition that the source-drain current is less than the threshold, the doping concentration of the first comparison device with the smallest current in the substrate 100 is taken as the doping concentration of the first halo ring implantation sub-region 410.

[0123] In one embodiment, a method for determining the doping depth of the first halo implantation sub-region 410 includes:

[0124] A second comparison device group is formed, and each second comparison device in the second comparison device group is set to include a first halo injection sub-region 410. The doping depth of the first halo injection sub-region 410 in each second comparison device is controlled to be different, and the doping concentration of the first halo injection sub-region 410 in each second comparison device is the same.

[0125] Each of the second comparison devices in the second comparison device group is adjusted to the off state, and the source and drain voltages of the second comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the second comparison device with the smallest current in the substrate 100 is taken as the doping depth of the first halo ring implantation sub-region 410.

[0126] It should be understood that the second comparison device group formed by determining the doping depth of the first halo implantation sub-region 410 is different from the first comparison device group when the doping concentration was determined. Specifically, the variable among the second comparison devices in the second comparison device group when the doping depth was determined is the doping depth. Furthermore, it should be noted that the terms "first" and "second" preceding the comparison device group have no sequential meaning and are only used for distinction.

[0127] It is worth noting that the doping depth of the first halo implantation sub-region 410 can be measured independently and can also be confirmed given a known doping concentration. To simplify the semiconductor device formation method provided in this disclosure, the doping depth of the first halo implantation sub-region 410 can be determined given a known doping concentration. It should be understood that once the doping concentration of the first halo implantation region 400 is determined, the doping concentration of each of the second comparison devices in the second comparison device group can be set to an optimal value to facilitate the selection of a doping depth range or an optimal doping depth.

[0128] It is worth noting that the doping depth of the first halo ring implantation sub-region 410 can also be confirmed by other methods. In one embodiment, the method for determining the doping depth of the first halo ring implantation sub-region 410 includes:

[0129] The estimated value is obtained by estimating the depletion layer depth on one side of the first halo injection sub-region 410 of the abrupt junction between the preset region and the substrate 100.

[0130] Based on the estimated value, the doping depth of the first halo ring injection sub-region 410 is adjusted so that the doping depth is greater than or equal to the estimated value.

[0131] In a specific embodiment, the depletion layer depth on one side of the first halo-ring implantation sub-region 410 of the abrupt junction between the preset region and the substrate 100 is estimated using the following formula:

[0132]

[0133] Where: d B_eq Indicates the depth of the depletion layer; X e_D X represents the electron concentration in the preset region. p_B n represents the hole concentration of substrate 100. i This indicates the intrinsic semiconductor carrier concentration.

[0134] It should be understood that the above is based on NMOS. For PMOS, simply interchange the subscripts D / B in the formula. The reverse-biased PN junction of PMOS is still between the substrate 100 and the drain region 300. However, for PMOS, the high potential is "source region 200" and the low potential is "drain region 300", with the substrate 100 connected to the "high potential". The intrinsic semiconductor carrier concentration is the equilibrium concentration of free electrons and free holes in the intrinsic semiconductor material, and the commonly used value is the concentration at 300K. The intrinsic carrier concentration is temperature-dependent; for semiconductors of the same material, the higher the temperature, the stronger the thermal excitation, and the higher the intrinsic carrier concentration. It is also related to the band gap; at the same temperature, the narrower the band gap, the easier it is for electrons or holes to transition from the valence band to the conduction band, resulting in a higher intrinsic carrier concentration.

[0135] It should be noted that by calculating d B_eq By determining the value of this value, we can determine the approximate depth of the depletion layer. Based on this, we can control the doping depth of the first halo implantation sub-region 410 to be greater than or equal to this value.

[0136] It is worth noting that when using the comparison device group to determine the doping depth of the first halo ring implantation sub-region 410, this method can also be selected to verify the doping depth obtained from the experimental comparison, which will not be elaborated further.

[0137] In one embodiment, prior to performing the second ion implantation, the method further includes:

[0138] Determine the doping concentration of the second halo-ring implanted sub-region 420;

[0139] Determine the doping depth of the second halo ring implantation sub-region 420.

[0140] It should be noted that the doping depth and doping concentration of the second halo injection sub-region 420 are independent, so the doping depth and doping concentration can be considered to be non-orthogonal. One can be determined first and then the other.

[0141] It should be understood that the doping concentration and doping depth of the second halo injection sub-region 420 can be established based on the already determined doping concentration and doping depth of the first halo injection sub-region 410.

[0142] In one embodiment, a method for determining the doping concentration of the second halo implantation sub-region 420 includes:

[0143] Adjust the ion concentration in the second doping region and determine the doping critical value when the ions in the second doping region are supersaturated.

[0144] Based on the doping critical value, the doping concentration of the second halo ring implanted sub-region 420 is controlled to be less than the doping critical value.

[0145] It should be noted that higher concentrations are more detrimental to minority carrier diffusion and more conducive to reducing junction leakage current. The second halo ring injection sub-region 420 should be doped as high as possible, as long as it is not oversaturated.

[0146] In one embodiment, a third comparison device group is formed, and each third comparison device in the third comparison device group includes a first halo injection sub-region 410 and a second halo injection sub-region 420. The doping depth of the second halo injection sub-region 420 in each third comparison device is controlled to be different, and the doping concentration of the second halo injection sub-region 420 in each third comparison device is the same.

[0147] Each of the third comparison devices in the third comparison device group is adjusted to the off state, and the source and drain voltages of the third comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the third comparison device with the smallest current in substrate 100 is taken as the doping depth of the second halo ring implantation sub-region 420.

[0148] It should be understood that when determining the doping depth of the second halo injection sub-region 420, the resulting third comparison device group differs from the first comparison device group when determining the doping concentration of the first halo injection sub-region 410 and the second comparison device group when determining the doping depth. This third comparison device simultaneously contains both the first halo injection sub-region 410 and the second halo injection sub-region 420, with the only variable being the doping depth of the second halo injection sub-region 420. Furthermore, it should be noted that the terms "first," "second," or "third" preceding the comparison device group or even the comparison device itself, have no sequential meaning and are used only for distinguishing purposes.

[0149] It is worth noting that the doping depth of the second halo injection sub-region 420 can be measured independently and can also be confirmed given that the doping concentration has been determined. To simplify the semiconductor device formation method provided in this disclosure, the doping depth of the second halo injection sub-region 420 can be tested given that the doping concentration of the second halo injection sub-region 420 has been determined. It should be understood that once the doping concentration of the second halo injection region 400 has been determined, the doping concentration of each of the third comparison devices in the third comparison device group can be set to an optimal value to facilitate the selection of the doping depth range or optimal doping depth of the second halo injection sub-region 420.

[0150] Of course, after the doping concentration and doping depth of the first halo injection sub-region 410 have been determined, the doping concentration and doping depth of the second halo injection sub-region 420 can also be determined to ensure that the doping concentration and doping depth of the first halo injection sub-region 410 in each of the third comparison devices in the third comparison device group are also at the optimal value, so as to facilitate the selection of the doping depth range or the optimal doping depth of the second halo injection sub-region 420.

[0151] For example, ten third comparison devices can be selected to form a third comparison device group, and the doping depth of the second halo implantation sub-region 420 in the ten third comparison devices can be controlled to be different. It should be understood that the number of comparison devices in the comparison device group can be set according to requirements, which will not be elaborated here.

[0152] When comparing the third comparison device, a certain number of devices can be selected sequentially for comparison, or 10 devices can be compared simultaneously to select the doping concentration that meets the requirements. Specifically, each of the third comparison devices in the third comparison device group is adjusted to the off state, and the source and drain voltages are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the comparison device with the smallest current in substrate 100 is taken as the doping depth of the second halo ring implantation sub-region 420.

[0153] It should be noted that the doping depth of the second halo implantation sub-region 420 can even be the width of the diffusion layer in the extreme diffusion state. The specific value can be set according to the requirements, which will not be elaborated here.

[0154] In one embodiment, the doping concentration range of the first halo-ring implanted sub-region 410 is 1×e 11 ions / cm 2 ~1×e 13 ions / cm 2 .

[0155] It should be noted that by setting the doping concentration range of the first halo ring implantation sub-region 410 to the range mentioned above, the phenomenon of direct channel penetration can be avoided, thereby improving the effect.

[0156] In one embodiment, the doping concentration range of the second halo-ring implanted sub-region 420 is 1×e 13 ions / cm 2 ~1×e 16 ions / cm 2 .

[0157] It should be noted that by setting the doping concentration range of the second halo ring injection sub-region 420 to the range described above, minority carrier diffusion and junction leakage current can be reduced. When specifically setting the doping concentration of the second halo ring injection sub-region 420, it can be as high as possible, as long as it does not exceed saturation.

[0158] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and exemplary embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0159] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for forming a semiconductor device, characterized in that, include: Provide a substrate; A source region and a drain region are formed within the substrate, and a channel region is formed between the source region and the drain region; one of the drain region and the substrate is p-type and the other is n-type, the source region and the drain region are of the same type, and a depletion layer is formed between the source region or the drain region and the substrate; Define a first doped region, perform a first ion implantation to form a first halo implantation sub-region to prevent direct channel penetration, the first halo implantation sub-region covering the bottom and / or sides of a preset region, the preset region including the source region and / or the drain region; terminate the depletion layer within the first halo implantation sub-region; Define a second doped region, perform a second ion implantation to form a second halo ring implantation sub-region for adjusting junction leakage current, the second halo ring implantation sub-region covers the bottom and / or side of the first halo ring implantation sub-region; terminate the diffusion layer formed by minority carrier diffusion on one side of the substrate within the second halo ring implantation sub-region, and control the doping concentration of the second halo ring implantation sub-region to be greater than the doping concentration of the first halo ring implantation sub-region; The first halo injection sub-region and the second halo injection sub-region form a halo injection region; Before performing the first ion implantation, the formation method further includes: determining the doping concentration and doping depth of the first halo implanted sub-region, wherein determining the doping depth of the first halo implanted sub-region includes: estimating the depletion layer depth of the abrupt junction between the preset region and the substrate on one side of the first halo implanted sub-region to obtain a preliminary value; adjusting the doping depth of the first halo implanted sub-region according to the preliminary value, such that the doping depth is greater than or equal to the preliminary value; wherein, when estimating the depletion layer depth of the abrupt junction between the preset region and the substrate on one side of the first halo implanted sub-region, the estimation is performed using the following formula: in: Indicates the depth of the depletion layer; Indicates the electron concentration in the preset region. Indicates the hole concentration in the substrate. This indicates the intrinsic semiconductor carrier concentration.

2. The method for forming a semiconductor device according to claim 1, characterized in that, The method for determining the doping concentration of the first halo implantation sub-region includes: A first comparison device group is formed, and each first comparison device in the first comparison device group is configured to include a first halo ring injection sub-region. The doping concentration of the first halo ring injection sub-region in each first comparison device is controlled to be different, and the doping depth of the first halo ring injection sub-region in each first comparison device is controlled to be the same. Each of the first comparison devices in the first comparison device group is adjusted to the off state, and the source and drain voltages of the first comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping concentration of the first comparison device with the smallest substrate current is taken as the doping concentration of the first halo ring injection sub-region.

3. The method for forming a semiconductor device according to claim 1, characterized in that, The method for determining the doping depth of the first halo implantation sub-region includes: A second comparison device group is formed, and each second comparison device in the second comparison device group is set to include a first halo ring implantation sub-region. The doping depth of the first halo ring implantation sub-region in each second comparison device is controlled to be different, and the doping concentration of the first halo ring implantation sub-region in each second comparison device is controlled to be the same. Each of the second comparison devices in the second comparison device group is adjusted to the off state, and the source and drain voltages of the second comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the second comparison device with the smallest substrate current is taken as the doping depth of the first halo ring implantation sub-region.

4. The method for forming a semiconductor device according to claim 1, characterized in that, Prior to performing the second ion implantation, the method further includes: Determine the doping concentration of the second halo implantation sub-region; Determine the doping depth of the second halo implantation sub-region.

5. The method for forming a semiconductor device according to claim 4, characterized in that, The method for determining the doping concentration of the second halo implanted sub-region includes: Adjust the ion concentration in the second doping region and determine the doping critical value when the ions in the second doping region are supersaturated. Based on the doping threshold, the doping concentration of the second halo injection sub-region is controlled to be less than the doping threshold.

6. The method for forming a semiconductor device according to claim 4 or 5, characterized in that, The method for determining the doping depth of the second halo implantation sub-region includes: A third comparison device group is formed, and each third comparison device in the third comparison device group is configured to include a first halo ring injection sub-region and a second halo ring injection sub-region. The doping depth of the second halo ring injection sub-region in each third comparison device is controlled to be different, and the doping concentration of the second halo ring injection sub-region in each third comparison device is controlled to be the same. Each of the third comparison devices in the third comparison device group is adjusted to the off state, and the source and drain voltages of the third comparison devices are controlled to be the same. Under the condition that the source and drain current is less than the threshold, the doping depth of the third comparison device with the smallest substrate current is taken as the doping depth of the second halo ring implantation sub-region.

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