A method for enhancing multi-layer thin film silicide by ion implantation

Abstract

The present invention proposes a method for ion implantation to enhance multi-layer thin film silicide. The method for ion implantation to enhance multi-layer thin film silicide is to penetrate a single layer or multiple layers of metal film that has been deposited on a semiconductor silicon substrate, bombard the single layer or multiple layers of metal film with argon ions, thereby forming a silicide layer on the surface of an ohmic contact region through the single layer or multiple layers of metal film. Specifically, it comprises: step 1, forming a semiconductor device region on a silicon wafer with a crystal orientation of 100; step 2, forming a single layer or multiple layers of metal film on the semiconductor silicon substrate of the semiconductor device region; step 3, bombarding the silicon wafer substrate with argon ions through the single layer or multiple layers of metal film, and forming a silicide layer on the surface of the ohmic contact region.

Description

Technical Field

[0001] The invention provides an ion implantation enhanced multi-layer thin film silicide method, belonging to the technical field of semiconductor device production. Background Art

[0002] The use of silicides is widespread in the field of semiconductor manufacturing. Silicides are silicon-metal alloys, typically composed of transition metals, including, for example, nickel (Ni), platinum (Pt), palladium (Pd), titanium (Ti), tungsten (W), tantalum (Ta), cobalt (Co), or alloys thereof. Silicides are typically used to provide low resistivity structures for contacting gate electrodes and source and drain electrodes in metal oxide semiconductor (MOS) devices. Transition metals have many desirable properties for silicides: they exhibit low resistivity, react with silicon at relatively low temperatures, and do not react with most dielectrics.

[0003] But the problem is that no one transition metal is right for every application. For example, using nickel silicide (NiSi) in the source and drain regions can be problematic because the nickel silicide will spike (i.e., continue to react beyond the point where it is needed) to form NiSi2 in the p+ active region, as well as intrude into the underlying gate spacer and gate electrode. Even variations in the metal concentration in the silicide can cause problems in devices. For example, while a nickel silicide containing, say, 10 atomic percent platinum (Ni.sub.0.90Pt.sub.0.10) is suitable for one device, such as a logic transistor, it may produce leakage problems in another device, such as a dynamic memory access transistor, as a result of a thermal annealing step used during the chip's back-end process processing. Conversely, while a silicide containing a higher concentration of platinum, such as 15 atomic percent platinum (Ni.sub.0.85Pt.sub.0.15), may be suitable for dynamic memory access transistors, it may produce some silicide corrosion problems in logic transistors.

[0004] The commonly used methods for forming semiconductor silicides are as follows:

[0005] 1. A single metal layer is deposited on silicon and then annealed to form a silicide layer, such as nickel (Ni), platinum (Pt), palladium (Pd), titanium (Ti), tungsten (W), tantalum (Ta), cobalt (Co), etc.

[0006] 2. A metal alloy layer is deposited on silicon and then annealed to form a silicide layer, such as nickel (Ni) / platinum (Pt) alloy, titanium (Ti) / nickel (Ni) alloy, etc.

[0007] The main disadvantage of the above-mentioned method is the peaking problem of silicide or silicide alloy, which has a great impact on the performance of high-end integrated circuits with small size and shallow junction.

[0008] 2. Poor stability and repeatability.

[0009] 3. Different silicide processes are required for different device applications. Summary of the invention

[0010] The present invention provides an ion implantation enhanced multilayer thin film silicide method, which can be used not only for low resistivity structures of gate electrodes and source and drain electrodes in contact metal oxide semiconductor (MOS) devices, but also for silicide layers and related processes used in various semiconductor devices, and is used to solve the problems of silicide or silicide alloy spikes, poor stability and repeatability, and poor compatibility of silicide process methods due to different silicide processes being required for different devices in the prior art:

[0011] The invention discloses an ion implantation enhanced multi-layer thin film silicide method, wherein the ion implantation enhanced multi-layer thin film silicide method is to penetrate a single layer or multiple layers of metal films deposited on a semiconductor silicon substrate, bombard the single layer or multiple layers of metal films with argon ions, thereby forming a silicide layer on the surface of an ohmic contact region through the single layer or multiple layers of metal films.

[0012] Further, the step of penetrating a single-layer or multi-layer metal film deposited on a semiconductor silicon substrate and bombarding the single-layer or multi-layer metal film with argon ions, thereby forming a silicide layer on the surface of the ohmic contact region through the single-layer or multi-layer metal film, comprises:

[0013] Step 1, forming a semiconductor device region on a silicon wafer with a crystal orientation of 100;

[0014] Step 2, forming a single-layer or multi-layer metal film on the semiconductor silicon substrate in the semiconductor device region;

[0015] Step 3: bombarding the silicon wafer substrate with argon ions through the single-layer or multi-layer metal film to form a silicide layer on the surface of the ohmic contact area.

[0016] Furthermore, the semiconductor device region includes a semiconductor silicon substrate, a silicon oxide insulating channel, a gate region, a source region and a drain region of a semiconductor field effect device.

[0017] Further, the process of forming a single layer on the semiconductor device region in step 2 includes:

[0018] In 2-9×10 -5A layer of metal film is deposited on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 100 Pa; wherein the thickness of the metal film is 30-60 nanometers (nm), and the metal film can be a nickel film of 30-60 nanometers (nm).

[0019] Further, the process of forming multiple layers on the semiconductor device region in step 2 includes:

[0020] Step 201, in 2-9×10 -5 Depositing a first metal film on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 100 Pa; wherein the thickness of the first metal film is 20 nanometers, and the first metal film can be a 20 nanometer nickel film;

[0021] Step 202, at 2-9×10 -5 A second metal film is deposited on the first metal film at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 0.1 Pa; wherein the thickness of the second metal film is 20 nanometers, and the second metal film can be a 20-nanometer platinum film.

[0022] Furthermore, the thickness of the single-layer or multi-layer metal film is 30-60 nanometers (nm).

[0023] Furthermore, in step 3, bombarding the silicon wafer substrate with argon ions through the single-layer or multi-layer metal film to form a silicide layer on the surface of the ohmic contact region includes:

[0024] Step 301, 1-4×10 15 cm -2 Argon ion bombardment is performed on a single-layer or multi-layer metal film having a thickness of 30-60 nanometers (nm) with an argon ion implantation dose of 100 keV and an argon ion implantation energy of 300-500 keV, thereby forming a silicide layer on an ohmic contact surface of a semiconductor silicon substrate by the argon ion bombardment;

[0025] Step 302 , performing nitrogen flow annealing treatment on the silicide layer at a temperature of 350° C. to 450° C. for 3 to 5 minutes to form a stably formed silicide layer.

[0026] Furthermore, the argon ion implantation dose is determined by:

[0027] When the metal film is a single-layer metal film, the dose and energy determination process of the argon ion implantation is as follows:

[0028] Determine the metal film thickness of the single-layer metal film, and determine the value of argon ion implantation dose and energy according to the argon ion implantation dose determination rule 1 based on the single-layer metal film thickness;

[0029] When the metal film is a multi-layer metal film, the process of determining the argon ion implantation dose and energy is as follows:

[0030] The thickness relationship of each metal film in the multi-layer metal film is determined, and based on the thickness relationship of each metal film, the value of argon ion implantation dose and energy is determined according to the second argon ion implantation dose determination rule.

[0031] Furthermore, the argon ion implantation dose determination rule 1 is as follows:

[0032] When the thickness of the single-layer metal film is 30nm≤h≤50nm, the 15 cm -2 The argon ion implantation dose was 1000 keV and the energy was 300 keV as the initial energy value for argon ion bombardment. During the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1×10 15 cm -2 Then, based on the initial energy value, the argon ion implantation dose is gradually increased to 4×10 15 cm -2 The optimal argon ion implantation dose is determined by the method; wherein the argon ion implantation dose adjustment amount per unit time corresponding to the stage of gradually reducing the argon ion implantation dose and the stage of increasing the argon ion implantation dose is obtained by the following formula:

[0033]

[0034]

[0035] Wherein, V1 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose; V2 represents the argon ion injection dose per unit time corresponding to the stage of increasing the argon ion injection dose; V0 represents the initial energy value; n represents the number of argon ion injection dose adjustments per unit time; h represents the thickness value of the metal film; ΔV1 represents the standard argon ion injection dose change per unit time corresponding to the stage of gradually reducing the argon ion injection dose, ΔV1=0.15×10 15 cm -2 ; ΔV2 represents the change in standard argon ion implantation dose per unit time corresponding to the stage of increasing argon ion implantation dose, ΔV2 = 0.3 × 10 15 cm -2 ;

[0036] When the metal film thickness of the single-layer metal film is in the range of 50nm < h ≤ 60nm, argon ion bombardment is carried out with an argon ion implantation dose of 4×10 15 cm -2 and an initial energy value of 300 KeV. During the argon ion bombardment, the optimal argon ion implantation dose is determined by gradually reducing the argon ion implantation dose to 1×10 15 cm -2 . Among them, the adjustment amount of the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose is obtained by the following formula:

[0037]

[0038] where V3 represents the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose when the metal film thickness of the single-layer metal film is in the range of 50nm < h ≤ 60nm; ΔV3 represents the standard change amount of the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose when the metal film thickness of the single-layer metal film is in the range of 50nm < h ≤ 60nm, and ΔV3 = 0.2×10 15 cm -2 .

[0039] Furthermore, the second rule for determining the argon ion implantation dose is as follows:

[0040] When the relationship between the thickness of the first metal thin film and the total thickness of the second to the Nth metal thin films in the multi-layer metal film satisfies h1 ≤ h2, argon ion bombardment is carried out with an argon ion implantation dose of 4×10 15 cm -2 and an argon ion implantation energy of 300 KeV as the initial value. During the argon ion bombardment, the optimal argon ion implantation dose is determined by gradually reducing the argon ion implantation dose to 1.8×10 15 cm -2 . Among them, the adjustment amount of the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose is obtained by the following formula:

[0041]

[0042] Wherein, V4 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thicknesses of the second metal film layer to the Nth metal film layer satisfies h1≤h2; h1 represents the thickness of the first metal film layer of the multilayer metal film; h2 represents the sum of the thicknesses of the second metal film layer to the Nth metal film layer; ΔV4 represents the standard argon ion injection dose change per unit time corresponding to the stage of reducing the argon ion injection dose when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thicknesses of the second metal film layer to the Nth metal film layer satisfies h1≤h2, ΔV4=0.35×10 15 cm -2 ;

[0043] When the relationship between the thickness of the first metal film and the sum of the thickness of the second metal film to the Nth metal film of the multilayer metal film satisfies h1>h2, 2×10 15 cm -2 The argon ion implantation dose and the argon ion implantation energy of 300KeV were used as the initial value for argon ion bombardment. During the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1×10 15 cm -2 Then, based on the initial energy value, the argon ion implantation dose is gradually increased to 4×10 15 cm -2 The optimal argon ion implantation dose is determined by the method; wherein the argon ion implantation dose adjustment amount per unit time corresponding to the stage of gradually reducing the argon ion implantation dose and the stage of increasing the argon ion implantation dose is obtained by the following formula:

[0044]

[0045]

[0046] Wherein, V5 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2; V6 represents the argon ion injection dose per unit time corresponding to the stage of increasing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2; V0 represents the initial energy value; n represents the number of times per unit time that the argon ion injection dose adjustment is experienced; h1 represents the thickness of the first metal film of the multilayer metal film; h2 represents the sum of the thicknesses of the second metal film to the Nth metal film; ΔV5 represents the standard argon ion injection dose change per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2, ΔV5=0.2×10 15 cm -2 ΔV6 represents the standard argon ion implantation dose change per unit time corresponding to the stage of increasing the argon ion implantation dose when the relationship between the thickness of the first metal film layer and the sum of the thickness of the second metal film layer to the Nth metal film layer satisfies h1>h2, ΔV6=0.3×10 15 cm -2 ; α and β represent adjustment coefficients, the value range of α is 0.48-0.56, and the value range of β is 0.77-0.90.

[0047] When the above method is used to obtain the optimal argon ion implantation dose value under the selected film conditions, such as film type, thickness, number of layers, etc., if the generated silicide thickness is not in line with the device performance requirements, the argon ion implantation energy can be gradually increased at a 50KeV energy interval under the initial condition of the optimal argon ion implantation dose value until the optimal silicide thickness is obtained. The argon ion implantation energy range does not exceed 500KeV.

[0048] Beneficial effects of the present invention:

[0049] The ion implantation enhanced multilayer thin film silicide method proposed in the present invention can effectively eliminate the peaking problem of silicide or silicide alloy, thereby greatly improving the stability and repeatability of silicide or silicide alloy, and at the same time, can greatly reduce the ohmic contact resistance, and the reduction range is as high as more than 70%; and the multilayer thin film silicide formed by the ion implantation enhanced multilayer thin film silicide method proposed in the present invention can significantly reduce the defect density of the device ohmic contact, and the maximum reduction range is more than 70%; at the same time, the ion implantation enhanced multilayer thin film silicide method adopted in the present invention can not only be used to reduce the ohmic contact resistance of silicon-based semiconductor devices and integrated circuits, but can also be promoted to reduce the ohmic contact resistance of compound semiconductor power devices and integrated circuits and improve the quality of devices, effectively improving the compatibility of the multilayer thin film silicide method. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The process of the method of the present invention is Figure 1 ;

[0051] Figure 2 The process of the method of the present invention is Figure 2 ;

[0052] Figure 3 It is a schematic diagram of the principle of the method of the present invention;

[0053] Figure 4 It is a schematic diagram of the principle of the method of the present invention;

[0054] (1, insulating channel; 2, source silicide ohmic contact region; 3, drain silicide ohmic contact region). DETAILED DESCRIPTION

[0055] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0056] The embodiment of the present invention provides an ion implantation enhanced multilayer thin film silicide method, which can be used not only for low resistivity structures of gate electrodes and source and drain electrodes in contact metal oxide semiconductor (MOS) devices, but also for silicide layers and related processes used in various semiconductor devices, and is used to solve the problems of silicide or silicide alloy peaking, poor stability and repeatability, and poor compatibility of silicide process methods due to different silicide processes being required for different devices in the prior art:

[0057] The invention discloses an ion implantation enhanced multi-layer thin film silicide method, wherein the ion implantation enhanced multi-layer thin film silicide method is to penetrate a single layer or multiple layers of metal films deposited on a semiconductor silicon substrate, bombard the single layer or multiple layers of metal films with argon ions, thereby forming a silicide layer on the surface of an ohmic contact region through the single layer or multiple layers of metal films.

[0058] Among them, Figure 1 As shown, the single-layer or multi-layer metal film deposited on the semiconductor silicon substrate is penetrated and argon ion bombarded on the single-layer or multi-layer metal film, thereby forming a silicide layer on the surface of the ohmic contact region through the single-layer or multi-layer metal film, including:

[0059] Step 1, forming a semiconductor device region on a silicon wafer with a crystal orientation of 100; wherein the semiconductor device region includes a semiconductor silicon substrate, a silicon oxide insulating channel, a gate region, a source region, and a drain region of a semiconductor field effect device;

[0060] Step 2, forming a single-layer or multi-layer metal film on the semiconductor silicon substrate in the semiconductor device region; wherein the thickness of the single-layer or multi-layer metal film is 30-60 nanometers (nm);

[0061] Step 3: bombarding the silicon wafer substrate with argon ions through the single-layer or multi-layer metal film to form a silicide layer on the surface of the ohmic contact area.

[0062] Wherein, the process of forming a single layer on the semiconductor device region in step 2 includes:

[0063] In 2-9×10 -5 A layer of metal film is deposited on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 100 Pa; wherein the thickness of the metal film is 30-60 nanometers (nm), and the metal film can be a nickel film of 30-60 nanometers (nm).

[0064] like Figure 2 As shown, the process of forming multiple layers on the semiconductor device region in step 2 includes:

[0065] Step 201, in 2-9×10 -5 Depositing a first metal film on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 100 Pa; wherein the thickness of the first metal film is 20 nanometers, and the first metal film can be a 20 nanometer nickel film;

[0066] Step 202, at 2-9×10 -5A second metal film is deposited on the first metal film at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 0.1 Pa; wherein the thickness of the second metal film is 20 nanometers, and the second metal film can be a 20-nanometer platinum film.

[0067] Among them, Figure 4 As shown, in step 3, argon ion bombardment is performed on the silicon wafer substrate through the single-layer or multi-layer metal film to form a silicide layer on the surface of the ohmic contact region, including:

[0068] Step 301, 1-4×10 15 cm -2 argon ion bombardment of a single or multi-layer metal film having a thickness of 30-60 nanometers (nm) with an ion implantation dose of 100 keV and an argon ion implantation energy of 300-500 keV, thereby forming a silicide layer on an ohmic contact surface of a semiconductor silicon substrate by the argon ion bombardment;

[0069] Step 302 , performing nitrogen flow annealing treatment on the silicide layer at a temperature of 350° C. to 450° C. for 3 to 5 minutes to form a stably formed silicide layer.

[0070] The working principle of the above technical solution is as follows: the method proposed in this embodiment makes the silicide layer of the semiconductor device have a thickness of 2–9×10 -5 Pa pressure at a deposition rate of 1 nanometer (nm) / second (s) to form the first layer of silicide film (such as a 20 nanometer nickel film), and then deposit the second layer of film (such as a 20 nanometer platinum film). In order to form a better ohmic contact, by 1-4×10 15 cm -2 A single or multi-layer metal film with a thickness of 30-60 nanometers (nm) is bombarded with argon ions at a dose of 300-500 keV, followed by an annealing process in a nitrogen flow at a temperature of 350°-450°C for 3 to 5 minutes to form a silicide layer on the surface of the ohmic contact area.

[0071] The technical process flow of the ion implantation enhanced multi-layer thin film silicide method includes the following main steps: according to the standard semiconductor process technology, including surface cleaning, insulating film growth, photolithography, ion etching, oxide deposition, chemical mechanical polishing and other processes, a semiconductor device region is formed on a silicon wafer with a crystal orientation of (100), such as Figure 3 As shown in Figure 1, its main structure is a semiconductor silicon substrate, a silicon oxide insulating channel, a gate region of a semiconductor field effect device, and a source and drain region. - 5Pa pressure at a deposition rate of 1 nanometer (nm) / second (s) to form a first layer of silicide (such as a 20 nanometer nickel film), and then deposit a second layer of silicide film (such as a 20 nanometer platinum film). In order to form a better ohmic contact, by 1-4×10 15 cm -2 The argon ion bombardment of a single or multi-layer metal film with a thickness of 30-60 nanometers (nm) is followed by an annealing process in a nitrogen flow at a temperature of 350°-450°C for 3 minutes to 5 minutes to form a silicide layer on the surface of the ohmic contact area. The energy and dose of argon ion implantation need to be determined experimentally according to the number of layers, type and thickness of the silicide film to obtain the best ohmic contact resistance and device reliability and stability.

[0072] In one embodiment of a single metal film, the silicide is first deposited on 9.10 -5 A nickel film with a thickness of 45 nm was formed at a pressure of 1 nm / s under a pressure of 10 Pa, and then argon ions were deposited at a rate of 4×10 15 cm -2 The nickel film is bombarded with a dose of 300 keV and an energy of 300 keV to form a nickel film on the surface of relevant areas (such as source area and drain area) of the silicon substrate. After formation, the semiconductor device manufactured according to the proposed method was subsequently studied in a nitrogen flow at a temperature of 350°C. The results are listed in the following Table 1.

[0073] Table 1: Comparison of Ohmic Contact Resistance Parameters of Semiconductor Devices Formed by Standard Process and Ohmic Contact Resistance Parameters of Semiconductor Devices Formed by Argon Ion Implantation Process

[0074]

[0075] The gate conductor may be made of conductive materials, including but not limited to metals, metal alloys, metal nitrides, metal silicides, and stacks and composites thereof. In one embodiment, the gate conductor may be any conductive material, including but not limited to: titanium (Ti), nickel (Ni), tungsten (W), platinum (Pt), copper (Cu), gold (Au), and alloys, or include at least one of the above materials. The gate conductor may also be made of a doping concentration ranging from about 1×10 18 cm -3 to about 1.0×102 21 cm -3The gate conductor may be composed of doped polysilicon and / or polysilicon-germanium alloy materials. The gate conductor may also be composed of a polysilicon material of a doped polysilicon / metal silicide stack material. The gate conductor may be formed using conventional deposition methods, including but not limited to self-aligned silicide methods, atomic layer deposition (ALD), CVD, PVD, evaporation, and sputtering. In one embodiment, the gate conductor may be a multilayer structure including more than one conductive material. The gate conductor may have a height ranging from about 20 nanometers (nm) to about 200 nanometers (nm).

[0076] The experimental research results show that the batch product rate of the silicon wafer structure manufactured in the best way has increased by 13.8%. Its technical effects are manifested in reduced contact resistance, improved reliability, and improved quality and product yield. In this embodiment, the gate dielectric can be an oxide, nitride or oxynitride of silicon. In another embodiment, the gate dielectric can be composed of a high-k dielectric material. The dielectric constant of the high-k dielectric material is higher than the dielectric constant of silicon dioxide (SiO2), which is about 4.0. High-k dielectric materials suitable for gate dielectrics may include but are not limited to hafnium oxide, hafnium silicate, titanium oxide, barium strontium titanate (BST) and lead zirconate titanate (PZT). The gate dielectric can be formed using any of a variety of deposition methods, including, for example, chemical vapor deposition (CVD) and physical vapor deposition (PVD). In one embodiment, the thickness of the gate dielectric may be between about 1 nanometer (nm) and about 20 nanometers (nm).

[0077] The effects of the above technical scheme are as follows: the ion implantation enhanced multilayer thin film silicide method proposed in this embodiment can effectively eliminate the peaking problem of silicide or silicide alloy, thereby greatly improving the stability and repeatability of silicide or silicide alloy, and at the same time, can greatly reduce the ohmic contact resistance, and the reduction range is as high as more than 70%; and the multilayer thin film silicide formed by the ion implantation enhanced multilayer thin film silicide method proposed in this embodiment can significantly reduce the defect density of the device ohmic contact, and the maximum reduction range is more than 70%; at the same time, the ion implantation enhanced multilayer thin film silicide method adopted in the embodiment can not only be used to reduce the ohmic contact resistance of silicon-based semiconductor devices and integrated circuits, but can also be promoted to reduce the ohmic contact resistance of compound semiconductor power devices and integrated circuits and improve the quality of devices, effectively improving the compatibility of the multilayer thin film silicide method.

[0078] In one embodiment of the present invention, the argon ion implantation dose is determined by:

[0079] When the metal film is a single-layer metal film, the dose and energy determination process of the argon ion implantation is as follows:

[0080] Determine the metal film thickness of the single-layer metal film, and determine the value of argon ion implantation dose and energy according to the argon ion implantation dose determination rule 1 based on the single-layer metal film thickness;

[0081] When the metal film is a multi-layer metal film, the process of determining the argon ion implantation dose and energy is as follows:

[0082] The thickness relationship of each metal film in the multi-layer metal film is determined, and based on the thickness relationship of each metal film, the value of argon ion implantation dose and energy is determined according to the second argon ion implantation dose determination rule.

[0083] The first rule for determining the argon ion implantation dose is as follows:

[0084] When the thickness of the single-layer metal film is 30nm≤h≤50nm, the 15 cm -2 The argon ion implantation dose was 1000 keV and the energy was 300 keV as the initial energy value for argon ion bombardment. During the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1×10 15 cm -2 Then, based on the initial energy value, the argon ion implantation dose is gradually increased to 4×10 15 cm -2 The optimal argon ion implantation dose is determined by the method; wherein the argon ion implantation dose adjustment amount per unit time corresponding to the stage of gradually reducing the argon ion implantation dose and the stage of increasing the argon ion implantation dose is obtained by the following formula:

[0085]

[0086]

[0087] Wherein, V1 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose; V2 represents the argon ion injection dose per unit time corresponding to the stage of increasing the argon ion injection dose; V0 represents the initial energy value; n represents the number of argon ion injection dose adjustments per unit time; h represents the thickness value of the metal film; ΔV1 represents the standard argon ion injection dose change per unit time corresponding to the stage of gradually reducing the argon ion injection dose, ΔV1=0.15×10 15 cm -2 ; ΔV2 represents the change in standard argon ion implantation dose per unit time corresponding to the stage of increasing argon ion implantation dose, ΔV2 = 0.3 × 10 15 cm -2 ; The value range of the unit time is 20s-55s, preferably 38s;

[0088] When the metal film thickness of the single-layer metal film is 50 nm < h ≤ 60 nm, argon ion bombardment is carried out with an argon ion implantation dose of 4×10 15 cm -2 and an initial energy value of 300 keV. During the argon ion bombardment, the optimal argon ion implantation dose is determined by gradually reducing the argon ion implantation dose to 1×10 15 cm -2 . Among them, the adjustment amount of the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose is obtained by the following formula:

[0089]

[0090] where V3 represents the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose when the metal film thickness of the single-layer metal film is 50 nm < h ≤ 60 nm; ΔV3 represents the standard argon ion implantation dose change amount per unit time corresponding to the stage of reducing the argon ion implantation dose when the metal film thickness of the single-layer metal film is 50 nm < h ≤ 60 nm, and ΔV3 = 0.2×10 15 cm -2 .

[0091] The second rule for determining the argon ion implantation dose is as follows:

[0092] When the relationship between the thickness of the first metal thin film of the multi-layer metal film and the total thickness of the second to the Nth metal thin films satisfies h1 ≤ h2, argon ion bombardment is carried out with an argon ion implantation dose of 4×10 15 cm -2 and an initial energy value of 300 keV. During the argon ion bombardment, the optimal argon ion implantation dose is determined by gradually reducing the argon ion implantation dose to 1.8×10 15 cm -2 . Among them, the adjustment amount of the argon ion implantation dose per unit time corresponding to the stage of reducing the argon ion implantation dose is obtained by the following formula:

[0093]

[0094] Wherein, V4 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thicknesses of the second metal film layer to the Nth metal film layer satisfies h1≤h2; h1 represents the thickness of the first metal film layer of the multilayer metal film; h2 represents the sum of the thicknesses of the second metal film layer to the Nth metal film layer; ΔV4 represents the standard argon ion injection dose change per unit time corresponding to the stage of reducing the argon ion injection dose when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thicknesses of the second metal film layer to the Nth metal film layer satisfies h1≤h2, ΔV4=0.35×10 15 cm -2 ;

[0095] When the relationship between the thickness of the first metal film and the sum of the thickness of the second metal film to the Nth metal film of the multilayer metal film satisfies h1>h2, 2×10 15 cm -2 The argon ion implantation dose was 1000 keV and the energy was 300 keV as the initial energy value for argon ion bombardment. During the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1×10 15 cm -2 Then, based on the initial energy value, the argon ion implantation dose is gradually increased to 4×10 15 cm -2 The optimal argon ion implantation dose is determined by the method; wherein the argon ion implantation dose adjustment amount per unit time corresponding to the stage of gradually reducing the argon ion implantation dose and the stage of increasing the argon ion implantation dose is obtained by the following formula:

[0096]

[0097]

[0098] Wherein, V5 represents the argon ion injection dose per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2; V6 represents the argon ion injection dose per unit time corresponding to the stage of increasing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2; V0 represents the initial energy value; n represents the number of times per unit time that the argon ion injection dose adjustment is experienced; h1 represents the thickness of the first metal film of the multilayer metal film; h2 represents the sum of the thicknesses of the second metal film to the Nth metal film; ΔV5 represents the standard argon ion injection dose change per unit time corresponding to the stage of gradually reducing the argon ion injection dose when the relationship between the thickness of the first metal film of the multilayer metal film and the sum of the thicknesses of the second metal film to the Nth metal film satisfies h1>h2, ΔV5=0.2×10 15 cm -2 ΔV6 represents the standard argon ion implantation dose change per unit time corresponding to the stage of increasing the argon ion implantation dose when the relationship between the thickness of the first metal film layer and the sum of the thickness of the second metal film layer to the Nth metal film layer satisfies h1>h2, ΔV6=0.3×10 15 cm -2 ; α and β represent adjustment coefficients, the value range of α is 0.48-0.56, and the value range of β is 0.77-0.90.

[0099] When the above method is used to obtain the optimal argon ion implantation dose value under the selected film conditions, such as film type, thickness, number of layers, etc., if the generated silicide thickness is not in line with the device performance requirements, the argon ion implantation energy can be gradually increased at a 50KeV energy interval under the initial condition of the optimal argon ion implantation dose value until the optimal silicide thickness is obtained. The argon ion implantation energy range does not exceed 500KeV.

[0100] The effect of the above technical solution is: the acquisition efficiency of the optimal argon ion implantation dose can be effectively improved by the above method. At the same time, the adjustment amount of the argon ion implantation dose per unit time obtained by the above formula can effectively improve the acquisition efficiency of the optimal argon ion implantation dose, and can maximally limit the variation of the argon ion implantation dose per unit time, so as to prevent the variation adjustment from being too large, resulting in the inability to accurately and quickly obtain the optimal argon ion implantation dose, or the variation adjustment from being too small, resulting in the determination time of the optimal argon ion implantation dose being too long, thereby reducing the accuracy and efficiency of obtaining the optimal argon ion implantation dose. At the same time, the above-mentioned acquisition adjustment method of the optimal argon ion implantation dose and the optimal argon ion implantation dose formula can not only be applied to reduce the ohmic contact resistance of silicon-based semiconductor devices and integrated circuits, but also can be applied to experiments to reduce the ohmic contact resistance of compound semiconductor power devices and integrated circuits and improve the quality of devices, effectively improving the application compatibility and extensiveness of the above-mentioned acquisition adjustment method of the optimal argon ion implantation dose.

[0101] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for enhancing multi-layer thin film silicide by ion implantation, characterized in that: The ion implantation enhanced multi-layer thin film silicide method is to penetrate a single layer or multiple layers of metal films deposited on a semiconductor silicon substrate, bombard the single layer or multiple layers of metal films with argon ions, thereby forming a silicide layer on the surface of an ohmic contact region through the single layer or multiple layers of metal films, comprising: Step 1, forming a semiconductor device region on a silicon wafer; Step 2, forming a single-layer or multi-layer metal film on the semiconductor silicon substrate in the semiconductor device region; Step 3, bombarding the semiconductor silicon substrate with argon ions through the single-layer or multi-layer metal film to form a silicide layer on the surface of the ohmic contact region, comprising: Step 301, 1-4×10 15 cm -2 Argon ion bombardment is performed on a single-layer or multi-layer metal film having a thickness of 30-60 nanometers (nm) with an argon ion implantation dose of 100 keV and an argon ion implantation energy of 300-500 keV, thereby forming a silicide layer on an ohmic contact surface of a semiconductor silicon substrate through the argon ion bombardment; Step 302, performing nitrogen flow annealing treatment on the silicide layer at a temperature of 350°C-450°C for 3-5 minutes to form a stably formed silicide layer; Wherein, the argon ion implantation dose is determined by the following method: When the metal film is a single-layer metal film, the dose and energy determination process of the argon ion implantation is as follows: Determine the metal film thickness of the single-layer metal film, and determine the values of the argon ion implantation dose and energy according to the first rule for determining the argon ion implantation dose based on the single-layer metal film thickness; the first rule for determining the argon ion implantation dose is as follows: when the metal film thickness of the single-layer metal film is in the range of 30nm ≤ h ≤ 50nm, use an argon ion implantation dose of 1.8×10 15 cm -2 and an energy of 300KeV as the initial values for argon ion bombardment, and during the argon ion bombardment process, gradually reduce the argon ion implantation dose to 1×10 15 cm -2 , and then gradually increase the argon ion implantation dose to 4×10 15 cm -2 based on the initial energy value to determine the optimal argon ion implantation dose; when the metal film thickness of the single-layer metal film is in the range of 50nm < h ≤ 60nm, use an argon ion implantation dose of 4×10 15 cm -2 and an energy of 300KeV as the initial values for argon ion bombardment, and during the argon ion bombardment process, gradually reduce the argon ion implantation dose to 1×10 15 cm -2 to determine the optimal argon ion implantation dose; When the metal film is a multi-layer metal film, the process of determining the argon ion implantation dose and energy is as follows: Determine the thickness relationship of each metal film in the multilayer metal film, and determine the value of argon ion implantation dose and energy according to the thickness relationship of each metal film according to the second argon ion implantation dose determination rule; the second argon ion implantation dose determination rule is as follows: when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thicknesses of the second metal film layer to the Nth metal film layer satisfies h 1≤ h 2, with 4×10 15 cm -2 The argon ion implantation dose and energy of 300KeV were used as the initial value for argon ion bombardment, and during the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1.8×10 15 cm -2 The optimal argon ion implantation dose is determined by the method; when the relationship between the thickness of the first metal film layer of the multilayer metal film and the sum of the thickness of the second metal film layer to the Nth metal film layer satisfies h 1> h 2, 2×10 15 cm -2 The argon ion implantation dose and energy of 300KeV were used as the initial value for argon ion bombardment, and during the argon ion bombardment, the argon ion implantation dose was gradually reduced to 1×10 15 cm -2 Then, based on the initial energy value, the argon ion implantation dose was gradually increased to 4×10 15 cm -2 The optimal argon ion implantation dose is determined by 2. The method for ion implantation enhanced multi-layer thin film silicide according to claim 1, characterized in that: The crystal orientation of the silicon wafer is (100).

3. The method for ion implantation enhanced multi-layer thin film silicide according to claim 1, characterized in that: The semiconductor device region includes a semiconductor silicon substrate, a silicon oxide insulating channel, a gate region, a source region and a drain region of a semiconductor field effect device.

4. The method for ion implantation enhanced multi-layer thin film silicide according to claim 1, characterized in that: The process of forming a single layer on the semiconductor device region in step 2 includes: In 2-9×10 -5 A metal film is deposited on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 0.1 Pa.

5. The method for ion implantation enhanced multi-layer thin film silicide according to claim 1, characterized in that: The process of forming a multilayer on the semiconductor device region in step 2 includes: Step 201, in 2-9×10 -5 Depositing a first metal film on the semiconductor silicon substrate at a deposition rate of 1 nanometer (nm) / second (s) under a pressure of 100 Pa; Step 202, at 2-9×10 -5 A second metal film is deposited on the first metal film at a pressure of 0.1 Pa and a deposition rate of 1 nanometer (nm) / second (s).

6. The method for ion implantation enhanced multi-layer thin film silicide according to claim 1, 4 or 5, characterized in that: The thickness of the single-layer or multi-layer metal film is 30-60 nanometers (nm).

7. The method for enhancing multi-layer thin film silicide by ion implantation according to claim 1, characterized in that: The rule for determining the argon ion implantation energy is as follows: when the thickness of the generated silicide is not in line with the device performance requirements, the argon ion implantation energy is gradually increased at 50 KeV energy intervals under the initial condition of using the optimal argon ion implantation dose value until the optimal silicide thickness is obtained.

Images