TW478104B - Nitrogen oxide in-situ steam generation process - Google Patents

Abstract

An ultra-thin nitrogen oxide layer in-situ steam generation process comprises: mounting a silicon substrate in a reaction chamber; introducing N2O and H2 gases into the reaction chamber which is at a pressure lower than 10 Torr; heating the surface of the silicon substrate to a predetermined temperature of about 800 to 1100 DEG C in order to form a silicon nitride layer on the heated surface of the silicon substrate, in which the silicon nitride layer comprises about 1 to 5 atomic % of nitrogen atoms.

Description

478104 V. Description of the invention (1) 5-1 Field of the invention: The present invention relates to a method for forming a dielectric layer for a semiconductor device; in particular, it relates to a method for forming a nitrogen-containing silicon dioxide dielectric layer. 5-2 Background of the Invention: The trend of integrated circuits is toward higher operating performance, faster speeds, and lower prices. Correspondingly, the size of component sizes has gradually decreased with the advancement of integrated circuit technology. The development of this trend necessitates the use of ultra-thin dielectric layers for the fabrication of semiconductor devices such as metal-oxide-semiconductor half-effect transistors. Broken electricity is here. The layer weight is a medium, and the dielectric phase is applied to the pole. The gate voltage is extremely thin. The source layer is a thin layer, and an appropriate thin crystal electrode is more electrically drawn from a source, and is used in the efficiency. . The coupling field is doped with a polar shape connected to a semi-high-polarity electrical system, an oxygen-drain channel, and a gate electrode. The polarized super-speed body source electric power source fast crystal is more conductive and effective. More type. After a short time in the field, the small element and the material are more oxygen-rich. The bottom layer can pass through the photoresist on the upper silicon electrode and the bottom layer is shorter than the bottom layer. The thickness should be less than 100 angstroms or even 0.1. The 3 / zm process uses an ultra-thin dielectric layer of 15 angstroms, which is usually formed of high-quality silicon dioxide. This ultra-thin silicon dioxide layer is used for metal-oxygen half field

Page 4 478104 V. Description of the invention (2) The gate dielectric layer of an effect transistor is generally called a gate oxide layer. For the same gate oxide material, when its thickness is reduced from several hundred angstroms to several tens angstroms, some quantum effects such as side penetration (boron penetration) and hot carrier effects will occur. For an ultra-thin gate oxide layer, boron atoms can pass through the gate oxide layer from the doped polycrystalline silicon gate and enter the substrate below it, causing a serious gate-starting voltage shift problem. The hot electrons generated near the anode due to the hot carrier effect are also very easy to shoot into the ultra-thin gate oxide layer, and destroy the gate oxide layer and / or the Si-SiO junction. Factors such as poor junction structure, south defect, poor thickness control, and impurity diffusion to the gate oxide layer also adversely affect the ultra-thin gate oxide layer. These factors also seriously affect the operational performance of semiconductor devices. Incorporation of nitrogen atoms into the ultra-thin gate oxide layer has been shown to inhibit boron penetration and improve the S i -S i 0 妁 junction structure. The lum oxide process is made possible by the quality control of the ultra-thin oxide layer (approximately 12 to 20 angstroms) doped with nitrogen and its manufacturing method. Traditional in-situ steam generation (ISSG) oxides have excellent oxide quality. However, in the traditional accompanying steam generation process, at a temperature of about 900 ° C, an ultra-thin gate oxide layer with a thickness of about 15 Angstroms is manufactured, and the reaction time only takes 丨 0 seconds. The traditional I S S G process is extremely fast, making it extremely difficult to control the thickness of the formed ultra-thin free oxygen layer (less than 15 angstroms). In addition, the gate oxide layer manufactured by the traditional I S S G process is a pure gate oxide layer, and it is impossible to inhibit the penetration of hot stones and the injection of hot electrons into the gate oxide layer. Therefore, the traditional 丨 SSG process benefits method is applicable to 0 · 1 3 um process or even a newer generation process, such as ..., 478104 V. Description of the invention (3), ultra-thin gate oxide layer with a thickness of about 12 to 20 angstroms . Accordingly, there is an urgent need to provide a nitrous oxide along with steam generation process (N 2〇in-situ steam generation process) (N20-ISSG process), which can provide ultra-thin for 0_ 1 3 um process, and even newer generation processes Gate dielectric layer. 5-3 Purpose and summary of the invention: The main purpose of the present invention is to provide a nitric oxide-qi ^-lice accompanied by the N20-ISSG process to form ultra-thin gasification II, dairy ISS ( ;, Ultra-thin nitrided gate oxide). This idle oxidation layer uses N 2 0 and rhenium as reactive gases to form an ultra-thin nitrogen on a silicon substrate. This ultra-thin nitrided gate oxide layer Contains the region of the gate oxide layer and its interface with the broken substrate, so that the hot electrons generated by the atomic surface effect can be suppressed from entering the gate oxide layer. Tooth penetration and hot planting Another object of the present invention is Provided is a process of nitric oxide and oxidation, which uses Νζ0 and Η as reaction gases ^ to form an ultra-thin nitride gate oxide layer along with steam production. This NA-ISSG ^ is performed on a silicon substrate, and its The reaction speed is higher than the traditional ISSG. ^ It can be at a higher temperature, so the space of this N20-ISSG process is wider than the traditional ISSG process. ^% Slower. Processwindow). See the system

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478104 V. Description of the invention (4) According to the above-mentioned purpose, the present invention provides a process for generating nitrous oxide with steam (n2o-issg) to form an ultra-thin nitride gate oxide layer on the silicon substrate. For gate dielectric layer. The N 20- I SSG process includes placing a silicon substrate in a reaction chamber, and sending a mixed gas containing N 20 and ΗA into the reaction chamber. After that, the surface of the Shixi substrate is heated to a predetermined temperature to form a silicon nitride layer on the heated surface of the silicon substrate. This nitrided silicon dioxide layer contains nitrogen atoms in the surface area and the interface area with the silicon substrate. These nitrogen atoms can suppress the heat generated by the penetration of boron from the doped polycrystalline silicon gate and the thermal carrier effect. Electrons are injected into this nitride gate oxide layer. The purpose and many advantages of the present invention will become clearer through the detailed description of the following specific embodiments and with reference to the accompanying drawings. 5-4 Detailed description of specific embodiments: The first figure is a schematic cross-sectional view of a rapid thermal process chamber 1 0 0 in which one of the rapid heating process chambers of the present invention is implemented. A single wafer, such as a silicon substrate 100, is placed on a carrier plate in the rapid heating process reaction chamber 100. The reaction gas N 20 and Η # are sent to the rapid heating process reaction chamber 100 through a gas inlet 10 2. The residual gas system is withdrawn through a gas outlet 103.

478104

V. Description of the invention (5) With the implementation of the specific implementation (IM 20-I SSG process), it will have a clean surface;] :. In step 0, the material is added to the reaction chamber 10, and in step 20, the rapid heating system with a housing force of less than 10 Torr is fed into the rapid wide system. Within 20 and 0. This mixed gas mainly contains the… chamber :! Rate:…%. In step 202, the Shixi substrate is heated to a temperature of about 80. ~ 1 1. t: in the step 2 „Surface 1: Induced by heating the surface as shown in the following reaction formula = 3, the bottom: the generation of oxygen atoms (0) and nitric oxide on the surface of“ sheng 1. ”Then, as shown in the third figure, _ΐί: : Substrate 1 〇Xynitride) (Si〇2, Nx) 1 〇4 is formed on the surface of the stone xixi layer (), which can be used as the gate 〇1 after heating ... by -nitrogen oxide ". &Quot; From the official: Oxygenation: Formed in an n2O-ISSG process at about 1050 °° C for 20 seconds or longer. The reaction time required by the household is about H2 + M — H20 + NCT + 0 * + 0H * + other species (n. The traditional .ISSG process forms an ultra-thin gate oxide layer with a thickness of about 5 Angstroms, and the reaction time is only 10 seconds. If an ultra-thin gate dielectric layer is to be formed (^ 15 Angstroms), the NgO-ISSG process of the present invention has a slower response speed than the traditional ISSG process. Therefore, it is necessary to form an ultra-thin gate electrode. Dielectric layer 478104 V. Description of the invention (6) The N20-ISSG process of the present invention can provide better thickness control than the traditional ISSG process. As shown in the third figure, it is formed by the N20-ISSG process of the present invention. The silicon oxynitride layer 104 has a nitrogen content of about 1 to 5 atomic%. Therefore, the silicon oxynitride layer 104 has a nitrogen content of about 1 to 5 in the surface area and the interface area with the silicon substrate 1 0 1. at 〇mic%. These nitrogen atoms can inhibit boron penetration from the doped polycrystalline silicon gate and hot electrons generated by the hot carrier effect from entering the silicon oxynitride layer used as the gate dielectric layer 104. The 1 ~ 5 atomic% nitrogen content contained in the silicon oxynitride layer 104 can also increase the dielectric constant of the silicon oxynitride layer 104. And to improve the operation performance of the gold-oxygen half field effect transistor using the silicon oxynitride layer 104 as its gate dielectric layer. In another preferred embodiment of the present invention, Prior to the steam generation process (N 20- I SSG pr 〇cess), the nitridation reaction was performed on the surface of the silicon substrate 1 0 1. 〇 · 一 私 / 土 面面 说 丨 么 ”* HU Master of An 筮 TO Garden in Nai Shao. Lizhou • Step 4 478104 V. Description of the Invention (7) Use a temperature of about 5 0 ~ 80 0 ° C and a pressure of about 1 ~ 3 Torr. Reaction gas. In step 4 2, the system containing N 20 and krypton mixed gas is sent into the reaction chamber 1 of the rapid heating process with a pressure lower than 10 Torr 478104. 5. Description of the invention (8) According to the above, The nitrous oxide of the present invention along with the steam generation process (N20-ISSG process) can provide an ultra-thin gate dielectric layer ($ 15 Angstrom) with good thickness control, such as an ultra-thin silicon oxynitride layer. This ultra-thin gate The dielectric layer can effectively suppress quantum effects, such as boron penetration and hot carrier effects. Nitrous oxide, one of the present inventions, is produced with steam. Process may also be controlled so that higher temperatures (greater than 1 0 0 0 ° C) feasible. Thus, the present invention is a steam generator along with nitrous oxide processes than the traditional process I SSG process having a wider space.

478104 The diagram is briefly explained. The first diagram is not intended to implement the cross-section of the reaction chamber of a rapid heating process of the present invention. The second diagram is a flowchart of a preferred embodiment of the present invention. A schematic cross-sectional view of a silicon nitride dioxide structure manufactured by the process; the fourth diagram is a flowchart of another preferred embodiment of the present invention; and

The fifth graph is a graph showing the relationship between the nitrogen content of the silicon oxynitride layer and the depth of the Shixi substrate according to the process of the fourth graph. Main symbols: 10 0 Rapid heating process reaction chamber 101 Silicon substrate 10 2 Gas inlet 10 3 Gas outlet 10 4 Silicon oxynitride layer

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Claims (1)

478104 VI. Application for Patent Scope 1. A process for generating nitride oxide accompanying (i η-situ) vapor, which at least includes: heating a surface of a silicon substrate to a predetermined temperature, and exposing the silicon substrate to heat The surface is in a mixed gas, the mixed gas system is sent to a reaction chamber, and contains N 20 and Η 2, thereby forming a silicon dioxide layer on the heated surface of the silicon substrate, the The silicon dioxide layer contains nitrogen. 2. If the process of item 1 of the scope of patent application is applied, the above-mentioned mixed gas mainly contains N 2O. 3. If the process of item 2 of the scope of patent application is applied, the above mixed gas package contains Η 2 with a gas ratio of less than 1%. 4. For the process of claim 1 in the scope of patent application, wherein the above mixed gas system is sent to the reaction chamber with a pressure lower than 10 Torr. 5. For the process of applying for the first item of the patent scope, wherein the predetermined temperature mentioned above is about 800 ~ 1100 ° C. 6. If the process of item 1 of the patent scope is applied, the thickness of the above silicon dioxide layer is less than 15 angstroms. 7. For the process of claim 1 in the scope of patent application, wherein the nitrogen content of the above silicon dioxide layer is about 1 ~ 5 atomic%. 478104 6. Scope of patent application 8. If the process of item 1 of the scope of patent application is applied, the nitrogen content on the surface of the above silicon dioxide layer is about 1 ~ 5 atomic%. 9. For the process of applying for the item 1 in the scope of patent application, wherein the nitrogen content at the interface between the above silicon dioxide layer and the Shixi substrate is about 1 ~ 5 a t 0 m i c%. 10. The process of item 1 in the scope of patent application further includes performing a nitriding reaction on the surface of the substrate before performing the accompanying steam generation process. 11. The process of item 10 in the scope of patent application, wherein the above-mentioned nitriding reaction is performed by a rapid heating process using NΗ3 as a reaction gas. 1 2. According to the process of item 10 in the scope of patent application, wherein the above-mentioned nitriding reaction is performed by using Η 2 / Ν at a temperature and pressure of about 500 to 800 ° C and about 1 to 3 Torr. 2 Remote plasma nitridation as a reaction gas. 1 3. —A kind of silicon nitride layer formed on a silicon substrate for subsequent evaporation A gas generation process, which includes at least: placing the silicon substrate in a reaction chamber; sending a mixed gas containing N 20 and Η & into the reaction chamber; and heating a surface of the silicon substrate to a predetermined temperature So that the silicon nitride oxide layer is formed on the heated surface of the silicon substrate. Page 14 478104 6. Scope of patent application 1 4. According to the process of item 13 of the scope of patent application, the above-mentioned mixed gas mainly includes N20. 1 5. The process according to item 14 of the scope of patent application, wherein the above mixed gas package contains Η 2 with a gas ratio of less than 1%. 16. The process according to item 13 of the scope of patent application, wherein the above mixed gas is sent to the reaction chamber with a pressure lower than 10 Torr. 1 7. The process according to item 13 of the scope of patent application, wherein the above-mentioned predetermined temperature is about 800 ~ 1100 ° C. 18. According to the process of claim 13 in the scope of patent application, wherein the thickness of the above-mentioned silicon dioxide layer is less than 15 angstroms. 19. The process according to item 13 of the scope of patent application, wherein the nitrogen content of the above silicon dioxide layer is about 1 to 5 atomic%. 20. The process of item 13 in the scope of patent application, wherein the nitrogen content on the surface of the silicon dioxide layer is about 1 to 5 atomic%. 2 1. The process according to item 13 of the scope of the patent application, wherein the nitrogen content at the interface between the silicon dioxide layer and the silicon substrate is about 1 to 5 atm. Page 15 478104 VI. Application scope of patent 2 2. The process of item 13 of the scope of patent application further includes performing nitriding reaction on the surface of the silicon substrate before sending the mixed gas into the reaction chamber. . 2 3. The process of item 22 in the scope of patent application, wherein the above-mentioned nitriding reaction is performed by a rapid heating process using NH 3 as a reaction gas. 2 4. The process of item 22 in the scope of patent application, wherein the above-mentioned nitriding reaction is performed by using Η 2 / N at a temperature and pressure of about 500 to 800 ° C and a pressure of about 1 to 3 Torr. Remote plasma nitridation as a reaction gas. Page 16