TWI250589B - Method for improving doping profile of lightly doped source/drain - Google Patents

Abstract

The present invention disclose a method for improving doping profile of lightly doped source/drain, which employs the wet etching on the lining layer and the lightly doped sacrifice layer after dry etching; then, employing the isotropic etching theorem of wet etching to form a residual lining layer and a residual lightly doped sacrifice layer; next, employing the gate structure, the residual lining layer and the residual lightly doped layer as a mask for conducting the source/drain doping process with lower density; and, conducting the doping atom diffusion driving to obtain a lightly source/drain extension doping region with better inclined profile.

Description

1250589 V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a method for performing light ion doping of a pair, an original/square Φ pair, an original person, and a polar region, particularly regarding a process that can be applied to a process. A method of forming a preferred source/no very light ion doping profile after size entry. Unreleased [previous technology]

When the semiconductor element is born, 隹λ d subiearOtil ′ to deep sub-micron (deeP — η) to effectively reduce = light f-heterogeneous pole (11 unloading y d_d length becomes shorter, will be produced / pass

The lower part is the high electric field, so the most relatively large, and the positive side of the gate side wall will cause light mixing; the electric free phenomenon' at this time the thermoelectricity increases, causing LDD-specific degradation mode & the domain is depleted, and As a result, the light-doped bungee has the above problem due to the tempering of the LDD Thunder Ship and the Emperor L region. For the lightly doped bungee region below the body + side soil, the Overlap LDD transistor surname is 槿乂 乂 , , , , , , , , 所以 所以 所以 所以 所以 G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G The positive voltage applied to the gate during the operation of the drain region allows the light method to be injected into the side wall to reach the right j, so that the resistance is lowered, so that the hot electrons will be absent. Please refer to the suppression shown in the first figure. Degradation mode. The pole structure 10 (sometimes also: the Gate 0ver lap LDD system uses the gate) for the LDD process to add the oxide layer of the etched gate to the etched gate. The outline of the hybrid region will go straight into the mask. The light-doped anti-u-di-f A) pattern formed by the method shows the ion concentration and the received thermal driving energy.

Page 5 1250589 V. Invention Description (2)-- The light-doped bungee region heterodymium region t M ^ contour is formed as the second (β) map f & know the process ίί 靡 靡, by In the second (B) diagram, the lightly doped J ^ ^ can not form 6 M ^ can be clearly found in the sub-micron, so not inclined extension profile, and the improvement of the process and enthalpy effect is not perfect control extension The outline of the area is short-circuited and thermoelectric. Therefore, the method of the present invention is to solve the above problems: to improve the shallow hedges [the improvement of the imperfections in the invention]. The principle of T to short-pass the main doping profile of the present invention is to provide an improved light doping source/no wet etching, and the use of the counter substrate layer and the lightly doped sacrificial screen. Using the brakes, the lightly doped sacrificial sputum is used as the mask, and the i% 彳-_~ structure, the remaining substrate layer and the remaining lightly doped g ^ 极 extremely light ion 仃; 仃 light doping and extreme process to obtain - , 2 sacrificial layer: in the doping profile. Line #又好的源/汲 The other part of the invention - the extreme doping in the purpose 'is to provide a way to change the cover 4 Α 婵丄 婵丄 ,, J: 私客 t and good light doping source / 汲 micro : Can not be processed after the process; the improvement of the known process into the deep doping wheel ί: "The purpose is to provide - a change in C. The production produced by:: * * ' can effectively avoid the element; the source / 汲 I of the invention Ϊ channel and thermionic effect. The size of the gradually smaller J-doped profile is provided as a # improve and replace the 半 半 半 半 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , —Several isolation-ion^~匕 contains a gate oxidation page 6 1250589 — —— V. Description of invention (3) | Layer and the polycrystalline layer above it ^ 丨 丨 轻 轻 轻 轻 轻, ,,. Forming the sidewalls - lightly doped: the two f-substrate I-mole sacrificial layer and the "two:: substrate layer are etched to form: sacrificial layer; h layer and residual oxygen layer into the gate... gate = 丨一轻, 杂 = The number of ion 乂丨 个 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 区域 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The oxide layer of the gate and the polycrystalline crystals above it are engraved, and the sacrificial layer is lightly doped, and the light is ##日, and the remaining layer of the light and early sacrificial layer into the sacrificial layer is covered by the sacrificial layer. Curtain, p sacrificial layer, gate structure fish 兮 ± : bottom opening...: perform a low concentration ion implantation, Γ ί lightly doped I ii into a lightly doped source/drain region. In the semiconductor base lli ^ ^ I Review Committee for the purpose of the present invention, # Λ detailed description, two; with a better 丨 method this t:::: - improved light doped source / immersion profile The doping process can be better: for the first step, please first check the Chu-闽 & - heart, miscellaneous / and polar contours. There are a plurality of 4, which are preceded by the active element in the _ body substrate of the semiconductor substrate 2 and are = 丨 22, and then the beam path. ° or Shall〇W trench isolation, STI), the surface of the + conductor substrate 20 is formed with a gate oxide layer and a bit 1250589. 5. Description of the invention (4) On the gate oxide layer 2 4 on the eve of the splicing system II: j:: = damage caused by the gate structure 28 ± 2 ,, can be taken; guided by the semiconductor-based process to form - Diding only ° Haifeng conductor substrate 20 to a (CVD) semiconductor %/ 〇, then, using chemical vapor deposition, sacrificial layer 32, its thickness / bottom 2 deposited a material on the surface of yttrium oxide &yt; use chores = ~ coffee A. The light-heavy heterogeneity on the substrate 20 is mostly deposited on a semiconductor to be removed to form a thickness based on the deposited thickness: using a chlorine acid or a faint; 1 diluted hydrogen is not left over the lightly doped sacrificial layer 34, this day t to form a material such as the fifth = sacrificial layer 32 is also b, because the substrate layer 30 is lightly etched - and removed A portion of the substrate is thus lightly doped to the sacrificial underlayer 36. ^Knife bottom layer 30, formed - the remaining lining with the gate structure 28, the remaining 铪酤 为 罩 罩 , , 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体Source/amplitude source/drain ions. Forming a lightly doped source/drain region 38 in the bottom 20, please refer to the lightly doped source diagram formed in the sixth (A) and sixth modes, which will be significant in the fifth (A) of the present invention. The enlarged outline of the region (9), during the sub-planting, the gate structure 28, the low-concentration source/drain isolation layer 36 will effectively block the low-concentration ion f ^ impurity sacrificial layer 34 and the remaining substrate ^ ' To obtain a better lightly doped source / 125 〇 589 ° region, 3 8 contour ^ region 埤, and then to the semiconductor substrate 2 k 执 Ϊ Ϊ 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子 离子Into a traitor, the steepness of the pure eight, your slanting diffusion, to the shape, such as the fifth (B) g knife - the gate is heavy and lightly doped source / bungee region wheel, on the side wall of the structure In order to solve the problem that the length of the channel becomes shorter, the gate: 扉 抖 2 2 is electrically discharged, the peak produced & M pole: :: extremely degraded mode. J-diluted hydrogen fluoride injected into the side wall: ;:::;:: =:1 Example: 1~100: ! Excess = blending: sacrificial layer 34 and row engraving, to directly use chemical = repair Oxidation is made by teeth, and 3. 〇~iOOOA. The eucalyptus layer 32' has a large thickness as shown in the seventh figure. Using dry remnants, the female... sacrifice layer, ... the light doping on the thick conductor substrate deposited as shown in Figure 8 is removed by light doping =, ^ 2 to form a dilution ratio of 10: Bu, 9 32 outline, and then hydrofluoric acid or the liquid layer 32 is wet etched to dilute the hydrofluoric acid solution to the lightly doped sacrificial layer. y into the remaining light junction as shown in the ninth figure and then the interfacial junction 9 2 'conductor substrate 20 into the 杵, = lightly spread the sacrificial layer 34 as a mask with low difficulty of the immersion / source ion implantation To make it 1+

KM $9 page 1250589 V. DESCRIPTION OF THE INVENTION (6) A lightly doped source/drain region 3 8 is formed in the semiconductor substrate 20. Then, a tempering process for diffusing ions of the lightly doped source/drain region 38 is performed on the semiconductor substrate 20 to form a lightly doped source/no-polar region with an excellent extended profile, and then reused. Hydrogen fluoride or a dilute hydrofluoric acid solution having a dilution ratio of 10:1 to 1 0 0:1 wets the semiconductor substrate 20 to remove the remaining lightly modified sacrificial layer 36. Of course, after the lightly doped drain process is completed, a high concentration ion implantation and metal germanium process can be successively performed, but the technical feature of the present invention is light ion doping implant to obtain a lighter extended profile. The method of doping the source/drain region, so this is not described in detail for subsequent processes. The present invention is a method for improving the doping profile of lightly doped source/dip ions, which is effective. After the conventional process is entered into the deep submicron stage, the gate is lightly doped with a drain extension process, and the missing contour of the extended extension region cannot be obtained, and the channel length is shortened, thereby preventing the channel length from being shortened. The conductivity of the channel becomes large, and the injection of hot electrons into the sidewall of the gate causes a lack of light-doped regions. However, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, the shape, structure, characteristics, and spirit of the present invention are equally varied. And modifications are intended to be included in the scope of the invention.

Page 10 1250589 Brief Description of the Drawings [Simplified Schematic] The first figure is a cross-sectional view of a gate structure with extended shallow ion doping. The second (A) diagram shows the appearance of a light ion doped profile of a conventional process. The second (B) pattern is the outline appearance of a conventional light ion doped region after a tempering process. 3 to 5 are cross-sectional views showing the steps of the present invention. The sixth (A) diagram is the appearance of the light ion doped profile of the present invention. The sixth (B) diagram is the outline appearance of the light ion doped region of the present invention after the tempering process. 7 to 9 are cross-sectional views showing the steps of another embodiment of the present invention. [Main component symbol description] 1 0 gate structure 1 4 lightly doped source/drain region 2 0 semiconductor substrate 2 2 shallow trench isolation region 2 4 gate oxide layer 2 6 polysilicon layer 2 8 gate structure 3 0 substrate layer 3 2 lightly doped sacrificial layer 3 4 remaining lightly doped sacrificial layer 3 6 remaining substrate layer 3 8 lightly doped source / drain region

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Claims (1)

1250589 6. Patent Application No. 1 - A method for improving the doping profile of a lightly doped source/drain, comprising the steps of: providing a semiconductor substrate having a plurality of isolation regions formed therein; forming on the semiconductor substrate a transistor gate structure; forming a substrate layer on the semiconductor substrate; forming a lightly doped sacrificial layer on the sidewall of the gate structure; etching the lightly doped sacrificial layer to form a remaining lightly doped sacrificial layer Etching the substrate layer to form a remaining liner oxide layer; and performing a low concentration ion implantation with the gate structure, the lightly doped sacrificial layer and the remaining oxide layer as masks A lightly doped source/drain region is formed within the semiconductor substrate. 2. The method of improving the doping profile of a lightly doped source/drain according to claim 1, wherein the semiconductor substrate is tempered after the lightly doped source/drain region process is completed. The process is performed to diffuse dopant atoms to form an extended lightly doped profile and reform the fractured atomic structure of the surface of the semiconductor substrate. 3. The method of improving the doping profile of a lightly doped source/drain according to claim 1, wherein the step of forming the lightly doped sacrificial layer comprises the steps of: depositing on the semiconductor substrate a ruthenium oxide layer; and the ruthenium oxide layer is dry etched to form a lightly doped sacrificial layer on the sidewall of the gate structure. 4 · Improved lightly doped source / bungee as described in item 3 of the patent application Page 12 1250589 VI. Patent Application The method of doping a profile, wherein the yttrium oxide layer is formed by a chemical vapor deposition method. 5. The method of improving the doping profile of a lightly doped source/drain according to claim 1, wherein the lightly doped sacrificial layer is etched using a wet etching technique. 6. A method of improving a lightly doped source/dipole doping profile as described in claim 5, wherein the wet etchant is selected from the group consisting of hydrofluoric acid or dilute hydrofluoric acid solution. A method for improving a doping profile of a lightly doped source/drain, comprising the steps of: providing a semiconductor substrate having a plurality of isolation regions formed therein; forming a gate on the semiconductor substrate a pole structure comprising a gate oxide layer and a polysilicon layer thereon; forming a lightly doped sacrificial layer on the sidewall of the gate structure; etching the lightly doped sacrificial layer to form a remaining lightly doped sacrificial layer; A low concentration ion implantation is performed with the gate structure and the lightly doped sacrificial layer as a mask to form a lightly doped drain region in the semiconductor substrate. 8. The method of improving the doping profile of a lightly doped source/drain according to claim 7 of the patent application, wherein the semiconductor substrate is tempered after the light doping and polar region process is completed a process for performing diffusion of dopant atoms and reforming the germanium atomic structure of the surface of the semiconductor substrate Page 13 1250589 6. Patent Application No. 9: A method for improving the doping profile of a lightly doped source/drain according to claim 7 of the patent application, wherein the step of forming the lightly doped sacrificial layer includes The following steps: depositing a hafnium oxide layer on the semiconductor substrate; and dry etching the germanium oxide layer to form a lightly doped sacrificial layer on the sidewall of the gate structure. A method for improving the doping profile of a lightly doped source/drain according to claim 9 wherein the yttrium oxide layer is formed by a vapor phase deposition method. 1 1 . The method of improving the doping profile of a lightly doped source/drain according to claim 7, wherein the lightly doped sacrificial layer is etched using a wet etching technique. The method of improving the doping profile of a lightly doped source/drain according to claim 1 wherein the wet etchant is selected from the group consisting of hydrofluoric acid or a dilute hydrofluoric acid solution. Page 14