TW313678B - Method of forming polysilicon salicide metal gate - Google Patents

Abstract

A method of forming salicide gate comprises of the following steps:(1) forming one gate oxide on one substrate; (2) forming at least one polysilicon on the oxide layer; (3) implanting ion on the polysilicon; (4) forming one salicide on the polysilicon; (5) implanting ion to the salicide layer and the polysilicon layer;(6) patterning and etching the salicide, the polysilicon and the oxide;(7) patterning one gate electrode patterned by one photoresist; (8) forming source/drain region, and the source/drain region uses the gate electrode as mask.

Description

A7 B7 5 ;: Description of the invention (5-1 Field of invention: Law, particularly popular ^ Fang, Ministry of Economic Affairs, Central Standards Bureau, Employee Consumer Cooperative Printed 5-2 Background of the invention:, Metal oxide semiconductor (MOS) structure for modern semiconductors Design. Any MOS field-effect transistor has two points. "Flaw" is everywhere, and the poles are three. The _ system passes the capacity "when a voltage is applied to the ridge". The base of the _ charge is under the paste electrode. There is a thin layer of oxide between the gate metal and the inverted substrate. Shangdian metal polycrystalline (MOS) technology has been used to make high-efficiency gate electrodes including a thin layer of oxide oxide on the top layer. The metal Wei Wuqing is formed on polysilicon to Reduce the series resistance between polysilicon and interconnects. Furthermore, in the REFLGW leveling: _t, metal ____ metal can withstand / m liters. Inadequate, there are some by-product impurities in the metal dreaming process, For example, fluorine atoms in the process of forming tungsten silicide (WSix) will diffuse into the gate oxide after tempering at high temperature. The thicker the gate oxide, the slower the device's speed and the higher the starting voltage. McCaw SLHsu Etc., Direct evidence of gate oxide th ickness increase in tungsten polycide pr〇cesses ,, J IEEE Electron Device Letter, Vol. EDL-12, 1 " 1, page 623_625. What is more, the above-mentioned fluorine atoms apply this paper standard to the Chinese National Standard (CNS ) A4 specifications (2 丨 〇 < 297mm) t Please read the precautions on the back before filling in this X). I -----. I ..... 1 ....... . ———- 11! 1- 1-I —1 i. Order ------ ^ ---- --IJ-Λ ffim fm ml UK— —i-li 1 313678 A7 B7 _ V. Invention Description () Causes lateral distribution in the tungsten silicon gate, further deteriorating the device characteristics. Refer to H. Hayashida et al.'S "Dopenf redistribution in dual gate W-polycide CMOS and its improvement by RTA,?, VLSi Symp.Tech Dig. 1989. 5-3 Purpose and overview of the invention: including forming a gate oxide on the substrate Layer, at least a polysilicon layer is formed on the gate oxide layer, and ion implantation is performed on the metal silicide and polysilicon to make a mask pattern and the remaining metal oxide layer and polysilicon layer to separate the gate region and the gate The area acts as a source / drain area for implantation of the military curtain. 5-4 Brief description of the diagram: With the help of the following detailed description and the accompanying drawings, the aforementioned aspects and the advantages of the present invention can be obtained immediately. The drawings are as follows: Figure 1 to Figure 5 are cross-sectional views of the structure of each stage of manufacturing a metal stone evening gate in accordance with the present invention. Figure 1_ shows the structure behind the gate oxide grown on the substrate. The first picture_shows the deposition of the two layers of polycrystalline stone and the structure after the first nitrogen ion implantation. n ^ l- · ^ ϋ.— m ^ — —ϊ ^ v 'ΧΎ— (Please read the precautions on the back before filling out this page) Ιτ AT .. Printed by the Employee Consumer Cooperative of the Central Bureau of Standards, Ministry of Economic Affairs) A4W 21〇 ~ ^^ 7 ^ 13678 " ~~ ------——, Description of the invention (A7 B7 third structure _ shows the field of provocation after tungsten silicide deposition and the application of secondary nitrogen ion implantation Figure 5 shows the pattern of the photoresist. Figure 5 shows the metal stone evening structure and the corresponding source / no zone according to the present invention (gold: two :: this: clear: shows the formation of self-aligned polycrystalline dreams. Figure 6 is shown in The structure of the silicon dioxide layer after sinking. The structure of the mth according to the present invention shows the accuracy (metal stone evening compound) of the 5-5 invention. Detailed description: (read the precautions on the back of the poem before filling in this page)

------ OT n ^ l 1— ϋ- I Kn I " A! Printed by Uncle Consumer Cooperative, Central Bureau of Standards, Ministry of Economic Affairs. The cross section of the isolation area 12 of the first substrate is shown. These isolation areas I2-Bian Youdian Wei Lu, (3) thickness ~ ~ ⑽ ⑽, in the base private 10 ^ is a layer of thin layer of oxide cut 14, said after this layer is used as a gate oxide to isolate the conductor from the semiconductor County Board 1G. According to Newton, this thin layer of U2 TiO2 has a wealth of materials. Typical_Thin oxide

A7 B7 V. Description of Da Ming (The traditional thermal oxidation process is used for growth exploration, its thickness is about 30-250 1 〇 The Ministry of Economic Affairs Bureau of Standards and Consumers of the Ministry of Consumer Cooperation Du Yinfu and the first-^: shown there are more than two layers Jingban, that is, the first-polycrystalline gift 16 f first-multiple 4 layers 18, both of which are mixed with the vapor deposition process at low pressure (〇, 卜托托) and temperature tree ~ 625 1 decompose hair fever (coffee) The first-polycrystalline shop 16 and the second polycrystalline pin 18 thus formed have a thickness of about 50 OA and 1000 A, respectively. As everyone knows, no matter whether it is a layer of polycrystalline silicon or more than one layer of polycrystalline stone, it has not diverged The spirit of the patent scope achieves the purpose of the present invention. The reason for depositing the polycrystalline layer is to reduce the resistance β between the polycrystalline name and the metal petrified metal. Please refer to the page of H · ΥΕΝ's work, Thermal Treatment and under layer effects on silane and dichlorosilane based tungsten silicide for deep sub-micron interconnection processes ", VLSI Technology 'System and Application, 1995. This stacked polysilicon structure has been revealed to prepare the smooth gate surface for reducing internal resistance. SLWu% "Characteristics of polysilico. Η contacted shallow junction diode formed with a stacked-amorphous silicon film", IEEE Electron Device, ED-40, 1993, pages 1797 ~ 1803. The next step of ion implantation 20 is done in Figure 2 The structure shown. The nitrogen atom has an implantation energy of 20 ~ 100 kiloelectron volts (KeV) and the applied dose is 1 * 1015 ~. The amount of energy depends on the thickness of the polysilicon, so that its implantation profile peak value is about The second layer of polysilicon IS is halfway through. It is well known that '5 papers are made with the Chinese national standard falcon (CMS> A4 specifications (nOX29) mm) (please ^ read the notes on the back and fill in this page)

T.I --- I Order A7 B7 V. Description of the invention () Others such as atomic argon, germanium and Shixi can be used instead of nitrogen to achieve the same purpose of the present invention. As shown in FIG. 3, the next step is to deposit the WiseX layer 22, which has a thickness of about 0 ~ 200 A. Tungsten metal M is simultaneous sputtering or chemical vapor deposition (CVD) of silicon tungsten. A typical heat treatment for deposition later is to put it in a furnace, or use rapid thermal processing (RTP) for tempering to achieve a uniform composition and crystallize this layer into the desired high-conductivity electrically conductive metal stone evening compound. In this RTP tempering process, the crystal circle rapidly rises from a low temperature to 700 to 1100. The wafer continues at this temperature for one = time, and then returns to a low temperature at a rate of about 100 ~ 30G ° C / sec. Compared with the heating furnace, it takes 12 minutes, and the RTP treatment is reduced to less than 30 minutes. The connecting step is to perform another ion implantation 24 on the structure shown in Figure 3 6. More desirably, the nitrogen atom has an implantation energy of 50 to 15 kiloelectron volts and an applied dose of 1x1015 to 5x1016 at〇ms / cm2. How much energy is used The oligoskirt depends on the thickness of the polycrystalline single, so that the peak value of its implanted contour is about halfway to the second polycrystalline stone evening layer 18. Other atoms such as argon, germanium and nitrogen are used instead. It is worth noting that the second and third _ continuous sub-ion borrowing steps are used to overcome the difficulties encountered in the traditional process, and the ^ section of the original expression leads to _ and the importance of impurities in the shirt secret 2 2 „Knowledge of two implantation steps and only -second step—- I--* ----- (please read the precautions on the back first and then fill out this page j ^ 'sad ------ Order the Beigong Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs_Paper Money Xiaoling (CNS) A4 ^ ~ 210X297mm, which has the same purpose as the present invention) Employee Cooperative of the Central Bureau of Economics of the Ministry of Economic Affairs A7 B7 V. Description of invention ( ) Later, as shown in Figure 4, a layer of photoresist layer 26 with a gate pattern is formed on the silicon oxide layer 22, and the pattern is determined by standard processes such as photoresist coating, exposure, and development. The pattern 26 is used as a cover screen. After the engraved scale dream layer 22, the second layer of polycrystalline stone evening layer 18, the first layer of polycrystalline stone evening layer I6, and the thin layer of silicon dioxide evening layer 14, the figure 5 shows the finished product Next, the structure in Figure 5 withstands an ion implantation 28, with an implantation energy of about 6 kiloelectron volts and a primary dose of about 6xl015crfcww / cm2. Regions 29A and 29B. A metal silicide gate structure with improved gate oxide characteristics is then formed. Figures 6 and 7 show the steps that can be selected at will. The method is to form a self-aligned metal with a metal oxide gate structure Polycrystalline sintered metal gate (metal sintered metal gate). This structure combines the characteristics of self-aligned metal silicide gates. In Figure 6, a layer of silicon dioxide 30 or nitride The silicon layer 30 is formed. The silicon dioxide layer can be perfectly decomposed and formed with tetrahexyl silicate TEOS (Si (C2H50) 4) at 65 ~ 75〇10. The silicon dioxide layer 30. Then The spacers are formed by anisotropic etching, as shown in Figure 7 on the side walls of the gate. These spacers 30 are used as the implantation screen for the next source / drain 29A and 29B weight ion implantation 32 The final structure finally formed a self-aligned metal polysilicide (metal silicide) gate structure with improved gate oxidation characteristics. The results of nitrogen atom implantation are shown in Table 1.-_________ 7 Paper size Applicable (Sutengli I ^ ------- rs clothing ------_ lτ ------ ^ 1 (Know first Note to fill out the back of this page)

A7 B7 V. Description of the invention (The first N implantation, the second N implantation, the energy dosage, the energy dosage, the energy dosage, Ebd (MV / cm), Tbd (seconds), 12 MV / cm, polysilicon gate 72.1 25, 2E15 -1 L 16.6 269 Polysilicon gate 82.1 25 5E15 None 14.59 85 Metal polysilicon gate with N implant 74.7 ί% '80 2E15 16.25 300 Metal polysilicon gate with N implant 73.3 None 80 5E15 16-4 641 Metal polysilicon dream: gate N implant 76.1 None 4% 16.06 307 Metal polysilicon gates N implant 73.1 None None 16,59 > 10000 (Please read the precautions on the back before filling this page) I 《衣 ---- _ ^ | This Printed by the Employee Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs ^ As shown in the table, when the control sample is only a standard polysilicon gate, it has a gate oxide thickness of 72.1A 'Banji Electric Field (Ebd) 16.6meg.V / cm and a crash time (Tbd) 269 In the second, when the first layer of nitrogen implantation or the second layer of nitrogen implantation is used, the increased gate oxidation rotation is mixed with Chuanlan polycrystalline Lai, and other electrical characteristics are also similar. The examples have been demonstrated and stated , All other rhetoric that does not deviate from the disclosure of the person β 'under% of the present invention should be included in the following Within the range of 0 to patent applicable Central sheets from Falcon (CNS) A4 size (210X297 mm) -i-raj λ

Claims (1)

A8 B8 C8 D8 ------------ VI. Scope of patent application 1.-A method for forming metal stone evening compound gate, the above method includes the following steps: forming a gate oxide layer in A substrate; forming at least one polysilicon layer on the oxygen dagger layer; implanting ions on the polysilicon layer; forming a metal silicide layer on the polysilicon layer; implanting ions on the metal silicide layer and the polysilicon On the layer;, the metal silicide layer and the polysilicon layer are etched and etched to define a gate region with the oxide layer, and the gate region is defined by a photoresist; and the source / drain region is formed, the source / The drain region uses the gate region as a mask. 2. As in the first method of applying Fan Gu, in which the implantation sources for implanting ions into the above polysilicon layer include nitrogen, argon, germanium and dream, and combinations thereof. 3. The method according to item 1 of the application scope, wherein the implantation sources for implanting ions in the metal silicide layer and the metal polysilicon layer include nitrogen, argon, germanium, silicon and combinations thereof. Printed by the Employee Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs — ^-. · '----- (installed-- (please read the item ##' on the back and fill in this page first) 4. If applying for Fanyuan A method, in which the above metal silicide layer is a tungsten silicide layer. 5. The method as in the first item of the application scope, further includes: This paper button Gu quietly 313678 AS B8 C8 — _ _ A. Patent application Forming a dielectric layer on the metal silicide layer and the source / drain region; #directionally etching the dielectric layer to form a spacer on the side wall of the gate region; and forming a concentrated implant source / The dip region, the concentrated implant source / drain region uses the spacer as the military curtain. 6. As in the method of item 5 of the application scope, where the above dielectric layer is a layer of silicon dioxide. 7. As in the application model The method of item 5, wherein the above dielectric layer is a nitrided dream layer. 8. A method of forming a metal silicide gate, the above method includes: forming a gate oxide layer on a substrate; forming At least one polysilicon layer on the oxide layer; implant ions on the polysilicon layer; form a layer of gold A stone silicide layer on the polysilicon layer; implant ions on the metal silicide layer and the polysilicon layer; pattern and etch the metal silicide layer on the polysilicon layer and defined by the oxide layer A gate area, the gate area is defined by a photoresist; and a source / drain area is formed, and the source / drain area uses the gate area as a mask. 9. The method as described in item 8 of the scope of application , Where the implantation sources for implanting ions into the above polysilicon layer include nitrogen, argon, germanium, and Shi Xi and their combinations. (Please read the precautions on the back before filling out this page) --- (Shang ·,? Τ_ Ministry of Economic Affairs The printed copy of the paper is suitable for the National Standards (CNS) A4 specification (210X297 public meals ~~-The Ministry of Economic Affairs of the Ministry of Economic Affairs of the Ministry of Economic Affairs of the Ministry of Economic Affairs A8 B8 C8--D8). Application Patent scope " ~~: '~~ 10. As in the method of item 8 of the application scope, the above metal silicide layer is a dreaming layer. 11. As in the method of item 8 of the application scope, it further includes: Forming a dielectric layer on the metal silicide layer and the source / drain region; Etching the dielectric layer to form a spacer on the sidewall of the gate region; and forming a dense implant source / drain region, the dense implant source / drain region is based on the spacer. 12. If the scope of application The method of item 11, wherein the above-mentioned dielectric layer is a silicon dioxide layer. 13. The method of item 11 of the scope of application, wherein the above-mentioned dielectric layer is a vaporized stone evening layer. 14. A metal polycrystalline stone evening party The method of compound gate, the combination of the upper Shu method · forming a gate oxide layer on a substrate; · forming at least one polysilicon layer on the oxide layer; implanting ions on the polysilicon layer; forming a layer of metal silicide The object layer is on the polysilicon layer; the ions are implanted on the metal silicide layer and the polycrystalline hair layer; the metal dream compound layer and the polycrystalline broken layer are patterned and described and the oxide layer defines a gate The region, stomach and _ region are-light P and defined; and form a source-level electrode region, the source / non-electrode region uses the gate region as a mask. The size of this paper is applicable to the Chinese National Standard (CNS) A4 specification (2 mm 297 mm) 11-; ----- (. 装 ------ 、 玎 ------ 1 (please read first (Notes on the back and then fill in this page) ^ 13678 Patent application scope = second scope method, where the above-mentioned metal silicide layer is ^ as the method of applying Lai M, and further includes: a two-layer dielectric layer on the metal Wei Xun and above /. Forming a spacer on The side wall of the idle pole area ;, the curtain is formed into the concentrated human source. The 7th area is the dip wall as the money, where the upper wire _ one layer two = the 17th method of the stone application scope, where the above dielectric layer is -Layer Nitrogen • HI m · fm —ii m. (Please read the note ^ 'on the back and then fill in this page) --- (Binder --- ^ — printed by the employee consumer cooperative of the Ministry of Economic Affairs ^ --- Regulation I Ligong 7 9 2