TW519694B - Method for forming MOS transistor with silicide - Google Patents

Abstract

A method for forming a MOS transistor with silicide at least comprises: providing a silicon substrate; forming a dielectric layer on the silicon substrate, such a dielectric layer at least capable of being used as a gate dielectric layer; forming a polysilicon layer on the dielectric layer, such a polysilicon layer at least capable of being used as a gate conductor layer; performing a pattern transfer step to remove a portion of the polysilicon layer and a portion of the dielectric layer to form a gate structure; forming a spacer on the sidewall of the gate structure; doping a plurality of metal particles to the silicon substrate and the polysilicon layer; performing a thermal treatment to convert at least a portion of the metal particles to a silicide layer; and removing the unreacted portion of the metal particles.

Description

519694 V. Description of the invention (1) 5-1 Field of the invention: The present invention relates to a method for forming a metal oxide semi-electric crystal, particularly a method for forming a metal oxide semi-electric crystal which can reduce side effects and control the position of a metal silicide. 5-2 Background of the Invention: Due to the advantages of low resistance, high temperature, and easy combination with polycrystalline silicon, metal silicides have been widely used in the fabrication of semiconductor devices, such as used to connect metals. Part of the interconnect and source drain of the transistor or part of the polycrystalline silicon silicide (po 1 yci de) used as the gate. There are two methods for forming metal silicide in conventional techniques: one is to directly form a metal silicide layer on the substrate; the other is to first form a metal on the substrate and then react the metal and silicon by a heat treatment process And metal silicide is formed. The former method involves reacting a compound containing metal with a metal-containing compound to form a metal silicide, so it is difficult to avoid problems such as by-produce and pollution. For example, when chemical vapor deposition is used to directly form tungsten disilicon (WSi 2), Si 让 and WF are generally allowed to form.

519694

V. Description of the invention (2) (F) Defects to be avoided due to subsequent thermal diffusion of fluorine. WSi y but at this time wSi 2 will contain non-negligible fluorine (especially thermal program). The gate performance will deteriorate. For g ’s by-products and contamination, this method is difficult. The latter method is the gold required to form a metal silicide = sergeant. Therefore, the efficiency of the entire method depends on the process of forming the metal. Metals are generally formed by physical vapor deposition (PVD) (demineralization, evaporation) or chemical vapor deposition (CVD), and the composition of the metal is controlled by evaporation. With the formation of metal with good step coverage, it is not easy to use energy, the step coverage of the formed metal is not good, and the chemical vapor deposition of the plated metal is difficult to avoid as described above. Obviously, this approach is not efficient and easy: shape: problem metal. Obviously, there are many room for improvement in the formation of metal silicides by various techniques, so it is necessary to develop more efficient methods with fewer metal silicides. And effect

5-3 Purpose and summary of the invention: A method for efficiently forming gold The main purpose of the present invention is to propose a method that belongs to the petrochemical industry.

519694, Description of the invention (3) Another purpose of this month is to provide a method that can reduce side effects such as by-products and pollution during the process. It is a lithium oxide. The oxygen semi-electric crystal layer of the present invention has been formed on the silicon substrate to form a polycrystalline silicon electrode. Conductor layer; metal heat treatment is performed on part of the side wall of the structure. Of course, this embodiment of the spar crystal layer at least includes a step of forming a plurality of gold layers on the dielectric layer to remove and remove it. Extending to a better method, on this layer, the dielectric layer of the pattern is performed on the dielectric; doped with multiple procedures, borrowed layers; the Ming can also be a form: provide the layer at least, in this step, so that Pole structure; at least part of the unreacted pattern of the particles is transferred to a metal silicon substrate; as the gate spar layer to the removed part to form a gap slab substrate and these metal parts these steps only move the slab The gold of the compound forms a dielectric dielectric layer; 'It can be used as a free polycrystalline silicon layer wall at the gate junction polycrystalline layer; the particles are transformed into metal particles. Except for the part 5-4 invention details:

In view of various defects in the process of forming metal silicide by conventional techniques, the inventor of the present invention proposes several entry points: First, because the method of directly forming metal silicide must form a metal silicide by chemical reaction, so the reaction The by-products and pollution generated by the process are unavoidable, so it is always necessary to modify the reaction chamber or form a barrier layer on the wafer.

519694 V. Description of the invention (4) Controlling the influence of reactants / contamination. Second, the method of forming a metal before forming a metal silicide through heat treatment, in addition to the metal must be evenly distributed on the wafer to ensure that the metal silicide can be reliably formed, and the metal must be protected from penetrating to the crystal. Depth inside the circle to ensure that the metal silicide does not affect the properties of the semiconductor structure below it. Third, the method of forming the substrate can be arbitrarily adjusted, and the only limitation is the quality of the formed metal. People proposed a method of implantation to form metal-oxygen semi-electricity (particles (metal atoms or metal ions: further heat treatment procedures to form metal lithotripsy should be directly formed), because the implantation method can refine energy, impurity concentration and impurity The layout further ensures that the energy use efficiency of the metal silicide is not as high as the output of the sputtering transistor process (according to these points, the method of inventing the crystal of the present invention: first using a mature technology implantation method) to form metal particles on the wafer · Metal silicide on the surface (or in the surface layer). Since it is not chemically reversed, by-products and pollution can be avoided to control the position of the mixed metal particles, so it can ensure the uniform distribution of the metal; Because the implantation method is so low, the present invention does not cause the entire through-out to decrease. One preferred embodiment of the present invention is a method for forming a golden cow bovine anode with metal silicide, which includes at least the following steps. : As shown in the first diagram A, the Shixi substrate 10 is provided and a dielectric layer is formed.

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It can be used as a gate dielectric layer, and its typical thickness is about 5 " 0 Angstrom. 5. Description of the invention (5) Shi Xi substrate 10, where the dielectric layers 11 to. The dielectric layer 11 is usually an oxide layer, and is up to 300 angstroms. As shown in the first B diagram, multiple days are formed. Here, at least two polycrystalline silicon can be used as ". A typical thickness of 12 is about 500 to 3500 angstroms. On the following day, as shown in the first C diagram, the polysilicon silicon layer performs a polysilicon layer 12 and a portion of the dielectric layer to form a spacer 13 on the side of the gate structure, and removes part of the pattern. 11 to form a gate structure, and then the wall.

卞 十 甘 ° As shown in the figure D, ion implantation technology is adopted. Ϊ́2 = the conventional technology, which is doped with a large number of metal particles 14, for example, the metal ion is an atom, up to 10% on the silicon substrate. Of course, unless it is covered with a photoresist, if not, the metal particles 14 of the knife will also be doped to the gap wall 1 3. As shown in Figures ~ E, a heat treatment process is performed to make the metal particles 2 1 4 react with the Shixi substrate 10 and the polycrystalline silicon layer 12 to form a silicon metal layer 1 of course. The parts in contact with the silicon substrate 10 or the polycrystalline silicon layer 12 ^ metal particles 1 14 will not form a metal oxide layer 15 (these unreacted particles 14 are not shown in the day to simplify the illustration). Generally speaking, the metal silicide f, 15 series is one of the following: titanium disilicide, cobalt disilicide, tungsten disilicide, white disintegration, a disintegration group, and disintegration.

Page 8 519694 V. Description of the invention (6) The type of the silicide layer 15 depends on the type of the metal particles 14. The subsequent step is to remove unreacted portions of the metal particles 14. In order to avoid abnormal short-circuits during subsequent processes such as multi-metal interconnections. Of course, this step can also be extended to remove a portion of the metal silicide layer 15 that is not in direct contact with the silicon substrate. It must be mentioned that the steps from the first C picture to the first E picture can still be modified so that no dielectric layer 11 is removed in the step of pattern transfer. The advantage of this is that in subsequent processes, the dielectric layer 11 can be used as part of other structures that are subsequently formed, such as the gate dielectric layer of the subsequently formed gate. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application. «

Page 9 519694 Brief Description of Drawings Figures A through E are schematic cross-sectional views of the basic steps of a preferred embodiment of the present invention. Symbols of the main parts ... 10 Silicon substrate 11 Dielectric layer 12 Polycrystalline layer 13 Gap 14 Metal particles 15 Metal silicide layer

Claims (1)

519694 6. Application patent scope 1. Method for forming gold-oxygen semi-electric crystal with metal silicide, including at least: providing a substrate; forming a dielectric layer on the silicon substrate, the dielectric layer At least as a gate dielectric layer; forming a polycrystalline layer on the dielectric layer, the polycrystalline layer can be used as at least a gate conductor layer; performing a pattern transfer step to remove it Part of the polycrystalline silicon layer and part of the dielectric layer to form a gate structure; forming a gap wall on the side wall of the gate structure; doping a plurality of metal particles to the silicon substrate and the polycrystalline silicon layer; A heat treatment process is performed to transform at least a portion of the metal particles into a metal oxide layer; and remove an unreacted portion of the metal particles. 2. The method according to item 1 of the scope of patent application, wherein the above-mentioned dielectric layer is an oxide layer. 3. The method according to item 1 of the scope of patent application, wherein the thickness of the dielectric layer is about 50 angstroms to 300 angstroms. 4. The method according to item 1 of the scope of patent application, wherein the thickness of the polycrystalline silicon layer is about 500 angstroms to 3 500 angstroms. 5. The method as described in item 1 of the scope of patent application, wherein the above-mentioned metal particles 519694 6. Scope of patent application The grain system is one of the following: metal ions and metal atoms. 6. The method according to item 1 of the scope of patent application, wherein the above-mentioned metal particles are doped with ion implantation technology. 7. The method as described in item 1 of the scope of patent application, wherein the above-mentioned metal silicide layer is one of the following: titanium disilicide, cobalt disilicide, tungsten disilicide, platinum disilicide, two stone dispersants, two Tantalum silicide and disilicide. 8. The method described in item 1 of the patent application scope further comprises removing a portion of the metal silicide layer that is not in direct contact with the silicon substrate. 9. A method for forming a metal oxide semi-transistor with a metal oxide, at least comprising: providing a silicon substrate; forming a dielectric layer on the silicon substrate, the dielectric layer being at least a gate A polar dielectric layer; forming a polycrystalline silicon layer on the dielectric layer, the polycrystalline silicon layer can be used as at least a gate conductor layer; performing a pattern transfer step to remove a portion of the polycrystalline silicon Layer to form a gate structure; forming a gap wall on the side wall of the gate structure; doping a plurality of metal particles to the silicon substrate and the polycrystalline silicon layer; performing a heat treatment process so as to at least part of the metals Granules Page 12 519694 VI. Scope of patent application Turning into a metal oxide layer; and removing unreacted part of these metal particles. 10. The method according to item 9 of the scope of patent application, wherein the above-mentioned dielectric layer is an oxide layer. 11. The method according to item 9 of the scope of patent application, wherein the thickness of the dielectric layer is about 50 angstroms to 300 angstroms. 12. The method according to item 9 of the scope of the patent application, wherein the thickness of the polycrystalline silicon layer is about 500 angstroms to 350 angstroms. 13. The method according to item 9 of the scope of patent application, wherein the above-mentioned metal particles are one of the following: metal ions and metal atoms. 1 4. The method according to item 9 of the scope of patent application, wherein the above-mentioned metal particles are doped with ion implantation technology. 15. The method as described in item 9 of the scope of the patent application, wherein the metal silicide layer is one of the following: titanium disilicide, cobalt disilicide, tungsten disilicide, platinum disilicide, two stones, Two silicided groups and two silicided handles. 16. The method according to item 9 of the scope of patent application, further comprising removing a portion of the metal silicide layer that is not in direct contact with the silicon substrate. Page 13