TW531851B - Method of forming a rugged polysilicon layer on a semiconductor substrate - Google Patents

Abstract

The present invention provides a method of forming a rugged polysilicon layer on a semiconductor substrate. Firstly, a polysilicon base layer is formed on the semiconductor substrate, then a thin chemical oxide layer is formed on the polysilicon base layer by using an oxidizer, the thin chemical oxide layer is processed by using silicon or argon sputtering method and secondly, a rugged polysilicon layer is grown on the surface of the thin chemical oxide layer.

Description

531851 V. Description of the invention (1) Field of the invention The present invention relates to integrated circuit (ICs) process technology, in particular to surface pretreatment by silicon or argon sputtering, and then forming thick chains on a semiconductor substrate. The method of polycrystalite evening layer (rugged P 0 1 ysi 1 ic n). Description of the Related Art Rough-surfaced polycrystalline silicon, also known as hemispherical grained silicon (HSG), has a doubled surface area, so it is often used in dynamic random recess random access memory (dynamic random recess random; DRAM) lower electrode plate to increase the capacitance of the capacitor. The flow chart of growing rough polycrystalline silicon and its pre-processing shown in Figure 1 is used below to explain the conventional technology. First, a polycrystalline silicon underlayer is deposited over the semiconductor substrate. Then, the buffer oxide oxidation etchant or diluted hydrofluoric acid is used to remove the native oxide, and then a mixed solution of oxidant ammonia and hydrogen peroxide (also (Referred to as SCI) and / or a mixed solution of hydrochloric acid and hydrogen peroxide (also known as SC2) to treat the surface of the underlying polycrystalline silicon to form a chemical oxide thin layer (chemical oxide) on the surface of the underlying polycrystalline silicon. The oxidized thin layer can be used as a buffer layer, and can contribute to the grain shape, adhesion, and grain density of the coarsely grown polycrystalline stone. Next, a rough polycrystalline silicon layer is formed on the surface of the chemical oxidation thin layer.

531851 V. Description of the invention (2) = However, the rough multicrystalline silicon layer is formed by the above-mentioned conventional process. The process has insufficient elasticity, and it is difficult to control the shape and density of the crystal grains. Furthermore, the adhesion between the rough polycrystalline silicon and the underlying polycrystalline silicon is still insufficient. • I Ϊ t, using the process of the above-mentioned conventional technology to form a coarse polycrystalline spar layer, and it takes a long series of standard cleaning for pre-treatment. SUMMARY AND OBJECTS OF THE INVENTION In view of this, an object of the present invention is to provide a method for forming a rough polycrystalline silicon layer on a semiconductor substrate, which can improve the flexibility of the process, and control the shape and density of the crystal grains. In addition, another object of the present invention is to provide a method for roughing a polycrystalline silicon layer in a semiconductor device, which can improve the adhesion of the rough polycrystalline silicon: the bottom layer of the polycrystalline silicon. 7 ^ = ′ Another object of the present invention is to provide a method for forming a rough polycrystalline silicon layer on the bottom of the soil. Private soil string > monthly washing and separate treatment to achieve the effect of simplifying the process. According to the above object, the present invention provides a method for forming a coarse sugar polycrystalline stone layer, at least a polycrystalline stone is formed above a square body substrate on a conductor substrate; and a step of forming a chemically oxidized thin layer on the semiconductive substrate The thin layer of the polycrystalline silicon silicide; the thin film of the above chemical oxidation; = oxygen, furthermore, the rough polycrystalline silicon layer having a length of ten lambs in the semiconductor. In the method, the oxidant is a mixed solution of ammonia water and: oxygen: = rough polycrystalline silicon layer and hydrogen peroxide. Flying mixed 5 solution, or hydrochloric acid. Furthermore, the above-mentioned method for forming a crude sugar polycrystalline spar layer above a semiconductor substrate. Page 5 0725-7546TW (N); 1-01-006; Jessica.ptd 531851 5. Description of the invention (3) A method in which a primary oxide layer is formed on the surface of the above-mentioned polycrystalline silicon bottom layer. In other words, before forming the rough polycrystalline silicon layer 1 on the semiconductor substrate, before the treatment with the oxidant, the method further includes the step of removing the primary oxide layer by using a buffer etchant or a hydrofluoric acid solution. In addition, the above-mentioned method of forming a rough polycrystalline silicon layer on a semiconductor substrate by sputtering is lithography or argon sputtering. Furthermore, in the above-mentioned method of forming a rough polycrystalline silicon layer above the semiconductor substrate, Iα = further includes the step of forming an amorphous silicon seed layer on the surface of the underlying polycrystalline silicon. Further, the method for forming a rough polycrystalline silicon layer above a semiconductor substrate further includes the following steps: forming a dielectric layer on the surface of the rough polycrystalline silicon layer; and forming an upper electrode plate on the surface of the dielectric layer. Polycrystalline silicon layer. The rough polycrystalline silicon layer, the polycrystalline silicon bottom layer, and the polycrystalline silicon layer used as the upper electrode plate are doped polysilicon layers doped with ions. Furthermore, according to the above object, the present invention provides another method for forming a thick chain polycrystalline spar layer on a semiconductor substrate, including at least the following steps: forming a polycrystalline silicon underlayer over the semiconductor substrate; using silicon or An argon sputtering method is used to process the above polycrystalline silicon bottom layer; a rough polycrystalline silicon layer is grown on the surface of the above polycrystalline silicon bottom layer. Furthermore, the above method of forming a rough polycrystalline silicon layer over a semiconductor substrate can also use a buffer oxidation etchant or dilute hydrofluoric acid to remove the primary oxide layer on the surface of the polycrystalline silicon substrate. EXAMPLES First Example 0725-7546TWF (N); 1-01-006; Jessica.ptd Page 6 531851 V. Description of the Invention (4) The following uses the flowchart shown in Figure 2 and Figures 5 to 7 A cross-sectional view of the process is shown to illustrate the first embodiment of the present invention. First, please refer to FIG. 5. Reference numeral 100 denotes a semiconductor substrate on which a semiconductor element such as a transistor has been formed (the figure is not shown for simplicity). Next, an insulating layer 110 made of, for example, borophosphosilicate glass (BPSG) is formed on the surface of the semiconductor substrate 100, and has an opening in contact with the semiconductor substrate 100.

Next, a polysilicon base 120 is formed on the surface of the insulating layer 110 by in-situ doped chemical vapor deposition (CVD). Then use buffered oxide etchant (BOE) or diluted HF solution to remove the native oxide naturally formed in the atmosphere. Furthermore, the surface of the above-mentioned polycrystalline silicon bottom layer 120 is treated with silicon or argon sputtering, for example, a silicon plasma 130 or an argon plasma is used to complete the sputtering step. The purpose of the sputtering step is to improve the subsequent rough compounding. The density of where silicon grows, and increase the adhesion of subsequent rough polycrystalline silicon layers.

Then, referring to FIG. 6, a high-quality rough polycrystalline silicon layer 4 is grown on the surface of the polycrystalline silicon underlayer 120 by chemical vapor deposition (temperature control is about 565 to 585 ° C). Of course, you can use the traditional method to first form an amorphous silicon film as a seed (see (i layer)) to promote the growth effect. After that, please refer to Figure 7 and use the traditional method for chemical mechanical Grinding method to remove the bottom layer of the polycrystalline silicon above the insulating layer 11 0, the rough polycrystalline silicon layer

0725-7546TWF (N); 1-01-006; Jessica.ptd p. 7 531851

V. Description of the invention (5) 140, the above-mentioned insulating layer 110 is removed, and a fin-shaped lower electrode 150 is formed at this time. Next, a dielectric layer 18 such as a dioxide button and a polycrystalline silicon doped with ions are deposited. Layer 17 0 to serve as the upper electrode. That is, this embodiment is characterized in that, as shown in the flowchart in FIG. 2, the polycrystalline silicon substrate is deposited—removing the native oxidation sound on the surface of the polycrystalline silicon substrate ~ The surface of the polycrystalline silicon substrate is sputtered with Shi Xi or argon— Deposition of rough polycrystalline stone layers. Second Embodiment The following is a description of a second embodiment of the present invention using the flowchart shown in FIG. 3 and the process cross-sectional views shown in FIGS. 5 to 7. &Quot; First, please refer to FIG. 5, the symbol 100 indicates a semiconductor substrate, which has been formed with semiconductor elements such as transistors (for simplicity, the figure is not shown). Second, 'for example, boron phosphorus is formed on the surface of the semiconductor substrate 100 An insulating layer 11 () composed of borophosphosilicate glass (BPSG), which has an opening in contact with the semiconductor substrate 100. Next, a chemical vapor deposition method using simultaneous in-situ doped ions (chemical vapor deposition; CVD) forms a bottom polysilicon base 120 on the surface of the insulating layer 110. Then, buffered oxide etchant (BOE) or dilute (j HF) dilute fluoric acid solution is used to remove A native oxide naturally formed in the atmosphere. Next, a mixed solution of ammonia and hydrogen peroxide (also known as SC1) using an oxidant and / or a mixed solution of hydrochloric acid and hydrogen peroxide (also It is called SC2) to remove impurities particles or organics on the surface of the polycrystalite layer 120, and because the above SCI or 疋 SC2 has the function of an oxidant, , The bottom layer of polysilicon can be

531851

A chemically oxidized thin layer is formed on the 120 surface (not shown). In addition, the surface of the chemically oxidized thin layer is treated with silicon or argon sputtering, for example, a silicon (Si) plasma 130 or an argon (Ar) plasma is used to complete the sputtering step. The purpose of the sputtering step is to improve subsequent roughening. The density of where the crystalline silicon grows and increase the adhesion of subsequent rough polycrystalline silicon layers. Then, referring to FIG. 6, a high-quality rough polycrystalline silicon layer 丨 4 〇 (temperature controlled at about 565 to 585 ° C) is grown on the surface of the polycrystalline silicon substrate 12 by a chemical vapor deposition method. Of course, an amorphous silicon film can be formed by using a conventional method as a seed layer to promote the growth effect. After that, please refer to FIG. 7, and perform chemical mechanical polishing (CMP) in a conventional manner to remove the polycrystalline silicon bottom layer 1 2 0 and the rough polycrystalline silicon layer 1 40 above the insulating layer 110, and then remove the above. The insulating layer 110 constitutes a fin-shaped lower electrode 150 at this time. Next, a dielectric layer 180 such as titanium dioxide or oxide / nitride / oxide is deposited, and a polycrystalline silicon layer 170 doped with ions is deposited. As the upper electrode. That is, this embodiment is characterized in that the flow chart shown in FIG. 3 'deposits the polycrystalline broken bottom layer—removing the primary oxide layer on the surface of the polycrystalline stone bottom layer ~ forming a chemical oxidation thin layer on the surface of the polycrystalline stone bottom layer A thin layer of chemical oxidation is deposited with Shi Xi or argon—deposits a rough polycrystalline silicon layer. Third Embodiment The third embodiment of the present invention will be described below using the flowchart shown in FIG. 4 and the process sectional views shown in FIGS. 5 to 7. First, please refer to FIG. 5. The symbol 100 indicates a semiconductor substrate, which has been

531851 V. Description of the invention (7) Semiconductor elements such as transistors are formed (not shown for simplicity). Next, an insulating layer 110 made of, for example, borophosphosilicate glass (BPSG) is formed on the surface of the semiconductor substrate 100, and has an opening in contact with the semiconductor substrate 100. Next, a bottom polysilicon layer 120 is formed on the surface of the insulating layer 110 by in-situ doped chemical vapor deposition (CVD). Furthermore, the surface of the above polycrystalline silicon layer is treated with silicon or argon sputtering. For example, a silicon plasma 130 or an argon plasma is used to complete the sputtering step. The purpose of the sputtering step is to improve the subsequent growth of the rough polycrystalline silicon. And increase the adhesion of the subsequent coarse-chain multicrystalline fragmentation. Then, referring to FIG. 6, a high-quality rough polycrystalline silicon layer 14 is grown on the surface of the polycrystalline silicon underlayer 120 by using a chemical vapor deposition method (the temperature is controlled at about 56.5 to 58.5 ° C). Of course, an amorphous silicon film can be formed by using a conventional method as a seed layer to promote the growth effect. After that, referring to FIG. 7, the conventional method of chemical mechanical polishing is used to remove the polycrystalline stone layer 120 and the coarse-chain polycrystalline stone layer 140 above the insulating layer 110, and then the insulating layer 110 is removed. A fin-shaped lower electrode 150 is formed at this time, and then a dielectric layer 180 such as a dioxide button and an ion-doped polycrystalline silicon layer 170 are deposited as an upper electrode. That is, this embodiment is characterized in that, as shown in the flowchart in FIG. 4, a polycrystalline stone layer is deposited—the surface of the polycrystalline stone layer with a stone or argon ore polycrystalline stone layer—a rough polycrystalline silicon layer is deposited. Therefore, No need to remove primary oxidation according to this embodiment

JJIOJl JJIOJl

Fifth, the description of the invention (8) steps, the effect of the process. The effect of the invention can not be simplified to the steps of oxidant treatment. One of the features of the present invention is to treat the bottom layer of the polycrystalline silicon, using a silicon plasma or an argon plasma to increase the surface of the subsequent bismuth a complex BB silicon substrate. Chemical oxygen

, Zu Furi E E silicon silicon layer adhesion. The growth position of tadpoles is improved according to the present invention. Again; elastic and easy to control adhesive force. This is enough to mention two rough polycrystalline silicon and polycrystalline again. According to the present invention, the pre-cleaning treatment is simplified to achieve simplification. Although the present invention has better defined the present invention, anyone who is familiar with this spirit and scope can make changes. The scope of the attached patent application may omit a series of private effects. The embodiments are disclosed as above, but the skilled artists will not deviate from the hair and retouching, so what is guaranteed by the present invention shall prevail. Sputtering place Thin layer Coarse wheel replication grain Standard of Shi Xi bottom layer Not used for precision protection 531851

, FIG. 2 and FIG. 2 are flowcharts of forming a coarse-chain polycrystalline spar layer on the surface of a semiconductor substrate according to the first embodiment of the present invention. , FIG. 3, and FIG. 3 are flowcharts of forming a coarse sugar polycrystalline spar layer on the surface of a semiconductor substrate according to a second embodiment of the present invention. Fig. 4 is a flow chart of forming a thick chain polycrystalline silicon layer on the surface of a semiconductor substrate according to a third embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a polycrystalline silicon underlayer formed on a surface of a semiconductor substrate according to an embodiment of the present invention. Fig. 6 is a schematic cross-sectional view of forming a rough slit polycrystalline silicon layer on the surface of the polycrystalline silicon bottom layer according to an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a polycrystalline silicon layer formed with an electric layer f as an upper electrode on the surface of a rough polycrystalline silicon layer according to an embodiment of the present invention. Explanation of symbols 100 ~ semiconductor substrate; 11〇 ~ insulating layer;

、 Polysilicon base day after day; 130 ~ silicon sputtering (silicon plasma ion); 140 ~ rough polycrystalline silicon layer; 15 ~ lower electrode; 1 80 ~ dielectric layer; 1 7 0 Tian as the doped polycrystalline silicon layer of the upper electrode.

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Claims (1)

531851 1. A method for forming a 2S... R ~ ^ Zusuo polycrystalline silicon layer over a semiconductor substrate includes at least the following steps: Ί forming a polycrystalline silicon underlayer over the semiconductor substrate; using an oxidizing agent on the polycrystalline silicon underlayer above Forming a chemical oxidation thin film · The sputtering method is used to process the chemical oxidation thin film; and q, a rough polycrystalline silicon layer is grown on the surface of the chemical oxidation thin layer. 2. The method of applying a square and rough polycrystalline silicon layer on a semiconductor substrate as described in item 1 of the scope of the patent application, wherein the oxidant is a mixed solution of ammonia and hydrogen. L3. The method of forming a rough, multicrystalline silicon layer on a semiconductor substrate as described in item 1 of the scope of the patent application, wherein the oxidizing agent is a mixed solution of hydrochloric acid and hydrogen. 4. The method for squarely forming a thick-slit polycrystalline silicon layer on a semiconductor substrate as described in item 1 of the scope of the patent application, wherein the surface of the bottom layer of the polycrystalline silicon is formed with a native oxide layer. 5. The method for forming a coarse-striped polycrystalline spar layer above a semiconductor substrate as described in item 4 of the scope of the patent application, wherein before the treatment with the oxidant, the buffer gasification residue or the nitrogen solution is used to remove it. Step of the above-mentioned native oxide layer. 6. The method for forming a thick-chain polycrystalline spar layer on a semiconductor substrate as described in item 1 of the scope of the patent application, wherein the above-mentioned low-plating method is based on; or splattered by chlorine. 7. The method of forming a thick chain polycrystalline spar layer on a semiconductor substrate as described in item 1 of the scope of patent application, which further includes the above-mentioned polycrystalline spar layer 〇725-7546TWF (N); 1-01-006; Jessica.ptd 531851 6. Scope of patent application Step of forming an amorphous silicon seed layer. 8. The method for forming a rough polycrystalline silicon layer on a semiconductor substrate as described in item 1 of the scope of the patent application, further comprising the following steps: forming a dielectric layer on the surface of the rough polycrystalline silicon layer; and forming a dielectric layer on the surface A polycrystalline silicon drawer is formed on the surface as an upper electrode plate. 9, 9 said above the semiconductor substrate as described in item 8 of the scope of patent application. A method for forming a rough polycrystalline silicon layer, wherein the rough polycrystalline silicon layer, the polycrystalline secondary layer, and the polycrystalline silicon layer serving as the upper electrode plate are ion-doped polycrystalline silicon layers. Y method 10. A method for forming a rough polycrystalline silicon layer over a semiconductor substrate includes at least the following steps: forming a polycrystalline silicon underlayer over the semiconductor substrate; processing the polycrystalline silicon underlayer by sputtering; A rough polycrystalline silicon layer grows on the surface of the underlying silicon layer. 11. The method for forming a rough polycrystalline silicon layer over a semiconductor substrate as described in item 10 of the scope of the patent application, wherein a primary oxide layer is formed on the surface of the above polycrystalline silicon bottom layer. / 12. The method for forming a rough polycrystalline silicon layer over a semiconductor substrate as described in item 1 of the scope of the patent application, before the above-mentioned sputtering method, the method further comprises removing the primary oxide layer by using a buffer oxidation etchant or a hydrofluoric acid solution. A step of. 13. The method for forming a rough polycrystalline silicon layer over a semiconductor substrate as described in item 10 of the scope of the patent application, wherein the above-mentioned sputtering method is silicon or argon sputtering. 〇725-7546TWF (N); 1-01-006; Jessica.ptd, page 14 531851 VI. Application scope of patent 14. As described in the patent application scope, the method for forming a rough polycrystalline silicon layer over a semiconductor substrate , Which further includes the step of forming > an amorphous silicon seed layer on the surface of the above polycrystalline silicon bottom layer. 15. The method for forming a rough polycrystalline stone layer on a semiconductor substrate as described in item 10 of the scope of the patent application, further comprising the following steps: forming a dielectric layer on the surface of the rough polycrystalline silicon layer; and A polycrystalline silicon layer is formed on the surface of the dielectric layer as an upper electrode plate. 16. A method for forming a rough polycrystalline silicon layer over a semiconductor substrate as described in item 15 of the scope of the patent application, wherein the rough polycrystalline silicon layer, the polycrystalline = bottom layer, and the polycrystalline silicon layer serving as an upper electrode plate A doped polycrystalline silicon layer 0725-7546TWF (N) * 1-01-006 * Jessica.ptd Page 15