TW565907B - Manufacturing method of dielectric layers - Google Patents

Abstract

A manufacturing method of dielectric layers includes putting a substrate into a furnace and forming a silicon oxide layer on the substrate; performing an anneal process for transforming silicon oxide layer into silicon oxy-nitride layer; forming a silicon nitride layer on the silicon oxy-nitride layer; and forming a silicon oxide on the silicon nitride layer. Then silicon oxy-nitride layer/silicon nitride/silicon oxide stacked dielectric layers are formed on the substrate. The silicon oxy-nitride layer/silicon nitride/silicon oxide stacked dielectric layers are formed in the same furnace, so the process steps are reduced.

Description

565907

Modification ^ The present invention relates to a method for manufacturing a dielectric s applied to a semiconductor device, and more particularly to a method for manufacturing a capacitor dielectric layer. When the integration degree of the entire semiconductor device is getting higher and higher, in the era of Dynamic Random Access Memory (DRAM), the area of the cell is also becoming smaller and smaller. Therefore, how to increase the stored charge of the capacitor in the memory cell under a limited area has become an important issue. Content. . Generally speaking, methods to increase the capacity of a capacitor to store charge include increasing the capacitance, reducing the thickness of the dielectric layer of the capacitor, and the number of dielectric materials. However, increasing the area of the 穑 隹 谇 η + '· and Ding% order of the thunder packet will make the dram J product degree (I ntegrat 1 ο η) decrease; decrease, 丨 68 is based on the average level of the dielectric layer and The stability of Kao Danguang's thickness is still unable to be properly applied. Therefore, the method of forming the electrical layer is currently the direction of the current commonly used charge storage capacitors with a high dielectric constant charge capacity; II: The direction of development. Stacked layers made of silicon, for example, oxidized particles /-the electrical layer is made of emulsified silicon and nitride (Si / 0 / N), silicon nitride / silicon oxide (N〇), siliconized silicon (0N) stacked dielectric layered Silicon / silicon oxide / silicon nitride (NON) stack Nie Bayi dielectric layer (Sl / N / 0), nitrogen for silicon oxide / silicon nitride (0N) $ 1, layer (Si / N / 0 / N) . The oxide layer of the stacked dielectric layer (Si / N / 〇) layer is grown under normal pressure. As for the dielectric layer, the silicon oxide / silicon nitride (〇N) stacked dielectric layer is To reduce its effective dielectric thickness, the maximum amount of stored charge. As a result, the oxide layer will seriously affect the capacitor layer (Si / 0 / N) has been replaced by the nitride dielectric / oxide / nitride (0N) stacked dielectric structure. 〇)

9727twfl.ptc 565907

For the nitride nitride / silicon nitride (N) due to the selection of silicon / silicon nitride / 11 and "% ^ 〇1 / N / 〇), the interface defect Λ plane ΛΓ of the fossil evening: Shi Xi The interface is poor, that is, Shi Xi / Ni will produce more than hit fj :, the interface defect density is high, so in view of this, the method of the present invention can be used to seed f in a single furnace tube. Manufacture / Silicon Nitride / Silicon Oxide π 11 Fabrication of Silicon Nitride Silicon with Dielectric Constant / It is a chemical layer (si / Sion / n / o), so the manufacturing process is sufficient Another purpose of Ming is to propose an effective dielectric constant that increases the dielectric film layer. M: method, which can increase the number of charges that can be stored, and increase the capacity of the capacitor: early area capacity: in view of: 'The present invention provides: The substrate is placed in the furnace tube, and then the same step: ': method' will be used to form-a layer of silicon oxide layer on the substrate, and the following steps are performed in order to form a silicon oxide layer into a silicon oxynitride layer. . Then ^ 谩 into the tempering process to form a silicon layer. In the silicon nitride layer: = silicon oxide layer is formed on the substrate to form oxynitride / nitridation. . / ^ 21 oxide broken layer of the present invention for forming silicon oxynitride / nitride stack of dielectric layers ". SiON / N / O) of the fabrication process based at Pro propriety of silicon stacked dielectric layers n Sltu) of the formed

565907 Case No. 91125106 Amendment V. Description of the Invention (3) That is, different gases are introduced into the same reactor tube at different times to carry out different reactions. There is no need to follow the reaction as usual. The reaction furnace tube is changed differently, so the process can be simplified. Furthermore, a thin silicon oxide layer is formed under a low pressure, and then nitrous oxide is used as a reaction gas, and then an oxidation process is performed and then a tempering process is performed to form a silicon nitride oxide layer. The quality of the interface between the silicon oxynitride layer and silicon formed by the above method is better than that of forming the silicon oxynitride directly on silicon, so the dielectric layer formed by the method of the present invention has better quality. In addition, when nitrous oxide is used as a reaction gas and the tempering process is performed after the oxidation process, by replacing the Si-0 bond with Si-N bonds, not only the quality of the silicon oxide layer can be enhanced, but also the rate of electron trapping and Silicon oxide defects. Therefore, the reliability of the oxynitride layer can be increased. In addition, using nitrous oxide as a reaction gas to perform the re-oxidation process of the silicon nitride layer, in addition to reducing the number of unfinished bonds in the silicon nitride layer, and filling the pins that may be generated in the nitride layer Pins (P inh ο 1 es) (that is, the defects of the silicon nitride layer can be reduced), so that the capacitor may prevent leakage and increase the breakdown voltage, making the capacitor suitable for high voltage operation. Moreover, the silicon oxynitride / silicon nitride / oxygen silicon stacked dielectric layer manufactured by the manufacturing method of the dielectric layer of the present invention can be used as the dielectric layer and trench type of stacked capacitors. ) The dielectric layer of the capacitor, and the poly-crystalline silicon inter-layer dielectric layer (Inter-Poly Dielectric Layer) between the control gate and the floating gate of the flash memory. In order to make the above and other objects, features, And advantages can be more obvious and easy to understand, the following exemplifies preferred embodiments, and cooperates with the accompanying drawings to make details

9727twfl.pt c Page 7 565907 _Case No. 91125106_Year_Month_5. Description of the invention (4) The description is as follows: 10 0 Substrate 10 2 Lower electrode layer 10 4 Silicon oxide layer 10 6 Nitrogen oxide Silicon layer 10 8 Silicon nitride layer 11 0 Silicon oxide layer 11 2 Example of the upper electrode layer The present invention is a method for manufacturing a dielectric layer, and a capacitor is used as an example for illustration. 1A to 1D are flowcharts of a method for manufacturing a capacitor according to a preferred embodiment of the present invention. Please refer to FIG. 1A to provide a substrate 100, such as a silicon substrate, and the manufacture of some semiconductor components on the substrate 100 has been completed, for example, the manufacture of a metal-oxide semiconductor (not shown) has been completed. . Next, an electrode layer 102 under the capacitor is formed on the substrate 100. The material of the lower electrode layer 102 is, for example, polycrystalline silicon, and a method for forming the lower electrode layer 102 is, for example, a chemical vapor deposition method, or a part of silicon-based single crystal silicon is used as the lower electrode. After the lower electrode layer 102 is formed, the surface of the lower electrode layer 102 will react with the surrounding oxygen in an oxygen-containing environment. This oxidation reaction will occur at room temperature, thus forming a thin layer of dioxide. Silicon is called the native oxide layer. Therefore, before the next process, a cleaning process is usually performed to remove the native oxide layer. This cleaning process uses, for example, hydrofluoric acid as a cleaning solution.

9727twfl.ptc Page 8 565907 _Case No. 91125106_Year_Month__ V. Description of the invention (5) Then, put the substrate 100 into the low pressure chemical vapor deposition furnace tube (L 0 W Pressure Chemical Vapor Deposition Furnace) A stone oxide layer 104 is formed on the lower electrode layer 102. The method for forming the oxidized stone layer 104, for example, uses oxygen as a process gas, and passes it into a low-pressure chemical vapor deposition furnace tube to perform a reaction. The reaction pressure is, for example, 0.5 Torr (Torr), and the reaction temperature is, for example, At about 900 ° C, oxygen is reacted with polycrystalline silicon (silicon) to form a silicon oxide layer 104 having a thickness of, for example, 15 angstroms. Next, referring to FIG. 1B, the tempering process is performed after the oxidation process. In the same low-pressure chemical vapor deposition furnace tube, nitrous oxide (N20) is used as the process gas for the reaction. The reaction pressure is, for example, 0.5 Torr (T ◦ rr), and the reaction temperature is, for example, 9 0 ° C. Right and left, the nitrous oxide is reacted with the silicon oxide layer 104 to form a silicon oxynitride layer 106. Nitrogen-Rich Layer is formed near the silicon / silicon dioxide interface by replacing the Si-0 bond with the Si-N bond during the tempering process after the oxidation process with a nitrous oxide gas. Not only can enhance the quality of the silicon oxide layer, but also reduce the rate of electron sinking and silicon oxide defect points. Therefore, the reliability of the silicon oxynitride layer 106 can be increased. Next, referring to FIG. 1C, a silicon nitride layer 108 is formed on the silicon oxynitride layer 106. The formation method of the silicon nitride layer 108 is, for example, two gas silane (SiH2Cl2) and ammonia gas (NH3) as a process gas, which is passed into a low-pressure chemical vapor deposition furnace tube for reaction, and the reaction pressure is, for example, 0. 25 Torr (Torr), the reaction temperature is, for example, about 700 ° C, dichlorosilane (Si H2C12) and ammonia (N H.0) are reacted to form a thickness on the silicon oxynitride layer 106 For example, it is a nitride layer with a thickness of 35 angstroms 108. Please refer to Figure 1D, and perform the reoxidation process of the silicon nitride layer 108 without changing the low-pressure chemical vapor deposition furnace tube. Nitrous (N20)

9727twfl.ptc Page 9 565907 _ Case No. 91125106 _ year month day__ 5. Description of the invention (6) is a process gas for the reaction, the reaction pressure is, for example, 0.5 Torr (T 〇rr), the reaction temperature is, for example, At about 900 ° C., the nitrous oxide is reacted with the nitrided oxide layer 108 to form a layer of oxided oxide layer 110. In the re-oxidation process of the I fossil layer 108, in addition to reducing the number of unfinished bonds in the silicon nitride layer 108, and can fill pinholes that may occur in the silicon nitride layer 108 ( P inh ο 1 es) (reducing the defects of the nitride nitride layer), so it can prevent the leakage of the capacitor and increase the breakdown voltage, making the capacitor suitable for high voltage operation. After that, a capacitor electrode layer 1 1 2 is formed on the silicon oxide layer 110. The material of the upper electrode layer 1 12 is, for example, polycrystalline stone, and a method for forming the same is, for example, a chemical vapor deposition method. It can be known from the above-mentioned preferred embodiments of the present invention that the present invention is based on the field (I n) in the process of forming a silicon oxynitride / silicon nitride / silicon oxide stacked dielectric layer (S i / S i Ο N / N / 0). S it U) method, that is, different gases are passed into the same reaction furnace tube at different times to carry out different reactions. There is no need to replace the reaction furnace tube with the different reactions as is common practice. Therefore, the process can be simplified. In addition, a thin layer of oxidized stone is formed under low pressure, and then a nitrous oxide is used as a reaction gas, and then an oxidation process is performed to form a silicon nitride oxide layer. The quality of the interface between the silicon oxynitride layer and silicon formed by the above method is better than that of directly forming silicon oxynitride on silicon. Therefore, the dielectric layer formed by the method of the present invention has better quality. In addition, when nitrous oxide is used as a reaction gas and the tempering process is performed after the oxidation process, by replacing the Si-0 bond with Si-N bonds, not only the quality of the silicon oxide layer can be enhanced, but also the rate of electron trapping and Silicon oxide defects.

9727twfl.ptc Page 10 565907 _Case No. 91125106_ Year Month Day _ ^ V. Description of the invention (7) Therefore, the reliability of the oxynitride layer can be increased. In addition, using nitrous oxide as the reaction gas to perform the re-oxidation process of the silicon nitride layer, in addition to reducing the number of unfinished bonds in the silicon nitride layer, and filling the pins that may be generated in the silicon nitride layer Pins (P inh ο 1 es) (reducing defects in the silicon nitride layer), so it can prevent the capacitor from leaking and increase the breakdown voltage, making the capacitor suitable for high voltage operation. In the embodiment of the present invention, the formation of a capacitor dielectric layer is taken as an example for description. Of course, the silicon oxynitride / silicon nitride / silicon oxide stacked dielectric layer manufactured by the manufacturing method of the dielectric layer of the present invention can also be used. As the dielectric layer of stacked capacitors, the dielectric layer of trench capacitors, and the polycrystalline silicon interlayer dielectric layer between the control gate and floating gate of flash memory (I nter-Ρ ο 1 y Dielectric Layer). Although the present invention is disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. The scope of protection shall be determined by the scope of the attached patent application.

9727twfl.ptc Page 11 565907

9727twil.pic Page 12

Claims (1)

565907 _ Case No. 91125106_year month__ VI. Patent Application Scope 1. A method for manufacturing a dielectric layer, the method includes: providing a substrate; placing the substrate in a furnace tube; inside the furnace tube; A oxide layer is formed on the substrate; in the furnace tube, the tempering process includes passing nitrous oxide into the furnace tube, so that the nitrous oxide reacts with the oxidized fragment layer to form a nitrous oxide layer Forming a silicon nitride layer on the silicon oxynitride layer in the furnace tube; and forming a stone oxide layer on the nitrided layer in the furnace tube; 2. The manufacturing method of the dielectric layer according to item 1 of the scope of the patent application, wherein the step of forming the silicon oxide layer on the substrate in the furnace tube includes passing an oxygen gas into the furnace tube to make the oxygen gas The chip reaction with the substrate forms the silicon oxide layer. 3. The method for manufacturing a dielectric layer according to item 1 of the scope of the patent application, wherein the step of forming the silicon nitride layer on the silicon oxynitride layer in the furnace tube includes combining a two-gas silane and an ammonia gas. Pass into the furnace tube, and react the dichlorosilane and the ammonia gas to form the silicon nitride layer. 4. The method for manufacturing a dielectric layer according to item 1 of the scope of patent application, wherein the step of forming the silicon oxide layer on the silicon nitride layer in the furnace tube includes passing nitrous oxide into the furnace tube. , Reacting the hafnium oxide with the silicon nitride layer to form the hafnium fossil layer. 5. A method for manufacturing a capacitor dielectric layer is applicable to a substrate. The substrate has been formed with an electrode layer, and the method includes: 9727twfl.ptc Page 13 565907 _Case No. 91125106_Year_Month__ Sixth, the scope of the patent application is to place the substrate that has formed the lower electrode layer in a furnace tube; in the furnace tube, on the lower electrode layer Forming a silicon oxide layer; performing a tempering process in the furnace tube includes passing nitrous oxide into the furnace tube, and reacting the nitrous oxide with the silicon oxide layer to form a silicon nitride oxide layer; in the furnace tube Forming a silicon nitride layer on the silicon oxynitride layer; and forming a silicon oxide layer on the silicon nitride layer in the furnace tube. 6. The method for manufacturing a capacitor dielectric layer according to item 5 of the scope of patent application, wherein the material of the lower electrode layer includes polycrystalline silicon. 7. The method for manufacturing a capacitor dielectric layer according to item 6 of the scope of the patent application, wherein the step of forming the silicon oxide layer on the substrate in the furnace tube includes passing an oxygen gas into the furnace tube to make the Oxygen reacts with the silicon of the lower electrode layer to form the silicon oxide layer. 8. The method for manufacturing a capacitor dielectric layer as described in item 5 of the scope of the patent application, wherein the step of forming the silicon nitride layer on the silicon oxynitride layer in the furnace tube includes dichlorosilane and ammonia. Gas is passed into the furnace tube, and the dichlorosilane and the ammonia gas are reacted to form the silicon nitride layer. 9. The method for manufacturing a capacitor dielectric layer according to item 5 of the scope of patent application, wherein the step of forming the silicon oxide layer on the silicon nitride layer in the furnace tube includes passing nitrous oxide into the furnace tube In the process, the ytterbium oxide is reacted with the silicon nitride layer to form the silicon oxide layer. 10. The method for manufacturing a capacitor dielectric layer according to item 5 of the patent application scope, wherein the furnace tube comprises a low-pressure chemical vapor deposition furnace tube. 97271 wt'l. Pt c page 14 565907 _ case number 91125106_ year month__ VI. Patent application scope 1 1. A method of manufacturing a dielectric layer, the method includes: providing a substrate; placing the substrate on A furnace tube; a first gas is passed into the furnace tube to form a first dielectric layer on the substrate; a second gas is passed into the furnace tube and a tempering process is performed so that the first A dielectric layer becomes a second dielectric layer; a third gas is passed into the furnace tube to form a third dielectric layer on the second dielectric layer; and a A fourth gas to form a fourth dielectric layer on the third dielectric layer. 1 2. The method for manufacturing a dielectric layer according to item 11 of the patent application, wherein the first gas includes oxygen. 1 3. The method for manufacturing a dielectric layer according to item 11 of the patent application, wherein the second gas includes nitrous oxide. 14. The method for manufacturing a dielectric layer according to item 11 of the scope of patent application, wherein the third gas includes dichlorosilane and ammonia gas. 1 5. The method for manufacturing a dielectric layer according to item 11 of the patent application, wherein the fourth gas includes nitrous oxide. 16. The method for manufacturing a dielectric layer according to item 11 of the scope of patent application, wherein the first dielectric layer includes a silicon oxide layer. 17. The method for manufacturing a dielectric layer according to item 11 of the scope of patent application, wherein the second dielectric layer includes a silicon oxynitride layer. 1 8. The manufacturer of the dielectric layer as described in item 11 of the scope of patent application 9727twfl.ptc Page 15 565907 9727twfl.pt c p. 16