TW591742B - Method for forming bottle trenches - Google Patents

Abstract

The method includes the steps of providing a substrate having a pad layer formed thereon, and a trench formed in a predetermined position; forming a masking layer at the bottom part of the trench; using liquid phase deposition (LPD) to form an LPD oxide layer on the sidewalls of the trench; removing the masking layer to expose the bottom part of the trench; subjecting the LPD oxide layer to annealing; and etching the bottom part of the trench not covered by the LPD oxide layer to form a bottle trench.

Description

591742 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a method for forming a bottle-shaped groove, and particularly to a method for forming an oxide layer on the bottle-shaped groove by using a liquid phase deposition method. In the process. [Prior technology] Generally speaking, a capacitor in a dynamic random access memory (DRAM) that is currently widely used is composed of two conductive layer surfaces (ie, electrode plates) with an insulating material interposed therebetween. The capacitor The ability to store charge is determined by the thickness of the insulating material, the surface area of the electrode plate, and the electrical properties of the insulating material. With the recent progress in semiconductor process design, the size of semiconductor elements has been reduced to increase the density. The base area of memory cells in the memory must be continuously reduced to enable integrated circuits to increase their density. At the same time, the electrode plate portion of the memory cell capacitor must have sufficient surface area to store sufficient charge. However, in the case of continuous miniaturization, the trench storage node capacitance in the dynamic random access memory also decreases. Therefore, it is necessary to find ways to increase the storage capacitance to maintain the good operating performance of the memory. . Methods that have been widely used to increase the storage capacitance of DRAMs include, for example, increasing the width of the bottom of the trench, thereby increasing the surface area to form a bottle-shaped capacitor. The above method involves forming a trench on a semiconductor beautiful board, and forming an 'annular oxygen oxide' on the upper half of the trench by oxidation, and then depositing a nitride layer and a polycrystalline silicon layer to cover the sidewall and bottom of the trench:

0548-8890TWf (Nl); 91082; phoebe.ptd Page 5 591742 V. Description of the invention (2) Next, the polycrystalline silicon is then removed from the mask, the polycrystalline layer, and removed. Then move half. Finally, the above steps are performed on the bottle shape of the upper part with the semiconductor, regardless of the layer of oxide layer, the upper part is removed from the ring groove. The body size is becoming more and more simplified in the process and a shielding layer is filled in the lower half of the trench. , Forming a nitride layer. The oxide layer at the bottom of the trench and the upper half of the polycrystalline silicon layer are sequentially oxidized to form a protective layer covering the upper and lower half of the trench for wet etching to form a diameter larger than this. Under the premise, it is difficult to open a fine groove, and the above-mentioned process is complicated, and it is necessary to sink the kf multiple times or in time, which is not economical, because of the method of forming a bottle groove with high productivity. [Summary of the Invention]

In view of this, this 本 明明 古 | Q transformation, and in line with economic efficiency to provide-a kind of manufacturing steps simple n day Xiao Xi 2 method of forming grooves. Another object of the present invention is a method for receiving a bottle-shaped groove, which can be supplied at 0%. 9 types, formed by liquid deposition

In the manufacturing process, I1 is in a DRAM or a finer line width DRAM, and there is no need to form multiple material layers as is conventional. In order to achieve the above object, the present invention provides one, the steps of which include: providing a method for forming a right-shaped bottle-shaped groove ^. / ', Opening ^ a layered structure and a groove-like abundant conductive substrate, A masking layer is formed under the trench, θ,, a — / ¾ ^ / u wl ^ ° 卩, and a liquid-phase deposition method is used to form a liquid-phase deposition oxide layer on the sidewall of the trench. Exposing the trench The lower half of the trench; the liquid phase deposits oxygen; ^ == masking layer and the bottom half of the trench, which is not the liquid phase 2 j2, forms a bottle-shaped trench with a conductive substrate. Semi-emulsified layer

591742

According to the present invention, a protective layer is formed to form a protective layer under the groove and the protective layer covers the liquid deposition layer. The oxide layer coverage according to the present invention is not only simplified, but the formation is also reduced to make this obvious. It is easy to understand, and the detailed description is as follows: Example, and annealing of the trench and the trench phase deposition shielding layer; engraving the bottom of the trench to form a bottle-shaped complex energy lift and other embodiments to form a trench to remove the trench One bottle type groove heterogeneity, and the purpose, and the other has a cushion structure layer on the half structure; on the liquid, the oxide layer is removed to carry out the layer 'and the low semiconductor system provided by the semiconductor The above-mentioned article of the program-controlled conductor device invention specifically mentions the side wall of the semiconductor substrate of the preferred bottle-shaped trench; forming an unshaped trench that forms a liquid phase out of the trench and is not part of the liquid phase half. The method of the tank, and the method of liquid phase deposition to improve the process quality, characteristics, and the methods shown in the drawings include: forming a masking layer to deposit the lower half of the oxide; the rate of the oxide layer deposited and oxidizing the liquid deposition process step. Detailed description [Embodiment] The second embodiment of Example 1 shows the bottle-shaped groove formation 2 of the first embodiment of the present invention. On the other hand, Ai X, X, X, and U are referred to as U and the trench 130, in which the layer 110 and the nitride layer 120. 〒 塾 layer ,,,. The structure includes emulsification. Then, a masking layer 140 is formed in the trench by half-etching to form the ancient sound μ, +, and cattle P as shown in FIG. 1B. The bottle-shaped trench formed subsequently is also formed. Height is the interval between soil and soil. The above shielding layer is preferably a photoresist 591742

material. , 郴 = ,, / Liquid phase deposition method (Liquid Phase DeP0sition) > forming a liquid phase deposition oxide layer 150 to cover the sidewall of the trench 130, as shown in Figure ic f, the preferred thickness of the night phase deposition oxide layer It is 1 〇 ~ 丨 〇〇〇〇angstrom, this Π i ί Ϊ J3 two angstrom. The above-mentioned reaction in which an oxide layer is formed by a liquid phase deposition method can be performed early and can be performed at low temperature (usually below 500c). The solution used is hexadecanoic acid, and the chemical reaction formula is as follows: Consumption H2SiF6 + 2H2〇 ^ H3B〇3 + 4HF When the above reaction formula I is HF in a reaction test solution—Si02 + 6HF… Reaction formula I BF4_ + H30 + + 2H20… Reaction formula II Chemical equilibrium reaction formula, when the reaction chamber II 'Reaction formula I goes to the right.

When the oxide layer is formed by the liquid-phase deposition method described above, the photoresist material and the nitrided layer have selective properties, that is, the liquid-phase deposited oxide layer does not grow on the shielding layer and the nitrided layer 120. Therefore, as shown in FIG. 1C, the liquid-phase-deposited oxide layer 140 formed by the liquid-phase deposition method is formed only on the sidewall of the trench 130 and does not form the f on the shielding layer 14 or the nitride layer 12. The masking layer 14 is then removed by, for example, an inorganic test solution such as sulfuric acid or with a dry ozone gas, as shown in FIG. 1D. Then, the liquid-phase deposition oxide layer 150 is annealed to cause the liquid-phase deposition oxide layer to be bifurcated, so as to improve the selectivity of the test solution for silicon etching to the liquid-phase deposition oxide layer, so as to facilitate the subsequent formation of bottle-shaped trenches. Carved steps. ▲ Finally, the semiconductor substrate in the lower half of the trench is removed by wet etching, that is, the portion not covered by the liquid-phase deposition oxide layer is formed as shown in FIG.

0548-8890TWf (Nl); 91082; phoebe.ptd Page 8 Bi / 42 V. Description of the invention (5) Implementation of t; Figure 2-2E is a cross-sectional view showing the manufacturing process of the method for forming a bottle-shaped ditch Zen according to Embodiment 2 of the present invention. The formation of the humiliation groove is shown in FIG. 2A, and a semiconductor substrate 100 is provided. The upper layer structure and the grooves 1 3 0, 1 are used to perform a “layer” and a nitride layer 120. / 、 中The ytterbium layer structure includes oxidized sound, f Ϊ: forming a protective layer 12 5 ′, preferably a dielectric material such as yttrium oxide. The surface φ of the above-mentioned nitrided layer 120 and the rime formation along the side of the trench 13〇 The thickness of the protective layer is preferably between 50 and 100 angstroms. For soil, a shielding layer 14 is formed in the lower half of the trench to return to the height as shown in Fig. 10B. The height of the temporary shielding layer above the surface of the trench is defined as the degree of return of the bottle trench formed later, and its material is preferably a photoresist material.

Phasffe 'is the same as in Example 1 and a liquid-phase deposition method (Liq is called escort # i ^ 〇Slt10n) is used to form a liquid-phase-deposited oxide layer 15 to cover the above-mentioned 2C ^ " 0 0 0 Angstrom, this The thickness of the embodiment is 300 angstroms. When the oxide layer is formed by the liquid-phase deposition method, the photoresist material is selected. A ft # is that the oxide layer will not grow on the shielding layer 140, but will grow on the material protection layer 125. Therefore, the liquid phase = subtracted layer 14G formed by liquid phase deposition only forms on the protective layer, as shown in Figure 2G. Or, the shielding layer 140 is removed, as shown in FIG. 2d, which can be achieved by, for example,

0548-8890TWf (Nl); 91〇82; ph〇ebe.ptd

Page 9 V. Description of the Invention 1. An inorganic test solution, such as sulfuric acid or dry ozone, is used to deposit the oxide layer 150 for annealing to remove the above body. Then, the test solution for liquid-phase etched silicon is used to densify the liquid-phase deposition oxidized emulsion layer to improve the etch of the etched groove Side wall of the lower half. The above θ-coated protective layer 1 2 5 and methods such as diluting argon fluoride (DHF) or slowly removing the protective layer can be used at the end of the example. The etched square =? Acid is not an oxide layer deposited in the liquid phase. Covering the Shixi substrate 'is also the bottle-shaped groove 160. The test solution shown in FIG. 2E is formed by the above-mentioned etching / knife. In addition, non-roses can also be used, such as NH4OH, ΝΝ03, etc. According to the present invention 3: directional dry #etching. The process of forming a bottle-shaped groove, and the method of shaking the mold groove can greatly shorten the conventional semiconductor manufacturing process. Although the present invention has been limited to the present invention by private individuals, any ^ 1 ^ example is disclosed as above, but it is not used for r ^ & since then, the artist does not depart from the scope of the present invention When this can be done, the scope of the spirit should be regarded as the attached application; and Retouching 'Therefore, the protection of the present invention is defined as the target of shame.

591742 Brief description of the drawings Figures 1A to 1E are cross-sectional views showing the manufacturing process of the method for forming a bottle-shaped groove in Embodiment 1 of the present invention. Figures 2A to 2E are cross-sectional views showing the steps of a method for forming a bottle-shaped groove according to Embodiment 2 of the present invention. [Symbol Description] 100 ~ semiconductor substrate; 110 ~ oxide layer; 120 ~ nitride layer; 130 ~ trench; k 1 25 ~ protective layer; 140 ~ shielding layer; 150 ~ liquid Phase deposition of oxide layer; 160 to bottle-shaped groove.

0548-8890TWf (Nl); 91082; phoebe.ptd p. 11

Claims (1)

Scope of Six Applications 1. A method for forming a bottle-shaped trench, provided with a cushion structure and a trench-like pattern 2: comprising: forming a semiconductor substrate with a shielding layer under the trench 5; forming by a liquid deposition method 41; on the wall; 41. an oxide layer is removed on the side of the trench to remove the shielding layer to expose the trench to anneal the liquid-phase deposited oxide layer; =, to etch the lower half of the trench, and the conductor The substrate forms a bottle-shaped groove. The half covered by the liquid-phase deposition oxide layer. As in the first patent application, the shielding layer is photoresist. 31. Method for forming a bottle-shaped groove 3, 31. As in the first patent application, where the liquid-phase deposition oxide layer is thick; ^ Method for forming a bottle-shaped groove, where the last name is engraved. Shell; II: Shaped ^ ^ directional drying out. The method of forming the amp-shaped groove as described in item 1 of the patent scope, wherein the pad structure includes an oxide layer and a nitride layer. :-A method for forming a bottle-shaped trench, the steps include: providing a semiconductor substrate having a pad structure and a trench; forming a compliance layer on the trench structure and a sidewall of the trench; forming a The masking layer is in the lower half of the trench; a liquid phase deposition method is used to form a liquid phase deposition oxide layer on the protective layer; 1 page 12 0548-8890TW f (Nl); 91082; phoebe .ptd 591742 VI. Application Patent scope " — removing the shielding layer to expose the lower half of the trench; annealing the liquid-phase deposition oxide layer; removing a protective layer not covered by the liquid-phase deposition oxide layer; and etching the trench The lower half of the semiconductor substrate not covered by the liquid-phase deposition oxide layer forms a bottle-shaped trench. 7. The method for forming a bottle-shaped groove according to item 6 of the scope of the patent application, wherein the compliance layer is a dielectric material. 8. The method for forming a bottle-shaped trench as described in item 7 of the scope of the patent application, wherein the dielectric material is an oxide layer. 9 · The method for forming a bottle-shaped groove as described in item 7 of the scope of patent application, wherein the shielding layer is a photoresist. I 0 · The method for forming a bottle-shaped groove as described in item 7 of the scope of the patent application, wherein the thickness of the liquid-phase deposited oxide layer is 10 to 100 Angstroms. II. The method for forming a bottle-shaped groove as described in item 7 of the scope of the patent application, wherein the last etching step is performed by wet etching with NH4OH, HN03 or anisotropic dry etching. 1 2 · The method for forming a bottle-shaped groove according to item 7 of the scope of the patent application, wherein the cushion structure includes an oxide layer and a nitride layer. 1 3 · The method for forming a bottle groove as described in item 7 of the scope of patent application, wherein the removal of the protective layer is performed by one of bHF or Dhf.