US 20150279654A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2015/0279654 A1 KATO et al. (43) Pub. Date: Oct. 1, 2015 (54) TREATING SOLUTION FOR ELECTRONIC The invention is embodied by a treating solution for elec PARTS, AND PROCESS FOR PRODUCING tronic parts that is an aqueous Solution containing one or two ELECTRONIC PARTS or more of anionic Surface active agents represented by the following formulae (1), (2) and (3), and a process for produc (71) Applicant: FINE POLYMERS CORPORATION, ing an electronic part. Tokyo (JP) (72) Inventors: Toshitada KATO, Noda-city (JP); (1) Naoya SATO, Noda-city (JP); Shigeru KAMON, Noda-city (JP): Koichiro a-y OGATA, Noda-city (JP) (73) Assignee: FINE POLYMERS CORPORATION, OC Tokyo (JP) (21) Appl. No.: 14/670,785 wherein R. R. and R stands for hydrogen or an alkyl or alkylene group having 1 to 4 carbon atoms, and X (22) Filed: Mar. 27, 2015 stands for a functional group capable of becoming an anionic ion. (30) Foreign Application Priority Data Mar. 29, 2014 (JP) ................................. 2014-07O641 (2) Publication Classification R4 ;: (51) Int. Cl. * N HOIL 21/02 (2006.01) 4NeX CILD II/00 (2006.01) X2 pi CID I/02 (2006.01) CID 3/04 (2006.01) HOIL 2/3 II (2006.01) wherein R stands for hydrogen or an alkyl or alkylene C09K 3/08 (2006.01) group having 1 to 4 carbon atoms, X stands for a func (52) U.S. Cl. tional group capable of becoming an anionic ion, and in CPC ...... H0IL 21/0206 (2013.01): HOIL 21/31 III stands for a natural number of greater than 2. (2013.01); C09K 13/08 (2013.01): CIIDI/02 (2013.01): CI ID3/042 (2013.01): CIID II/0047 (2013.01) (3) (57) ABSTRACT The invention provides an aqueous solution capable of selec tively protecting a nitrogen-containing silicon compound COA4 ex from corrosion by a treating Solution for etching, cleaning or X4 X the like, etching oxygen-containing, carbon-containing sili con in particular, and making a large etch rate difference wherein Rs stands for hydrogen or an alkyl or alkylene between a nitrogen-containing silicon compound and an oxy group having 1 to 4 carbon atoms, and X, and X stands gen-containing silicon compound, and a process for produc for a functional group capable of becoming an anionic ing electronic parts as well. ion. US 2015/0279.654 A1 Oct. 1, 2015 TREATING SOLUTION FOR ELECTRONIC trench formed in it. With this resist pattern as a mask, the PARTS, AND PROCESS FOR PRODUCING insulating film and protective film are etched to form an ELECTRONIC PARTS opening through which the upper Surface of the silicon Sub strate is exposed. Note here that the resist pattern will be FIELD OF THE INVENTION removed by asking or the like after the formation of the opening. Then, the protecting film is used as a mask for 0001. The present invention relates to a treating solution etching of the silicon substrate thereby forming a device for electronic parts that makes it possible to remove silicon isolation trench. oxide or the like in a process of producing electronic parts 0006 Further, the silicon nitride film structure is also Such as semiconductors and display devices, and selectively adopted for a pixel-driving thin-film transistor (TFT) or the protect nitrogen-containing silicon compounds in an etching like in a display device Such as a liquid crystal device. For step, and a process for producing an electronic part using this instance, the ohmic contact layer of a channel portion of the treating Solution as well. thin-film transistor is dry etched, after which a passivation layer in a silicon nitride film form is locally provided. BACKGROUND ART 0007 Thus, the silicon nitride film is increasingly used for 0002. In order to form Large scale integration circuit various electronic devices. One of the reasons is the fact that (LSIs), and thin-film transistors (TFTs) for liquid crystal such silicon nitride films differ from mask materials com displays on glass Substrates, there has been technology well posed mainly of silicon Such as silicon oxide and oxygen in established in which a photoresist is used to form the neces terms of anticorrosion capability. This capability makes Sure sary device structure or circuit structure pattern that is in turn a silicon nitride layer is used as a stopper layer for dry etching, etched in an etching step for removal of unnecessary portions a corrosion preventive layer, a mask or the like in the produc thereby obtaining the desired device structure or circuit struc tion of semiconductor devices. The silicon nitride film may be ture used in combination with a low-dielectric-constant insulating 0003. The device structure or circuit structure to beformed material of the silicon oxide type represented by Low-kmate may have a variety of configurations depending on the desired rial or the like and containing oxygen and other elements such electronic device. In recent years, however, a variety of struc as fluorine and carbon for patterning or acquiring selective tures using silicon nitride film materials have also been under etching capability when they are used as a mask. study. Typically in the process for producing non-volatile 0008. However, a problem with such etching or cleaning memory devices like flash memory devices, a gate insulating steps is that when the etching solution and cleaning Solution film pattern and a gate electrode pattern are formed on a used corrode the aforesaid compounds, the silicon film con semiconductor Substrate. These electrode structures gener taining nitrogen is also more or less corroded. In particular, ally comprise an electrode material that is made conductive recent microstructures of devices are likely to be subject to by incorporating a dopant in polysilicon and an insulating noticeable adverse influences even from a slight corrosion; So film formed of SiO, SiN or SiON. When the electrode struc there is mounting demand for the development of more ture further includes a floating gate and a control gate, there is advanced corrosion preventive technology. an insulating layer formed of ONO (oxide-nitride-oxide), 0009 Translation of PCT Application No. 2004-528716 SiON or SiN so as to insulate them. To this end there is a step goes deep into adverse influences of etch selectivity on Such provided in which the semiconductor substrate is etched materials as silicon oxides in the step of wet etching materials across the gate electrode pattern to form a trench. containing silicon and nitrogen Such as silicon nitride and 0004 For a DRAM memory cell structure too, the struc silicon oxynitride. However, what is considered there is a ture of a silicon nitride film is adopted. Typically in a stack problem with the etching of such a material as silicon oxide at type memory cell, a device isolation area is formed on a the time of etching a material containing silicon and nitrogen, P-type silicon Substrate to form a gate oxide film and a gate and that publication says or suggests nothing about the electrode. Then, a Source? drain area is formed, and an insu reverse phenomenon whatsoever. In addition, the aforesaid lating film is furtherformed by CVD or the like, with a contact problem is only solved by performing etching in a dilute provided on it. Then, there is a polycrystalline silicon film aqueous Solution containing hydrofluoric acid (HF) in a con formed for electric conductivity, which film is in turn pat centration range of 0.001M to 0.1Mata temperature of 25°C. terned to form a lower electrode of a capacitor. Then, a thin to 90°C. In other words, the temperature and concentration of silicon nitride film is formed by CVD all over the surface to the aqueous solution of hydrofluoric acid are nothing else provide the capacitor with an upper electrode. Then, a BPSG than defined. For this reason, any study of prevention of film (insulating film) is formed by CVD, and a contact for corrosions by the introduction of other compound elements is connection to a bit line for data retrieval is opened using not made at all. known photolithographic/etching technology. Finally, an electric conductive film and a BPSG (insulating film) are PRIOR ART formed to obtain a stack type DRAM memory cell. Patent Publication 0005. The silicon nitride film is also used for the formation of a photodiode proximity structure of a conventional CCD (0010 Patent Publication 1 Translation of PCT Applica imaging device including a device isolation mechanism hav tion No. 2004-528716 ing an STI structure. Specifically, a silicon Substrate is pro vided on it with an insulating film comprising a silicon oxide SUMMARY OF THE INVENTION film, and the insulating film is provided on it with a protective film comprising a silicon nitride film or the like. This protec Objects of the Invention tive film is provided on it with a resist pattern having an 0011. The present invention has for its objects to provide opening or aperture in the area having the device isolation an aqueous solution capable of (1) selectively protecting a US 2015/0279.654 A1 Oct. 1, 2015 nitrogen-containing silicon compound from corrosions 4 The treating solution for electronic parts as recited in any caused by chemicals used for various treatments such as one of 1 to 3, wherein said hydrofluoric acid is obtained by etching and cleaning while, at the same time, (2) etching dissolution of a water-soluble fluoride salt. silicon in general, and oxygen-containing, carbon-containing silicon in particular, and (3) making a large difference in etch 5The treating solution for electronic parts as recited in any rate between a nitrogen-containing silicon compound and an one of 1 to 4, which contains a cyclic compound having an oxygen-containing silicon compound, and a process for pro occupied area Smaller than a naphthalene ring.