Patent SG-11201808546Y-A (SG)
Title: Process and apparatus for processing a nitride structure without silica deposition
Inventor: BASSETT DEREK
IPC: H01L21/3213
Filed: 2017-03-24
Abstract: INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property -, Organization IIIMI41101110101011111 HO 11111011101011111111 1011 1011 00 11111111111 0111111 International Bureau ... .1 j ..... ...... (10) International Publication Number (43) International Publication Date WO 2017/172533 Al 5 October 2017 (05.10.2017) IN I PO I P CT (51) (21) (22) (25) Filing Language: (26) Publication Language: (30) (71) (71) International Patent Classification: (72) Inventors: BASSETT, Derek; 1403 White Elm Cove, Ce- H01L 21/306 (2006.01) HO1L 21/67 (2006.01) dar Park, Texas 78613 (US). PRINTZ, Wallace P.; 8933 H01L 21/3213 (2006.01) H01L 21/02 (2006.01) Lanna Bluff Loop, Austin, Texas 78749 (US). ROTOND- International Application Number: ARO, Antonio L.P.; 12828 Texas Sage Ct., Austin, Texas 78732 (US). MINAMI, Teruomi; 27-9-903 Harakoga-ma- PCT/US2017/024128 chi, Kurume city, Fukuoka 830-0046 (JP). FURUKAWA, International Filing Date: Takahiro; 845-11 Umemitsu-machi, Kurume-city, 24 March 2017 (24.03.2017) Fukuoka (JP). English (74) Agent: MADRIAGA, Manuel, B.; Tokyo Electron U.S. Holdings, Inc., 2400 Grove Boulevard, Austin, Texas English 78741 (US). Priority Data: (81) Designated States (unless otherwise indicated, for every 62/315,559 30 March 2016 (30.03.2016) US kind of national protection available): AE, AG, AL, AM, 62/315,632 30 March 2016 (30.03.2016) US AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, 15/467,939 23 March 2017 (23.03.2017) US BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, 15/467,973 23 March 2017 (23.03.2017) US DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, Applicant: TOKYO ELECTRON LIMITED [JP/JP]; HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KH, KN, Akasaka Biz Tower, 3-1 Akasaka 5-chome, Minato-ku, KP, KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, Tokyo 107-6325 (JP). MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, Applicant (for JP only): TOKYO ELECTRON U.S. RU, RW, SA, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, HOLDINGS, INC. [US/US]; 2400 Grove Boulevard, Aus- TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, tin, Texas 78741 (US). ZA, ZM, ZW. [Continued on next page] = (54) Title: 302 , \,. 304-- \ 306 \ 308-. --- 310 , , PROCESS AND APPARATUS FOR PROCESSING A NITRIDE STRUCTURE WITHOUT SILICA DEPOSITION (57) : Techniques are provided to remove the growth of colloidal X300 silica deposits on surfaces of high aspect ratio structures during silicon ni- tride etch steps. A high selectivity overetch step is used to remove the de- posited colloidal silica. The disclosed techniques include the use of phos - phoric acid to remove silicon nitride from structures having silicon nitride formed in narrow gap or trench structures having high aspect ratios in which formation of colloidal silica deposits on a surface of the narrow gap or trench through a hydrolysis reaction occurs. A second etch step is used in which the hydrolysis reaction which formed the colloidal silica deposits is reversible, and with the now lower concentration of silica in the nearby phosphoric acid due to the depletion of the silicon nitride, the equilibrium drives the reaction in the reverse direction, dissolving the de- posited silica back into solution. = = = PROVIDING A SUBSTRATE HAVING A HIGH ASPECT RATIO STRUCTURE COMPRISED OF A FIRST SET OF EXPOSED FEATURES COMPRISING SILICON NITRIDE, AND A SECOND SET OF EXPOSED FEATURES COMPRISING SILICON OR SILICON OXIDE = - - = LOADING THE SUBSTRATE INTO A WET CHEMICAL PROCESSING SYSTEM = = = PERFORMING A FIRST ETCH STEP COMPRISED OF EXPOSING THE SUBSTRATE TO A FIRST WET ETCH CHEMICAL COMPOSITION TO REMOVE AT LEAST PART OF THE SILICON NITRIDE FROM THE HIGH ASPECT RATIO STRUCTURE = = THE EXPOSING THE SUBSTRATE TO A FIRST WET ETCH CHEMICAL COMPOSITION FORMING SILICA DEPOSITS ON THE SILICON OR SILICON OXIDE OF THE HIGH ASPECT RATIO STRUCTURE = = 11 M M kr) N IN 1-1 --...„ IN 1-1 0 N PERFORMING A SECOND ETCH STEP COMPRISED OF EXPOSING THE SUBSTRATE TO A SECOND WET ETCH CHEMICAL COMPOSITION TO REMOVE AT LEAST SOME OF THE SILICA DEPOSITS FORMED ON THE SILICON OR SILICON OXIDE DURING THE FIRST ETCH STEP FIG. 3 O WO 2017/172533 Al MIDEDIM11110111111111111111111111111111111111111111111111110111111111111111111111 (84) Designated States (unless otherwise indicated, for every SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, kind of regional protection available): ARIPO (BW, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, GH, SZ, GN, GQ, GW, KM, ML, MR, NE, SN, TD, TG). TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, RU, KZ, Published: TJ, TM), European (AL, AT, BE, BG, CH, CY, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, CZ, IT, RS, DE, — LT, SE, with international search report (Art. 21(3))