Patent SG-11201907133X-A (SG)
Title: Die encapsulation in oxide bonded wafer stack
Inventor: DRAB JOHN J
IPC: H01L23/10
Filed: 2017-11-16
Abstract: jjrzygraiii 11411111111111111111 , 411 11 112 112 FIG. 2A 210 \" - - I W4 1W e ji l i r l- , ' WM 224N, 208 .. 208 M r . . .. E N . IP RIM 206 11.11111 - 111101111 ii - 1.• 212 214 216 218 202 204 200 „ . ./2c0 W O 20 18/ 2127 85 Al PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) Iiiimmolimmuminiolomolownionommill (10) International Publication Number WO 2018/212785 Al WIPO I PCT (12) INTERNATIONAL APPLICATION (19) World Intellectual Property Organization International Bureau (43) International Publication Date 22 November 2018 (22.11.2018) FIG. 3D (51) International Patent Classification: H01L 25/065 (2006.01) HOlL 21/50 (2006.01) H01L 21/98 (2006.01) H01L 21/54 (2006.01) H01L 23/10 (2006.01) (21) International Application Number: PCT/US2017/061922 (22) International Filing Date: 16 November 2017 (16.11.2017) (25) Filing Language: English (26) Publication Language: English (30) Priority Data: 15/596,663 16 May 2017 (16.05.2017) US (71) Applicant: RAYTHEON COMPANY [US/US]; 870 Winter Street, Waltham, Massachusetts 02451-1449 (US). (72) Inventors: DRAB, John J.; c/o Raytheon Company, 870 Winter Street, Waltham, Massachusetts 02451-1449 (US). MILNE, Jason G.; c/o Raytheon Company, 870 Winter Street, Waltham, Massachusetts 02451-1449 (US). (74) Agent: MARAIA, Joseph M. et al.; Burns & Levinson LLP, 125 Summer Street, Boston, Massachusetts 02110 (US). (81) Designated States (unless otherwise indicated, for every kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IR, IS, JO, JP, KE, KG, KH, KN, KP, KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, (54) Title: DIE ENCAPSULATION IN OXIDE BONDED WAFER STACK (57) : Structures and methods of fabricating semicon- ductor wafer assemblies (100) that encapsulate at least one die (108, 202, 402) in a cavity (110, 204, 404) etched into an oxide bonded semiconductor wafer stack (102+104, 206+208, 406+408). The methods generally include the steps of position- ing the die (108, 202, 402) in the cavity (110, 204, 404), me- chanically and electrically mounting the die (108, 202, 402) to the wafer stack (102+104, 206+208, 406+408), and encapsulat- ing the die (108, 202, 402) within the cavity (110, 204, 404) by bonding a lid wafer (106, 210, 410) to the wafer stack (102+104, 206+208, 406+408) in one of multiple ways. Semiconductor pro- cessing steps are applied to construct the assemblies (e.g., deposi- tion, annealing, chemical and mechanical polishing, etching, etc.) and connecting the die (e.g., bump bonding, wire interconnecting, ultrasonic bonding, oxide bonding, etc.) according to the embod- 224 iments described above. The cavity (110, 404) may be hermeti- cally sealed to encapsulate the semiconductor die (108, 402). The wafer assembly (100) may be diced to produce one or more semi- conductor chips, each semiconductor chip including one or more encapsulated semiconductor die (108, 202, 402). A thermal inter- face (164, 170, 412) may be comprised between the semiconduc- tor die (108, 402) and one or more of the wafers (102, 104, 106, 406, 408, 410). The wafer stack (102+104, 406+408) and the lid 222 wafer (106, 410) may be oxide bonded together. Alternatively, the wafer stack (206+208) and the lid wafer (210) may be bump (214) bonded so as to define an air gap (224) providing thermal isolation from the cavity (204). One of the wafers (102, 104, 106) may define a conduit (168) to the cavity (110) from the exterior of the wafer assembly (100), [Continued on next page] WO 2018/212785 Al MIDEDIMOMMIDIREIDIHIHOHOMMODEVON SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (84) Designated States (unless otherwise indicated, for every kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, KM, ML, MR, NE, SN, TD, TG). Published: — with international search report (Art. 21(3)) wherein the conduit (168) and the cavity (110) are at least partially filled with a thermally conductive material, are evacuated and sealed providing a vacuum package or are evacuated and backfilled with a liquid or gas before sealing.