Chế tạo cảm biến áp suất và gia tốc thu nhỏ bằng công nghệ ăn mòn ion hoạt hóa

Nshien ciru, Phdt trien va Uhg duns Cong nshe Vdt lieu (KC.02/06-10)- Ha Wgi 27/11/2009 CHE TAO CAM BIEN AP SUAT VA GL\ TOC THU NHO BANG CONG NGHE A N M O N I-ON HOAT HOA Vu Ngoc Hung Le Van Minh , Nguyen Van Minh \ Trinh Quang Thong ^ Vien dao tao Quoc te vk Khoa hoc Vat lieu (TITMS), Vien Vat ly Ky thuat flEP), Dai hoc Bach khoa Ha Noi (HUT), So Dai Co Viet Hai Ba Trung Ha Noi Viet Nam Email: hungvungoc®itims.edu.vn thongtq@nims.edu.vn l 1 : Tom tit Bai bdo trinh bay cdc ket qua nghien ciru thiet vd che tao cam bien dp sudt va gia toe dp dien trd thu nhd sir dung phiin loai SOI (silicon-on-insulator) Ldp d-xn d giira ciia phien SOI duoc diing di dure hien ky thuat dn mdn dimg nhdm dai duoc ad day cdc cdu tnic mdng va beam cd dp chinh xdc cao qua trinh an mdn di hudng tir pha hoi Cdc cam bien duoc che tao theo cong nghe vi co khdi dp dung ky thuat an mdn i-dn hoat hda sau (DRIE) Cdu tnic dien gdm cdc dien trd duoc tao bang ky thuat khuich tdn sir dung dung dich pha tap SOD Kich thudc ngoai ciia cd hai loai cam biin chi vao khoang 2x2 mm vd lxl mm Dp day mdng va dam la 10 urn, Cdc cam bien dd the hien cdc dac tnmg dien hinh nhu dp nhay, khd nang dap ung nhu mong muon 2 I GIOT THIEU Tren phuong dien lich sir cam bien ap suat va gia toe ap dien tro la cac linh kien dien hinh duoc che tao bang cong nghe v i co khoi [1] U u diem noi bat ciia cac l i n h kien la gia re duoc che tao hang loat kich thudc nho dd nhay cao va on dinh ve mat co hoc Cac cam bien da duoc ung dung rong rai nhieu linh vuc nhu cong nghiep to[2], san xuat dien gia dung, va cac thiet bi y sinh (do huyet ap va ddng chay) [3 ] Dac biet la nhu cau ve cac cam bien kich thudc sieu nho cho cac ung dung linh vuc y te D d la ly ciia viec day manh cac nghien c i m m d i cho muc dich Cam bien ap dien ttd sih'c la cac bo chuyen doi cac bien dang co hoc cac t i c dong ciia ap suat hoac gia toe tin hieu dien V i the, cau tnic chung ciia l i n h kien ludn co phan dien bao gom cac ap dien trd tich hop loai p va phan co la cac v i cau tnic nhay co kieu mang hoac dam Phan cau tnic co co the dugc che tao bang k y thuat an mdn udt hoac an mon kho Trong nghien cuu phien de silfc kieu SOI, (silicon-on-insulator) co mot ldp oxit silfc kep gitra kdp silfc da dugc sir dung de tao mang hoac dam cd day chinh xac Cac ket qua nghien cuu ve thiet ke va dac trung l o i ciia cam bien se duoc trinh bay bai bao H THIET KE VA CHE TAO Doi vdi cam bien ap dien trd nguoi ta thudng sir dung bdn dien ttd ket noi vdi theo cau hinh cau dien ttd Wheatston nhu duoc chi tren h i n h Thdng thudng cac dien ttd se dugc dat tai nhirng khu vuc ma ung suat vat lieu cd gia tri ldn nhat Trong nghien cuu cac dien ttd cd k i c h thudc rdng 30 p m va dai p m Su thay ddi tin hieu l d i thay ddi dien ttd suat dudi tac dons ciia nsoai luc (ap suat hoac eia tdc) duoc xac dinh nhu sau: - source D K Trong dd Vsource la dien ap nguon nudi Do dugc chd tao bang phien S O I gdm mot ldp oxit silfc kep giua hai ldp sih'c, mot dav 10 u m va mot day 450 p m nen mang va dam nhay co ciia cam bien cd dd day tuong i m g la 10 u m V d i muc dich thu nhd kich thudc cac lan luot la l x l m m " va 2x2 mm" 254 cam bien duoc che tao cd k i c h thudc ngoai Nshien cim Phdt triin yd tine dune Cone nehe Vdt lieu (KC.02/06-10)- Ha Noi 27/11/2009 xtfag*- scire* Ra R Hinh Cdu hinh cdu dien trd Wheatston Mechanically sensitive beam Silicon thin diaphragm Suspension beam Supporter Rigid frame I Interconnections (a) (b) Hinh Cdu true cam bien dp sudt (a)va gia tdc (b) dp dien trd Cau true cua hai loai cam bien duoc chi tren hinh Cam bien ap suat co mot mang mong nhay ap suat va mot cau dien trd Wheatston Trong k h i do, cam bien gia tdc cd bdn dam nhay co song song v d i cac canh cua k h d i gia v d i ba cau dien trd Wheatston tich hop trdn dd Q u i trinh che tao hai loai cam bien da duoc xay dung g d m budc, sir dung M A S K quang hoc cho cam bien ap suat va 10 budc, sir dung M A S K quang hoc cho cam bien gia tdc (hinh 3va4) Phien duoc sir dung dd che tao cam bidn la phien SOI, dudng kinh 4-inch loai n Phan dien duoc che tao trudc d phia ldp silfc day 10 p m , cau tnic co duoc thuc hidn che tao sau tir phia ldp silic day Dau tien, mot ldp oxit silfc {S1O2) mdng duoc tao bang phuong phap dxy hda khd m d i trudng thdi k h i dxy va hydro Cac ap dien t r d duoc che tao bang phuong phap khudch tan sir dung dung dich khuech tan boron (SOD) D d sau khudch tan xac dinh dd day dien trd duoc dieu chinh bang thdi gian khudch tan v d i tri sd bang 1/10 dd rdng dien trd Trong qua trinh che tao, nhdm (aluminum - A l ) duoc phii ldn be mat phidn hoac de tao dudng dan hoac ddng vai trd vay lieu bao ve cho qui trinh an mdn khd bang cong nghe phun xa 255 Nshien ciru, Phdt trien vd Uhg dung Cons nghe Vdt lieu (KC.02/06-10)- Ha Ndi 27/11/2009 (sputtering technology) Q u i trinh quang khac duoc thuc hien tren may quang khac mat (double-side aligner) P E M 800 sudt qua trinh che tao Cau tnic co duoc che tao bang cong nghe an m o n kho tren thidt b i RTE-lOiP cua hang S A M C O (Nhat Ban) Dac diem noi bat cua thidt b i la viec su dung cudn day kieu xoay trdn dc (Tornado coil) de tao plasma tang cudng (Inductively couple plasma - I C P ) "' " U ' = t ' — t I — iSi mm Buried Si0 w tan i ' * cza Si0 t lLi)"" , f l | r=3 Boron doping layer Hinh Sa qui trinh che tao cam bien dp sudt: 7-dxy hda phien, 2-Md cua sd tao dien trd, 3-Phii dung dich pha tap Bo, 4-Md cira so de tao tiep xiic vdi dien trd, 5- Phu nhdm lam day ddn cho mach,, 6-md cira so de an mdn tao mdng nhay dp sudt, 7-An mdn tao cdu true, 8- tay bd kdp oxit silic S1O2 a giira cua phien SOI He an mdn su dung hdn hop SF6/C4F8 cho qui trinh an mdn kho sau (cd ten goi la qui trinh Bosch) [ ] Q u i trinh dua tren plasma cam ung ket hop de tao cac gdc t u tach tir C4F8 Cd hai budc cong nghe tuan hoan lap lai tao mot chu trinh la an m d n (etch) va lang dong (deposition) Trong trudng hop nay, SF6 la k h i dung dd an mdn de B u d c lang dong la dd tao mot l d p polymer nham hinh l d p bao vd vach cua cau true an m o n Day la qua trinh dang hudng, nen l d p polymer be mat se lap tuc duoc tay bd b d i qua trinh ban pha i-dn kieu phun xa va lam Id bd mat si-lic phia d u d i cho qua trinh an mdn tiep theo Q day, budc lang dong duoc dat giay, budc an mdn la giay K h i l d p o x i t giua phien ddng vai trd cho qua trinh an mdn dirng dam bao day ciia mang nhay ap suat hoac dam nhay co ciia cac cam bien D o vay, sau an mdn cd the dat hang tram microns v d i vach hoc an mdn hau n h u thang dung va v d i tdc an mdn cao hon 3-4 lan so v d i k y thuat an mdn udt Phien sau k h i da hoan thien cac cong doan che tao can thiet se duoc cat nhd cac cam bidn rieng le (chip) Cac chip cam bidn sau se duoc han ndi day (nhdm) v d cam bien bang ky thuat han det (wedge bonding) sir dung thiet b i West Bond 256 Nshien cim, Phdt triin yd Ung duns Cong nshe Vdt lieu (KC.02/06-10)£3 Ha Noi 27/11/2009 a 10 t as t M IS t t rmSi n Si02 ^ A l •• Buried Si0 rz=3 Boron doping layer Hinh So che tao cam bien gia toe: 7-oxy hoa phien, 2-Md cira so tao dien tro, 3-Phii dung dich pha tap Bo, 4-Mo cira so de tao tiep xiic voi dien tro, 5-Pphit nhom lam day ddn cho mach, 6-Mo cira so de dn mdn tao khe dao dong cho khdi gia trong, 7-Dinh dang tao dam, 8-Phii nhdm de lam vdt lieu che chan bdo ve cho qua trinh dn mdn khd sau tao cdu true khdi gia vd cdc dam nhay co, 9- An mdn khd sau tao cdu tnic, 10-tdy bd kdp oxit silfc SiC>2 d giifa cua phien SOI III CAC DAC TRUNG THUC NGHIEM Cac cam bien sau k h i dugc che tao da dugc thu nghiem cac dac trung l o i dien hinh Cac he dac trung l o i cua cam bien deu ket noi may tinh de thu nhan, x u ly d u lieu va hien thi ket qua He cam bien ap suat su dung bo cung cap ap suat chuan M C I 0 va von ke hien so da nang Keithley-2000 de chi thi the l o i M o t cac ket qua ciia cam bien dugc chi tren hinh cho ca hai loai cam bien k i c h thuoc 2x2 m m va l x l m m Do nhay tuong ung cua hai loai cam bien la 2.5 m V / V k P a va 0,186 mV/V.kPa The l o i the hien dap ung lap lai rat tot va on dinh thoi gian dai Dong thoi dap tuyen cam bien bieu hien ro dai ap suat tir den 100 kPa The offset la gia tri the tuong ung mot dien ap l o i vao co djnh k h i chua co ap suat tac dong The co tri so ~ m V va phu thuoc nhiet N h i n chung, ket qua khao sat cho thay, the offset giam manh k h i nhiet tang (tir nhiet phong - 300 K len 330 K , k h i do, nhay khong b i anh huong dang ke dai nhiet He cam bien gia toe sir dung mot bo rung chuan (Mitutoyo MEE-45) va mot thiet bi khuech dai tin hieu (Mitutoyo A M E -100) truoc k h i dua vao von ke da nang hien so Keithley2000 de chi thi the l o i Cam bien gia toe dugc nghien cuu che tao day cho phep co the xac dinh gia toe theo phuong (3 bac t u - D O F ) M o t nhirng ket qua dugc trinh bay tren hinh 2 257 Nshien ciru, Phdt trien vd Uhg dung Cons nshe Vdt lieu (KC.02/06-10)- Hd Ndi 27/11/2009 120 - • Sensor dimension of lxl mm* & Sensor dimension of 2x2 mm" 100 Input voltage of 1.5 V „ S£ ca | > g a | 80 60 40 20 20 40 60 80 Pressure fkPa) 100 Hinh Ddc trung the loi phu thudc dp sudt ciia cam bien dp sudt 700 m (tin * mm if umm +$n*.*, + '- r,fcôCtJ*!*ti#ô if t*ô*ô* y it* 600 ã 'i u iằi M* fkô v " A** 0*'