Maitiro ekugadzira machipisi eRAM emapiritsi
RAM (Random Access Memory) chimwe chezvinhu zvakakosha mutablet. Pasina RAM, tablet haigone kumhanyisa maapplication zvakanaka, kuchinjana pakati pemabasa nekukurumidza, kana kuchengetedza mhinduro kana maitiro akawanda ari kushanda panguva imwe chete. Pasinei nehukuru hwayo hudiki uye yakavharirwa zvakasimba mukati memudziyo, machipisi eRAM anokonzerwa nemaitiro akaomarara, akanyatsojeka ekugadzira anosanganisira mazana ematanho. Chinyorwa chino chinotaura nezvematanho makuru ekugadzira machipisi eRAM anowanzo shandiswa mumapiritsi—kazhinji rudzi rweLPDDR (Low Power Double Data Rate), sezvo akagadzirwa kuti ashandise simba shoma.
1. Dhizaini yezvivakwa uye zvirevo
Maitiro acho anotanga kare chip chaiyo isati yakwana. Mapoka ekugadzira kumakambani e semiconductor anoona zvinodiwa nemusika we tablet: kugona kwayo (semuenzaniso, 4GB, 8GB, 12GB), bandwidth, kushandiswa kwesimba, uye kuenderana ne system-on-chip (SoC). Kune mapiritsi emazuva ano, RAM inofanira kuyera mashandiro uye kushanda zvakanaka kwebhatiri. Saka, zviyero zvakaita seLPDDR4X kana LPDDR5/LPDDR5X zvinowanzoshandiswa.
Muchikamu chekugadzira, mainjiniya vanogadzirawo magadzirirwo emasero ekurangarira, mabhangi ekurangarira, nzira dzedata (mabhazi edata), uye macircuit anotsigira akadai sema amplifiers ekunzwisisa, ma decoder emutsara/koramu, uye ma refresh mechanisms. DRAM yakasiyana neSRAM: DRAM inochengeta ma bits ichishandisa ma capacitor madiki anofanira kudzokororwa nguva nenguva, nepo SRAM ichikurumidza asi inodhura zvakanyanya uye inoda nzvimbo yakawanda.
2. Kugadzira uye kusimbisa marongerwo enzvimbo
Kana magadzirirwo acho anyatsotsanangurwa, dhizaini yacho inoshandurwa kuita marongerwo chaiwo: mepu yakadzama yenzvimbo dzema transistors, ma capacitor, ma metal interconnects, uye ma layers anofanira kugadzirwa pa silicon wafer. Danho iri rinoda software ye EDA (Electronic Design Automation) uye maitiro ekusimbisa akaomarara kuti ive nechokwadi chekuti dhizaini yacho inogadzirwa uye inoita sezvakarongwa.
Kusimbiswa kunosanganisira kutevedzera nguva, kushandiswa kwesimba, kusimba kwekuchinja-chinja kwemaitiro, uye kuyedzwa kwepfungwa kudzivirira zvikanganiso zvinouraya zvinogona kukonzera kuti wafer batch yese isashande.
3. Kugadzira mawafer esilicon (substrates)
Machipisi eRAM anogadzirwa pamawafer esilicon akachena zvakanyanya. Silicon inogadzirwa kubva kumaingots ekristaro akarimwa achishandisa nzira yakafanana neyaCzochralski. Maingots acho anochekwa kuita mawafer matete, opukutwa kusvika panzvimbo yakati sandara zvakakwana, uye ocheneswa nemakemikari.
Hunhu hwewafer hunosarudza goho (huwandu hwemachipisi akabudirira). Mukugadzira semiconductor, kunyangwe zvidimbu zveguruva zvisingaonekwe zvinogona kukonzera zvikanganiso padie imwe chete (chip imwe chete) kana kunyange nzvimbo yakakura yewafer.
4. Maitiro ekumberi: kuumbwa kwematransistors nemasero ekurangarira
Danho rinotevera nderekuvaka zvikamu zvemagetsi pawafer kuburikidza nematanho akasiyana-siyana. Iyi ndiyo pfungwa ye "fab" ye semiconductor.
a. Kuokisijeni uye kuiswa kwechikamu chidiki
Wafer iyi yakafukidzwa nezvinhu zvakatetepa zvakaita sesilicon dioxide, silicon nitride, kana imwe dielectric. Rutivi urwu runogona kushanda seinsulator, shield, kana sechikamu che transistor/capacitor structure.
b. Kudhirowa kwemifananidzo (kudhirowa kwemifananidzo)
Photolithography inzira yeku "dhirowa" pateni yedunhu. Wafer inoputirwa ne photoresist (chinhu chinonzwa chiedza) uye yozovhenekerwa nemasiki uchishandisa muchina we lithography. Dzimwe nzvimbo dzinooma kana kunyunguduka (zvichienderana nerudzi rwe resist), zvichigadzira pateni. Maitiro aya anodzokororwa kakawanda padanho rega rega.
Muma node ekugadzira emazuva ano, lithography inogona kushandisa Deep Ultraviolet (DUV) kana Extreme Ultraviolet (EUV) kugadzira zvinhu zvidiki zvikuru. Kana zvinhu zvidiki, masero ekurangarira anogona kurongedzwa, kugona kunowedzera, uye kushandiswa kwesimba kunogona kuderedzwa—kunyange zvazvo kuomarara kwemaitiro kuchikwira.
c. Kucheka
Kana patani yacho yagadzirwa, zvinhu zviri munzvimbo dzakati zvinobviswa kuburikidza ne dry etching (plasma) kana wet etching (makemikari) kuti pave nechimiro chinodiwa.
d. Kuisa doping uye kuiswa kwemaion
Kuti transistor ishande, nzvimbo dzesilicon dzinofanira "kuiswa doped" - tsvina yakaita seboron kana phosphorus inowedzerwa kuti igadzire nzvimbo dzep-type ne n-type. Izvi zvinoitwa nekuisa maion zvinoteverwa ne annealing (kudziyisa) maitiro ekuchenesa kristaro uye kuita kuti ma dopants ashande.
e. Kugadzirwa kwema capacitor eDRAM
Chinhu chikuru cheDRAM i capacitor yekuchengetera chaji. Nekuti ma capacitor anofanira kunge akakura zvakakwana kuti achengetedze chaji inoverengwa, asi nzvimbo yechip yakaganhurirwa, magadzirirwo e capacitor anogadzirwa mumhando nhatu (3D), dzakadai se trench kana stacked capacitors, zvichienderana netekinoroji. High-k dielectric zvinhu zvinowanzo shandiswa kuwedzera capacitance pasina kuwedzera saizi yemuviri.
Sero reDRAM rinowanzova ne transistor imwe chete ne capacitor imwe chete (1T1C). Hunhu hwechimiro ichi hunosarudza kugadzikana, kumhanya, uye zvinodiwa pakuzorodza.
5. Maitiro ekumashure: simbi dzakasungirirwa uye kubatana kwadzo
Kana ma transistors ne memory cells zvagadzirwa, chip inoda "mugwagwa mukuru" wekutakura masaini nemagetsi. Izvi zvinoitwa kuburikidza ne back-end-of-line process (BEOL): kuunganidzwa kwezvikamu zvakawanda zvesimbi zvinobatana.
Chigadzirwa chesimbi chinowanzova mhangura ine chipingamupinyi chekupararira kwemhangura kudzivirira mhangura kuti isakuvadze mamwe machira. Chigadziko chinodzivirira kupisa (dielectric) chinoiswa pakati pesimbi kuderedza simba rezvipembenene uye kubuda kwezviratidzo. Mumachipisi emazuva ano, huwandu hwemachira esimbi hunogona kuva hwakakura, imwe neimwe iine pateni yakasiyana yekubatanidza mamiriyoni kune mabhiriyoni ezvinhu.
6. Kuongorora, metrology uye kudzora mhando padanho rega rega
Mukati mekuita uku, mawafer anoongororwa nguva dzose achishandisa maturusi emetrology: maelektron microscopes, kuyerwa kweukobvu hwefirimu, kuyedzwa kwezvikanganiso, uye kuongorora pamusoro pemapatani (kururama kwematanho ari pakati pezvikamu). Nekuti wafer imwe chete ine mazana kusvika kuzviuru zvemadhai, zvikanganiso zvidiki zvinogona kukanganisa zvikuru mitengo.
Mafekitori ema semiconductor anochengetedza dzimba dzakachena dzine mitemo yakasimba, sezvo zvidimbu zvidiki-diki zvinogona kukanganisa kugadzirwa. Vashandi vanopfeka mbatya dzakagadzirwa, uye mhepo inoyerera inodzorwa kuderedza kusvibiswa.
7. Kuongororwa kwewafer: kuyedzwa kwekutanga padanho rewafer
Mushure mekunge machira ese apera, wafer haisati yachekwa. Danho rinotevera rinonzi wafer probing kana kuti wafer sorting. Needles dzeprobe dzinobata ma test pads padhiyi yega yega kuti dzitarise mashandiro ekutanga: kana masero ekurangarira anogona kunyorerwa uye kuverengwa kubva, kana paine nzvimbo dzisina kunaka, uye hunhu hwemagetsi hwakadai sekubuda kwemvura uye kushandiswa kwesimba.
Mhedzisiro yacho inorongwa (wafer mepu) kuti ione madhayi akanaka neasina kunaka. Panguva ino, kambani inoongororawo goho uye inogadzirisa maitiro acho kana mamwe mapatani ekusakwana akaonekwa.
8. Kucheka-cheka: kucheka wafer kuita madhayi
Mawafer akaedzwa anochekwa kuita machipisi madiki (dies) uchishandisa dhayamondi kana laser. Mawafer asina kunaka anowanzo rasirwa. Awo anopasa bvunzo anobva aenderera mberi nechikamu chekurongedza.
9. Kurongedza: kushandura die kuita chip yakagadzirira kushandiswa
Kurongedza hakusi kungo "putira" chete; kunoita kuti chip ikwanise kubatanidzwa nebhodhi redunhu, kuchengetedzwa, uye kukwanisa kubvisa kupisa.
Pa tablet RAM, pakingi inonyanya kushandiswa iBGA (Ball Grid Array) kana kuti imwe mhando diki yakaita seFBGA, kazhinji ine configuration yakakodzera LPDDR. Padanho rino, die inosungirirwa ku substrate, yakabatana uchishandisa waya bonding kana flip-chip, uye mabhora ekusolder anowedzerwa kuti aibatanidze ku motherboard.
Nekuti mapiritsi matete, saizi nekukwirira kwepakeji yemachipisi zvakakosha. Vagadziri vanosarudza mapakeji madiki asi achichengetedza masaini akasimba, tichifunga kuti RAM inoshanda nekukurumidza uye inonzwa kukanganiswa.
10. Kuedza kwekupedzisira, kupatsanura, uye kubatanidzwa patablet
Machipisi akaputirwa anoedzwazve mukuyedzwa kwekupedzisira. Kuyedzwa kunosanganisira kumhanya kwakanyanya, kushandiswa kwesimba, kugadzikana pakupisa kwakasiyana, uye kuvimbika. Kubva ipapo, kubikwa kwezvimedu kunoitwa: machipisi anorongwa zvichienderana nekushanda. Machipisi anogona kumhanya zvakadzikama pamafrequencies akakwira anoiswa mukirasi yepamusoro, nepo ayo akagadzikana chete pazvinodiwa zvakajairwa anoiswa mune imwe kirasi.
Mushure mekupasa bvunzo, chip inotumirwa kufekitari yekubatanidza michina. Munguva yekubatanidza, RAM inosungirirwa kubhodhi redunhu repiritsi, yoedzwa pamwe chete neSoC, uye yobva yaedzwa bvunzo dzemhando yepamusoro dzemidziyo dzakadai sekuongororwa kwekumanikidzwa, kuyedzwa kwekudonha, uye kuyedzwa kwekupisa.
Penutup
Maitiro ekugadzira machipisi eRAM emapiritsi musanganiswa wekugadzirwa kwakanyatsonaka, matekiniki ekugadzira anonyatsoita nanometer, uye kudzora mhando zvakanyanya padanho rega rega. Kubva kumakristaro esilicon chaiwo kusvika kumapakeji eLPDDR RAM anoshanda nesimba, zvese zvinogadzirwa kuburikidza nemaitiro akasiyana-siyana - lithography, deposition, etching, doping, capacitor formation, metal interconnection, wafer testing, cutting, and packaging and final testing. Kunyange zvazvo RAM ingaita senhamba yekugona kune vashandisi vemapiritsi, shure kwayo kune tekinoroji yekugadzira inogara ichichinja inoita kuti michina ikurumidze, ishande zvakanaka, uye ive yakavimbika.
Kana muchida, ndinogonawo kuwedzera chikamu chakatsaurirwa pamusiyano uripo pakati peLPDDR4X neLPDDR5, kana kuti nditaure zvakawanda nezve chimiro chemaseru eDRAM uye maitiro eEUV lithography.
