Fasahar Ƙirƙirar Na'urar Firikwensin Kyamara akan Wayoyin Salula
Ci gaban kyamarorin wayar salula a cikin shekaru goma da suka gabata abin mamaki ne. Hotunan da a da suka kasance "masu kyau ga takardu" yanzu suna iya kusantar ingancin kyamarorin da aka keɓe a yanayi da yawa. Wannan ci gaban ba wai kawai yana faruwa ne ta hanyar software na sarrafa hotuna ba, har ma da fasahar ƙera na'urori masu auna kyamara - manyan abubuwan da ke canza haske zuwa siginar lantarki. A bayan siraran na'urar kyamara akwai wani tsari mai rikitarwa, mai inganci, kuma mai ci gaba da haɓaka masana'antar semiconductor don magance ƙalubalen ƙananan girma, ƙarancin amfani da wutar lantarki, da ingancin hoto mai yawa.
1. Matsayin na'urori masu auna firikwensin da yanayinsu a fasahar kyamarar wayar salula
Na'urorin firikwensin kyamarar wayar salula gabaɗaya suna dogara ne akan CMOS (Karin Metal-Oxide Semiconductor). Idan aka kwatanta da na'urorin firikwensin CCD da aka taɓa amfani da su a da, CMOS ya fi ƙarfin aiki, yana da saurin karantawa, kuma yana da sauƙin haɗawa da da'irorin sarrafa sigina akan guntu ɗaya. Abubuwan da ke haifar da haɓaka na'urorin firikwensin wayar salula sun haɗa da: ƙara ƙuduri (har zuwa goma ko ma ɗaruruwan megapixels), ingantaccen aiki mai ƙarancin haske, ƙarfin bidiyo mai ƙuduri mai girma, HDR na ainihin lokaci, saurin mayar da hankali kan atomatik, da tallafi don ɗaukar hoto na kwamfuta.
Duk waɗannan buƙatun suna tilasta masana'antun firikwensin su inganta tsarin pixel, kayan aiki, hanyoyin lithography, ƙirar da'ira, har ma da yadda suke tara layukan guntu don kiyaye siriri yayin da suke inganta aiki.
2. Tsarin asali na firikwensin CMOS: daga photons zuwa bayanai
A taƙaice dai, kowanne pixel da ke kan firikwensin CMOS ya ƙunshi yankin photodiode don ɗaukar haske da ƙananan transistor don karantawa da faɗaɗa siginar. Lokacin da photons suka shiga, photodiode yana samar da electrons (cajin lantarki) daidai da ƙarfin haske. Sannan ana karanta wannan cajin ta hanyar da'irar karantawa, wanda ADC (Analog-to-Digital Converter) ya mayar da shi zuwa bayanai na dijital, sannan a ƙara sarrafa shi zuwa hoto.
Duk da haka, ƙirar aiki ta fi rikitarwa: kowane pixel dole ne ya rage hayaniya, ƙara kewayon motsi, hana magana ta hanyar sadarwa (zubar haske ko caji zuwa pixels maƙwabta), kuma ya kula da babban jin daɗi koda girman pixel yana ci gaba da raguwa.
3. Matakin ƙera Wafer: tushen ƙera firikwensin
Ƙirƙirar na'urar firikwensin kyamara tana farawa da wafers na silicon, kamar yadda yake a sauran masana'antun semiconductor. Manyan hanyoyin sun haɗa da:
1. Haɓaka iskar oxygen da kuma siraran fim
Ana shafa wafer ɗin da wani abu mai rufi ko mai gudanarwa (misali SiO₂, poly-silicon, wasu ƙarfe) ta amfani da tsari kamar CVD (Chemical Vapor Deposition) ko PVD (Physical Vapor Deposition).
2. Ɗaukar Hoto
Ana "buga" tsarin da'ira da tsarin pixel ta amfani da na'urar daukar hoto sannan a fallasa su ga haske ta hanyar abin rufe fuska. Ƙaramin fasahar aiwatarwa, haka lithography ɗin yake buƙata.
3. Sassaka
Ana cire wasu sassan layin don samar da tsarin, ko dai ta hanyar gogewa da ruwa ko kuma gogewa da busasshiyar hanya (plasma).
4. Yin amfani da maganin hana shan kwayoyi / dasa ion
Ana dasa wasu ions a cikin silicon don samar da yankunan N da P, waɗanda suke da mahimmanci ga photodiodes da transistor su yi aiki bisa ga takamaiman bayanai.
5. Ƙarfe da haɗin kai
Ana ƙirƙirar waƙoƙin ƙarfe don haɗa transistor, ƙwaƙwalwa, da tubalan sarrafawa a cikin guntu.
A cikin na'urori masu auna kyamara, ƙirƙirar pixel ba wai kawai yana mai da hankali kan transistor ba, har ma yana mai da hankali kan inganta photodiodes da tsarin micro-optical da ke sama da su. Kalubalen shine tabbatar da cewa kayan lantarki da na gani suna aiki cikin jituwa a cikin ƙaramin yanki.
4. Hasken Baya (BSI): juyin juya hali a cikin hankali
Ɗaya daga cikin manyan sabbin abubuwa a cikin na'urorin firikwensin wayar hannu shine BSI (Backside Illumination). A cikin na'urori masu firikwensin gargajiya (Frontside Illumination/FSI), haske yana shiga daga gefe ɗaya da layin ƙarfe da transistor. Sakamakon haka, wasu daga cikin hasken suna toshewa ta hanyar wayoyi da kewaye, wanda ke rage saurin amsawa.
A cikin BSI, ana sarrafa wafer ɗin ta yadda haske zai shiga daga "baya" (gefen ba tare da toshe hanyoyin haɗin ba). Ana samun wannan ta hanyar rage wafer ɗin da kuma motsa layukan haɗin zuwa ɗayan gefen. Sakamakon:
- ƙarin haske yana kaiwa ga photodiode,
- ingantaccen aikin haske mai sauƙi,
- ingantaccen aiki na kwantum,
- ya dace da ƙananan pixels.
Tsarin BSI yana buƙatar tsauraran matakan sarrafa sinadarai da injina yayin da ake rage girman wafer, domin kauri mai yawa zai iya rage yawan amfanin ƙasa (yawan nasarar samarwa) ko kuma ya sa wafer ɗin ya yi saurin fashewa.
5. CMOS mai tarin yawa: an tara su don hanzarta da kuma wadatar da ayyuka
Domin ƙara gudu da kuma ƙara fasali ba tare da ƙara girma ba, masana'antar tana amfani da na'urori masu auna firikwensin da aka tara. Manufar: raba layin pixel da layin dabaru zuwa wafers daban-daban, sannan a haɗa su ta amfani da fasahar haɗin kai mai yawa (misali, haɗin haɗin gwiwa ko TSV—Through-Silicon Via).
Amfanin CMOS mai tarawa:
- Karatu cikin sauri, ya dace da bidiyo mai sauri, hotuna masu fashewa, kuma yana rage rufewa mai birgima.
- Ana iya ƙara ƙarin dabaru da ƙwaƙwalwa (misali buffers/DRAM akan wasu ƙira) ba tare da yin watsi da yankin pixel ba.
- Sarrafa firikwensin kamar sauri HDR mai ɗaukar hotuna da yawa ko kuma autofocus mai amsawa.
A fannin ƙera wafer, daidaita shi yana buƙatar daidaito sosai. Manyan ƙalubalen sune kiyaye ingancin haɗuwa, rage juriya, ƙara yawan amfanin ƙasa, da kuma kiyaye ƙarancin farashin samarwa.
6. Fasaha ta pixel: ƙananan tabarau, CFA, da kuma keɓewa
A saman photodiode, akwai abubuwa masu mahimmanci na micro optical:
– Microlens: ƙaramin ruwan tabarau a saman kowane pixel don "tattara" haske zuwa yankin aiki na photodiode. A kan wayoyin komai da ruwanka masu ƙananan ruwan tabarau na kyamara, ƙananan ruwan tabarau suna taimakawa wajen ƙara yawan hasken da ke isa pixel yadda ya kamata.
– Tsarin Tace Launi (CFA): matatar launi (yawanci tsarin Bayer ko bambance-bambancen da ke cikinsu) wanda ke ba da damar na'urar firikwensin ta bambance launuka. Ana ƙirƙirar CFAs ta hanyar adanawa da tsara kayan polymer masu launi.
– Rarraba Zurfi (DTI): ramin keɓewa wanda aka cika da kayan rufewa don hana yin magana tsakanin pixels. DTI yana zama mahimmanci yayin da girman pixel ke raguwa kuma hanyoyin ruwan tabarau ke ƙaruwa.
Haɗin ƙananan tabarau, CFA, da DTI gada ce tsakanin duniyar gani da ta lantarki. Ƙananan kurakurai a cikin kauri na yadudduka, matsayi, ko daidaito na iya shafar daidaiton launi, kaifi, da hayaniya.
7. Gano Tsarin Aiki Mai Sauƙi (PDAF) da pixels na musamman
Yawancin wayoyin zamani suna amfani da PDAF (Phase Detection Autofocus) akan firikwensin. Wannan ya haɗa da pixels na musamman, ko yankuna, waɗanda ke karɓar haske daga takamaiman sassan buɗewar ruwan tabarau kuma suna ƙididdige bambance-bambancen matakai don tantance alkibla da girman daidaitawar mayar da hankali.
Aiwatar da PDAF yana buƙatar ƙira daban-daban na CFA da microlens don takamaiman pixels, ko tsarin rufe fuska na micro. Wannan yana ƙara wa sarkakiyar samarwa saboda ba duk pixels iri ɗaya bane. Kalubalen shine a tabbatar da cewa pixels na PDAF ba sa yin illa ga ingancin hoto (misali, gabatar da kayan tarihi), yayin da ake kiyaye daidaiton mayar da hankali.
8. HDR, samun sauyi biyu, da kuma ƙirar gine-gine na karatu
Baya ga inganta "kama haske", ƙirƙirar firikwensin yana da alaƙa da tsarin da'ira:
- Samun Canzawa Biyu (DCG) yana bawa firikwensin damar canzawa tsakanin yanayin babban hankali da yanayin kewayon mai ƙarfi, ya danganta da yanayin haske.
- HDR mai fallasa da yawa yana buƙatar karantawa cikin sauri da kuma daidaitaccen sarrafa lokaci.
– Murfin duniya (kodayake ya fi yawa a kyamarorin masana'antu) muhimmin batu ne da za a shawo kan murfin da ke birgima, amma yana da wahalar aiwatarwa a wayoyin komai da ruwanka saboda yana buƙatar capacitor na ajiya na caji a kowace pixel ko ƙarin ƙira wanda ke ƙara sarari da rikitarwa.
Duk waɗannan fasalulluka suna shafar tsarin transistor, adadin layukan ƙarfe, amfani da wutar lantarki, da zafi—masu mahimmanci a cikin na'urori masu siriri waɗanda ke da ƙarancin rayuwar baturi.
9. Gwaji, daidaitawa, da haɗakar na'urori
Da zarar an sarrafa wafer ɗin, matakai masu mahimmanci na gaba sune:
- Gwajin matakin Wafer don duba matattun pixels, hayaniya, daidaito, da sigogin lantarki.
– Yanka (yanka wafer ɗin zuwa guntu), sannan a marufi wanda ke kare guntu ɗin kuma yana samar da haɗi.
– Daidaitawa: ya haɗa da gyaran taswirar hayaniya, inuwa, daidaiton fari, da halayen ruwan tabarau. Ana yin abubuwa da yawa na daidaitawa lokacin da aka haɗa na'urar kyamara kuma aka gwada ta.
– Haɗin kai a cikin na'urar: ana haɗa firikwensin da ruwan tabarau, OIS (tsayawa a hoton gani) idan akwai, da sauran abubuwan tallafi. Daidaito na inji (karkatarwa, nisan mayar da hankali) yana shafar kaifi sosai.
A wayoyin komai da ruwanka, na'urorin kyamara dole ne su cika ƙa'idodin juriya yayin da suke da araha kuma ana iya samarwa da yawa.
10. Umarni na gaba: ƙarin yadudduka da kwamfuta kusa da firikwensin
A nan gaba, fasahar ƙera na'urori masu auna firikwensin wayar salula za ta iya ci gaba zuwa ga:
- Tarin abubuwa masu ƙarfi tare da haɗin kai mai santsi da layuka masu tsauri.
- AI/ƙirƙirar firikwensin akan firikwensin don rage hayaniya, gano yanayi, ko HDR nan take tare da ƙarancin latency.
- Pixels masu wayo tare da tsarin gine-gine wanda ke rage hayaniya da ƙara kewayon motsi ba tare da ƙara megapixels kawai ba.
- Sabbin kayayyaki da tsare-tsare waɗanda ke ƙara ingancin ɗaukar haske da kuma hana magana ta hanyar sadarwa a cikin ƙananan pixels.
Ko da kuwa yayin da daukar hoto na kwamfuta ke ƙara zama ruwan dare, ingancin bayanan firikwensin da ba a sarrafa ba ya ci gaba da zama muhimmi. Saboda haka, sabbin abubuwan ƙirƙira—daga BSI, DTI, zuwa tarin CMOS—za su ci gaba da zama mahimmanci.
Kammalawa
Fasahar ƙirƙirar firikwensin kyamara ta wayar salula ta haɗa daidaiton semiconductor da injiniyan gani na micrometer. Daga lithography na wafer da doping, zuwa rage nauyi don BSI, tara guntu don firikwensin da aka tara, zuwa microlens da ƙera CFA, duk hanyoyin an tsara su ne don ba wa ƙananan firikwensin damar ɗaukar haske yadda ya kamata, cikin sauri, da kuma daidai. Sakamakon shine kyamarorin wayar salula masu inganci a cikin yanayi daban-daban, yayin da suke share hanyar sabbin fasaloli kamar HDR na ainihin lokaci, autofocus mai sauri, da bidiyo mai inganci a cikin na'urori waɗanda suka kasance masu ƙanƙanta.
Idan kuna so, zan iya ƙarawa: (1) misali na yadda ake gudanar da aikin ƙira a cikin nau'in maki mataki-mataki, (2) ƙaramin babi na musamman wanda ke kwatanta BSI da FSI idan aka kwatanta da stacked, ko (3) jerin kalmomi (ƙamus) don sauƙaƙa wa masu karatu.
