Mai zane Mead

**Carver Andress Mead** (an haife shi a ranar 1 ga Mayu 1934) masanin kimiyya ne kuma injiniya ɗan ƙasar Amurka. A halin yanzu yana riƙe da matsayin Farfesa Gordon da Betty Moore na Injiniya da Kimiyyar Aiwatarwa a Cibiyar Fasaha ta California (Caltech), bayan ya koyar a can sama da shekaru 40. 

Mead, wanda ya kafa fasahar zamani ta microelectronics, ya bayar da gudummawa ga haɓakawa da tsara semiconductors, kwakwalwan dijital, da masu haɗa silicon, fasahar da ke samar da tushen ƙirar guntu mai haɗaka ta zamani mai girma . Mead ya kuma shiga cikin kafa kamfanoni sama da 20.

A shekarun 1980, Mead ya mayar da hankali kan tsarin lantarki na ilimin jijiyoyi da ilmin halitta na ɗan adam, yana ƙirƙirar " tsarin lantarki na neuromorphic ."    Kwanan nan, ya yi kira da a sake fahimtar kimiyyar kimiyyar zamani, yana sake duba muhawarar ka'idar Niels Bohr, Albert Einstein da sauransu dangane da gwaje-gwajen da ci gaban kayan aiki daga baya. 

Gudummawar da Mead ya bayar a matsayinsa na malami sun haɗa da littafin tarihi na *Gabatarwa ga Tsarin VLSI* (1980), wanda ya rubuta tare da Lynn Conway . Ya kuma koyar da Deborah Chung, mace ta farko da ta kammala karatun injiniya a Caltech,  sannan ya ba wa Louise Kirkbride shawara, daliba ta farko da ta fara karatun injiniyan lantarki a makarantar.  

## Rayuwar farko da ilimi
An haifi Carver Andress Mead a Bakersfield, California, kuma ya girma a Kernville, California . Mahaifinsa ya yi aiki a wata tashar wutar lantarki a Big Creek Hydroelectric Project, mallakar Kamfanin Southern California Edison .  Carver ya halarci wata ƙaramar makaranta ta gida tsawon wasu shekaru, sannan ya koma Fresno, California don zama tare da kakarsa don ya halarci babbar makarantar sakandare.  Ya fara sha'awar wutar lantarki da kayan lantarki tun yana ƙarami, yana ganin aikin a tashar wutar lantarki, yana gwaji da kayan lantarki, yana cancanta don lasisin rediyo na ɗan lokaci, kuma yana makarantar sakandare yana aiki a tashoshin rediyo na gida. 

Mead ya yi karatun injiniyan lantarki a Caltech, inda ya sami digirinsa na farko a shekarar 1956, digirinsa na biyu a shekarar 1957, sannan digirinsa na uku a shekarar 1960.

## Microelectronics
Gudunmawar Mead ta samo asali ne daga amfani da kimiyyar lissafi ta asali zuwa ga haɓaka na'urorin lantarki, sau da yawa ta hanyoyi masu ban mamaki. A cikin shekarun 1960, ya gudanar da bincike mai tsari kan halayen makamashin electrons a cikin insulators da semiconductors, yana haɓaka fahimtar zurfin ramin electrons, halayen shinge da jigilar electrons mai zafi .  A cikin 1960, shi ne mutum na farko da ya bayyana kuma ya nuna na'urar ƙasa mai ƙarfi ta tashoshi uku bisa ga ka'idodin aiki na ramin electrons da jigilar electrons mai zafi.  A cikin 1962 ya nuna cewa ta amfani da fitar da iskar rami, electrons masu zafi suna riƙe da kuzari lokacin tafiya nisan nanometer a cikin zinare.  Nazarinsa na mahaɗan III-V (tare da WG Spitzer) ya tabbatar da mahimmancin yanayin haɗin gwiwa, yana shimfida harsashin injiniyan band-gap da haɓaka na'urorin heterojunction .    

### GaAs MESFET
A shekarar 1966, Mead ya ƙera transistor na farko na gallium arsenide field-effect ta amfani da diode mai shinge na Schottky don ware ƙofar daga tashar.  A matsayin kayan aiki, GaAs yana ba da mafi girman motsi na lantarki da saurin jikewa fiye da silicon.  GaAs MESFET ya zama babban na'urar semiconductor ta microwave, wacce ake amfani da ita a cikin nau'ikan na'urorin lantarki marasa waya iri-iri, gami da tsarin sadarwa na microwave a cikin na'urorin hangen nesa na rediyo, kwano na tauraron dan adam da wayoyin salula. Aikin Carver akan MESFETs shi ma ya zama tushen haɓaka HEMTs daga baya ta Fujitsu a 1980. HEMTs, kamar MESFETs, na'urori ne na yanayin tarawa da ake amfani da su a cikin masu karɓar microwave da tsarin sadarwa. 

### Dokar Moore
Gordon Moore ya yaba wa Mead da cewa ya ƙirƙiro kalmar dokar Moore,  don nuna hasashen da Moore ya yi a shekarar 1965 game da ƙaruwar yawan adadin sassan, "wani abu da ya kasance transistor, resistor, diode ko capacitor,"  ya dace da da'ira ɗaya mai haɗawa. Moore da Mead sun fara haɗin gwiwa a kusan 1959 lokacin da Moore ya ba wa Mead transistors "kwaskwarima" daga Fairchild Semiconductor don ɗalibansa su yi amfani da su a cikin azuzuwan sa. A cikin shekarun 1960, Mead ya yi ziyara ta mako-mako zuwa Fairchild, yana ziyartar dakunan gwaje-gwaje na bincike da haɓakawa kuma yana tattauna aikinsu da Moore. A lokacin ɗaya daga cikin tattaunawarsu, Moore ya tambayi Mead ko ramin lantarki zai iya iyakance girman transistor mai aiki. Lokacin da aka gaya masa cewa zai yi, ya tambayi menene iyaka. 

Da tambayar Moore ta motsa shi, Mead da ɗalibansa suka fara nazarin abubuwan da za su iya faruwa ta hanyar kimiyyar lissafi, suna ƙoƙarin tantance ƙanƙantar iyaka ga Dokar Moore. A shekarar 1968, Mead ya nuna, sabanin zato na yau da kullun, cewa yayin da transistors ke raguwa a girma, ba za su zama masu rauni ko zafi ko tsada ko jinkiri ba. Maimakon haka, ya yi jayayya cewa transistors za su yi sauri, mafi kyau, sanyi da rahusa yayin da aka rage su.  Sakamakonsa ya fara fuskantar shakku mai yawa, amma yayin da masu ƙira suka gwada, sakamakon ya goyi bayan ikirarinsa.  A shekarar 1972, Mead da ɗalibin digiri Bruce Hoeneisen sun annabta cewa za a iya yin transistors ƙanƙanta har zuwa microns 0.15. Wannan ƙarancin iyaka ga girman transistor ya yi ƙanƙanta fiye da yadda aka zata gabaɗaya.  Duk da shakku na farko, hasashen Mead ya shafi ci gaban masana'antar kwamfuta na fasahar submicron.  Lokacin da aka cimma burin da Mead ya annabta a cikin ainihin ci gaban transistor a shekarar 2000, transistor ɗin ya yi kama da wanda Mead ya bayyana a farko. 

### Tsarin VLSI na Mead-Conway
Mead shi ne na farko da ya yi hasashen yiwuwar ƙirƙirar miliyoyin transistors a kan guntu. Hasashensa ya nuna cewa dole ne a sami manyan canje-canje a fasaha don cimma irin wannan ƙarfin haɓakawa. Mead yana ɗaya daga cikin masu bincike na farko da suka binciki dabarun haɗakarwa mai girma, ƙira da ƙirƙirar ƙananan kwakwalwan kwamfuta masu rikitarwa. 

Ya koyar da kwas ɗin ƙira na LSI na farko a duniya, a Caltech a shekarar 1970. A cikin shekarun 1970, tare da shiga da kuma ra'ayoyin da aka samu daga azuzuwan da suka biyo baya, Mead ya haɓaka ra'ayoyinsa na ƙirar da'ira da tsarin da aka haɗa. Ya yi aiki tare da Ivan Sutherland da Frederick B. Thompson don kafa kimiyyar kwamfuta a matsayin sashe a Caltech, wanda ya faru a hukumance a shekarar 1976.   Haka kuma a shekarar 1976, Mead ya rubuta rahoton DARPA tare da Ivan Sutherland da Thomas Eugene Everhart, inda ya tantance iyakokin ƙera na'urorin lantarki na zamani kuma ya ba da shawarar yin bincike kan tasirin ƙirar tsarin na "da'irori masu girma da aka haɗa". 

Tun daga shekarar 1975, Carver Mead ya yi aiki tare da Lynn Conway daga Xerox PARC .  Sun ƙirƙiro rubutun da ya zama muhimmin abu *Gabatarwa ga tsarin VLSI*, wanda aka buga a shekarar 1979, muhimmin jagora na juyin juya halin Mead da Conway .  Littafin karatu ne na farko, wanda aka yi amfani da shi a cikin ilimin da'ira na VLSI a duk faɗin duniya tsawon shekaru da yawa.  Yaɗuwar babi na farko na bugawa a cikin azuzuwa da sauran masu bincike ya jawo hankalin jama'a sosai kuma ya haifar da al'umma ta mutane masu sha'awar hanyar.  Sun kuma nuna yuwuwar hanyar raba-wafer mai ayyuka da yawa, suna ƙirƙirar guntu ga ɗalibai a cikin azuzuwan su.    

## Manazarta