Etching mmiri nke mbụ kwalitere mmepe nke ihicha ma ọ bụ usoro ntụ ntụ. Taa, akọrọ etching iji plasma aghọwo ihe bụ isiusoro etching. Plasma nwere electrons, cations na radicals. Ike etinyere na plasma na-eme ka eletrọn dịpụrụ adịpụ nke gas isi na steeti na-anọpụ iche na-apụ apụ, si otú ahụ na-atụgharị electrons ndị a ka ọ bụrụ cations.
Na mgbakwunye, enwere ike iwepu atom na-ezughị okè dị na mkpụrụ ndụ site n'itinye ume iji mepụta radicals na-anọpụ iche na eletrik. Akọrọ etching na-eji cations na radicals nke mejupụtara plasma, ebe cations bụ anisotropic (dabara maka etching na ntụziaka ụfọdụ) na radicals bụ isotropic (dabara maka etching na ntụziaka niile). Ọnụ ọgụgụ nke radicals dị nnọọ ukwuu karịa ọnụ ọgụgụ cations. N'okwu a, etching akọrọ kwesịrị ịbụ isotropic dị ka mmiri etching.
Otú ọ dị, ọ bụ anisotropic etching nke akọrọ etching na-eme ka ultra-miniaturized sekit kwere omume. Gịnị kpatara nke a? Na mgbakwunye, ọsọ etching nke cations na radicals na-adị ngwa ngwa. Yabụ kedu ka anyị ga-esi tinye usoro etching plasma na mmepụta nke ukwuu n'agbanyeghị adịghị ike a?
1. Akụkụ akụkụ (A/R)
Ọnụ ọgụgụ 1. Echiche nke akụkụ akụkụ na mmetụta nke ọganihu nkà na ụzụ na ya
Akụkụ akụkụ bụ nha nke obosara kehoraizin ruo ogologo kwụ ọtọ (ya bụ, ịdị elu kewara site na obosara). Obere akụkụ dị oke egwu (CD) nke sekit ahụ, ka uru akụkụ dị ukwuu na-abawanye. Nke ahụ bụ, na-eche na uru akụkụ nke 10 na obosara nke 10nm, ịdị elu nke oghere a kụpụrụ n'oge usoro etching kwesịrị ịbụ 100nm. Ya mere, maka ngwaahịa na-esote ọgbọ na-achọ ultra-miniaturization (2D) ma ọ bụ njupụta dị elu (3D), a chọrọ ụkpụrụ oke akụkụ dị elu iji hụ na cations nwere ike ịbanye na fim dị ala n'oge etching.
Iji nweta teknụzụ ultra-miniaturization nke nwere akụkụ dị oke egwu nke na-erughị 10nm na ngwaahịa 2D, a ga-edobe uru akụkụ nke capacitor nke ebe nchekwa ohere ohere ike (DRAM) karịa 100. N'otu aka ahụ, ebe nchekwa 3D NAND flash na-achọkwa ụkpụrụ oke akụkụ dị elu. ka ikpokọta 256 n'ígwé ma ọ bụ karịa nke cell stacking layers. Ọbụlagodi na emezuru ọnọdụ achọrọ maka usoro ndị ọzọ, enweghị ike imepụta ngwaahịa achọrọ ma ọ bụrụ nausoro etchingerughi ọkọlọtọ. Nke a bụ ya mere teknụzụ etching ji na-adịwanye mkpa.
2. Nchịkọta nke etching plasma
Ọgụgụ 2. Ịchọpụta gas isi iyi plasma dị ka ụdị ihe nkiri si dị
Mgbe a na-eji ọkpọkọ oghere eme ihe, ka dayameta ọkpọkọ dị warara, ọ na-adị mfe maka mmiri mmiri ịbanye, nke bụ ihe a na-akpọ capillary phenomenon. Otú ọ dị, ọ bụrụ na a ga-egwupụta oghere (njedebe mechiri emechi) na ebe a na-ekpughere ya, ntinye nke mmiri mmiri na-esiwanye ike. Ya mere, ebe ọ bụ na nha dị oke egwu nke sekit bụ 3um ruo 5um n'etiti 1970s, akọrọ.etchingejirila nwayọọ nwayọọ dochie mmiri etching dị ka ihe bụ isi. Ya bụ, ọ bụ ezie na ionized, ọ dị mfe ịbanye n'ime oghere dị omimi n'ihi na olu nke otu molekul dị ntakịrị karịa nke ihe ngwọta polymer polymer.
N'oge etching plasma, ime ụlọ nhazi eji eme ihe etching kwesịrị imezigharị ka ọ bụrụ ọnọdụ oghere tupu ịgbanye gas isi iyi plasma dabara adaba maka oyi akwa dị mkpa. Mgbe a na-emepụta ihe nkiri oxide siri ike, a ga-eji gasị ikuku sitere na carbon fluoride siri ike mee ihe. Maka ihe nkiri sịlịkọn ma ọ bụ ihe nkiri igwe na-esighị ike, ekwesịrị iji gas isi iyi nke chlorine.
Yabụ, kedu ka esi etinye oyi akwa ọnụ ụzọ ámá na silicon dioxide (SiO2) na-ekpuchi oyi akwa?
Nke mbụ, maka oyi akwa ọnụ ụzọ ámá, ekwesịrị iwepụ silicon site na iji plasma chlorine (silicon + chlorine) na polysilicon etching selectivity. Maka oyi akwa mkpuchi nke ala, a ga-etinye ihe nkiri sịlịkọn dioxide n'ime nzọụkwụ abụọ site na iji carbon fluoride nke sitere na plasma gas (silicon dioxide + carbon tetrafluoride) na nhọrọ na arụmọrụ siri ike.
3. Reactive ion etching (RIE ma ọ bụ physicochemical etching) usoro
Ọgụgụ 3. Uru nke reactive ion etching (anisotropy na elu etching ọnụego)
Plasma nwere ma isotropic free radicals na anisotropic cations, yabụ kedu ka o si arụ etching anisotropic?
A na-arụkarị etching akọrọ Plasma site na reactive ion etching (RIE, Reactive Ion Etching) ma ọ bụ ngwa dabere na usoro a. Ihe bụ isi nke usoro RIE bụ ime ka ike nke njikọ dị n'etiti ụmụ irighiri ihe dị na fim ahụ kwụsị site na iji cations anisotropic wakpo mpaghara etching. Ebe a na-esighị ike na-etinye uche site na free radicals, jikọtara ya na ihe ndị mejupụtara oyi akwa ahụ, ghọọ gas (ihe na-agbanwe agbanwe) ma hapụ ya.
Ọ bụ ezie na free radicals nwere àgwà isotropic, ụmụ irighiri ihe na-eme ka elu ala (ndị ike njide na-ebelata site na mbuso agha nke cations) na-ejide ya ngwa ngwa site na free radicals ma ghọọ ogige ọhụrụ karịa mgbidi dị n'akụkụ na ike njide siri ike. Ya mere, itching ala na-aghọ isi ihe. Ihe ndị ahụ ejidere na-aghọ gas nwere radicals free, bụ nke a na-ehichapụ ma hapụ ya n'elu n'okpuru ọrụ nke agụụ.
N'oge a, a na-ejikọta cations ndị a na-enweta site na omume anụ ahụ na free radicals nwetara site na kemịkal na-ejikọta maka anụ ahụ na nke kemịkal, na ọnụ ọgụgụ etching (Etch Rate, ogo nke etching na oge ụfọdụ) na-abawanye ugboro 10. ma e jiri ya tụnyere cationic etching ma ọ bụ free radical etching naanị. Usoro a nwere ike ọ bụghị naanị ịbawanye ọnụ ọgụgụ etching nke anisotropic ala etching, kamakwa dozie nsogbu nke ihe fọdụrụ na polymer mgbe etching gasịrị. A na-akpọ usoro a reactive ion etching (RIE). Isi ihe na-eme ka ihe ịga nke ọma nke RIE etching bụ ịchọta gas isi iyi plasma kwesịrị ekwesị maka itching ihe nkiri ahụ. Mara: Plasma etching bụ RIE etching, enwere ike were ha abụọ dịka otu echiche.
4. Etch Rate na Core Performance Index
Onyonyo 4. Core Etch Performance Index metụtara Etch Rate
Ọnụego ntanye na-ezo aka na omimi ihe nkiri a na-atụ anya iru n'ime otu nkeji. Yabụ kedu ihe ọ pụtara na ọnụego etch dịgasị iche site na akụkụ gaa na otu wafer?
Nke a pụtara na omimi etch dịgasị iche site n'akụkụ ruo akụkụ na wafer. N'ihi nke a, ọ dị ezigbo mkpa ịtọ ebe njedebe (EOP) ebe etching kwesịrị ịkwụsị site n'ịtụle nkezi ọnụego etch na etch omimi. Ọbụna ma ọ bụrụ na edobere EOP, a ka nwere ebe ụfọdụ ebe omimi etch dị omimi (n'elu-etched) ma ọ bụ na-emighị emi (n'okpuru-etched) karịa ka e mere atụmatụ na mbụ. Otú ọ dị, n'okpuru-etching na-akpata mmebi karia itching n'oge etching. N'ihi na ọ bụrụ na ọ dị n'okpuru-etching, akụkụ ahụ na-adịghị mma ga-egbochi usoro ndị na-esote dị ka ntinye ion.
Ka ọ dị ugbu a, nhọrọ (nke a na-atụ site na ọnụego etch) bụ ihe ngosipụta arụmọrụ dị mkpa nke usoro etching. Ụkpụrụ nha dabere na ntụnyere ọnụ ọgụgụ etch nke oyi akwa mkpuchi (ihe nkiri foto, ihe nkiri oxide, ihe nkiri silicon nitride, wdg) na oyi akwa ebumnuche. Nke a pụtara na ka elu selectivity, ngwa ngwa iche oyi akwa na-etched. Ka ọkwa dị elu nke miniaturization dị elu, ihe dị elu nke nhọrọ nhọrọ bụ iji hụ na enwere ike igosi usoro dị mma nke ọma. Ebe ọ bụ na ntụziaka etching kwụ ọtọ, nhọrọ nke cationic etching dị ala, ebe nhọrọ nke radical etching dị elu, nke na-eme ka nhọrọ RIE dịkwuo mma.
5. Etching usoro
Ọgụgụ 5. Usoro etching
Nke mbụ, a na-etinye wafer n'ime ọkụ oxidation nke nwere okpomọkụ dị n'etiti 800 na 1000 ℃, mgbe ahụ, a na-emepụta ihe nkiri silicon dioxide (SiO2) nke nwere ihe mkpuchi dị elu n'elu wafer site na usoro akọrọ. Na-esote, a na-abanye usoro nkwụnye ego iji mepụta oyi akwa silicon ma ọ bụ ihe na-eduzi ihe nkiri na ihe nkiri oxide site na ntinye nke vapor deposition (CVD) / anụ ahụ vapor deposition (PVD). Ọ bụrụ na emebere oyi akwa silicon, enwere ike ịme usoro mgbasa nke adịghị ọcha iji welie conductivity ma ọ bụrụ na ọ dị mkpa. N'oge usoro mgbasa nke adịghị ọcha, a na-agbakwunye ọtụtụ adịghị ọcha ugboro ugboro.
N'oge a, a ga-ejikọta oyi akwa mkpuchi na akwa polysilicon maka etching. Nke mbụ, a na-eji photoresist. Mgbe nke ahụ gasịrị, a na-etinye ihe nkpuchi na ihe nkiri fotoresist na ikpughe mmiri na-eme site n'imikpu iji depụta ụkpụrụ achọrọ (adịghị ahụ anya na anya gba ọtọ) na ihe nkiri fotoresist. Mgbe e gosipụtara usoro ihe omume ahụ site na mmepe, a na-ewepụ fotoresist na mpaghara foto. Mgbe ahụ, a na-ebufe wafer nke usoro fotolithography na-edozi na usoro etching maka etching akọrọ.
A na-emekarị etching akọrọ site na reactive ion etching (RIE), bụ nke a na-emeghachi ya ugboro ugboro site na dochie isi iyi gas kwesịrị ekwesị maka ihe nkiri ọ bụla. Ma etching akọrọ na mmiri etching na-achọ ịbawanye akụkụ (uru A/R) nke etching. Tụkwasị na nke ahụ, a na-achọ ihicha mgbe nile iji wepụ polymer na-akwakọba na ala nke oghere (ohere nke etching). Ihe dị mkpa bụ na mgbanwe niile (dị ka ihe, isi iyi gas, oge, ụdị na usoro) kwesịrị ka edozi ya n'ụzọ anụ ahụ iji hụ na ngwọta nhicha ma ọ bụ gas na-esi na plasma nwere ike ịdaba na ala nke tren. Mgbanwe dị nta na mgbanwe na-achọ ka a gbakọọ mgbanwe ndị ọzọ, na usoro nchigharịgharị a na-emegharị ugboro ugboro ruo mgbe ọ zutere nzube nke ọkwa ọ bụla. N’oge na-adịbeghị anya, akwa monoatomic dị ka akwa atomic Layer deposition (ALD) adịla gịrịgịrị ma sie ike karị. Ya mere, teknụzụ etching na-aga n'ihu iji obere okpomọkụ na nrụgide. Usoro etching na-achọ ijikwa akụkụ dị oke egwu (CD) iji mepụta usoro dị mma ma hụ na a na-ezere nsogbu ndị sitere na usoro etching, karịsịa n'okpuru-etching na nsogbu ndị metụtara iwepụ ihe fọdụrụ. Edemede abụọ a dị n'elu maka etching bụ iji nye ndị na-agụ akwụkwọ nghọta nke ebumnuche nke usoro etching, ihe mgbochi iji nweta ebumnuche ndị a dị n'elu, yana ihe ngosi arụmọrụ ejiri iji merie ihe mgbochi ndị dị otú ahụ.
Oge nzipu: Sep-10-2024