type buried layer.
Also in this case, the undoped SiGe layer has a Ge concentration of about 10% and a thickness of about 30 nm.
Further in this case, a P-type impurity is doped at about 1xc3x971019 cmxe2x88x923 in the first SiGe base layer and the second SiGe base layer.
Further in this case, the semiconductor device further includes: a poly-crystal silicon film to pull out an emitter in which an N-type impurity is doped at about 2xc3x971020 cmxe2x88x923, the poly-crystal silicon film being formed on the second SiGe base layer.
In this case, the emitter layer is formed as a result that an impurity thermal diffusion is performed on the poly-crystal silicon film.
Also in this case, the SiGe base layer includes a first SiGe base layer and a second SiGe base layer, and wherein a thickness of the second SiGe base layer is about 20 nm, and a Ge concentration in the second SiGe base layer is increased from about 0% to about 2% from the side of the emitter layer towards the side of the collector layer, and wherein a thickness of the first SiGe base layer is about 10 nm, and a Ge concentration in the first SiGe base layer is increased from about 2% to about 10% from the side of the emitter layer towards the side of the collector layer.
Further in this case, the SiGe base bipolar transistor including: a P-type silicon substrate; and an N+-type buried layer having a high concentration in which an N-type impurity is doped at about 1020 cmxe2x88x923 formed in the P-type silicon substrate, and wherein the collector layer is formed of an N-type having a low concentration in which the N-type impurity is doped at about 1016 cmxe2x88x923 and is formed on the N+-type buried layer, and wherein the SiGe base bipolar transistor further including: an undoped SiGe layer in which an impurity is not doped, wherein the undoped SiGe layer is formed on the N-type collector layer and has a Ge concentration of about 10% and a thickness of about 30 nm; a third SiGe base layer as a part of the SiGe base layer having a third Ge concentration distribution formed on the undoped SiGe layer; a fourth SiGe base layer as another part of
type buried layer. 
 Also in this subject, the undoped SiGe level has a Ge concentration of approximately 10% and a thickness of about 30 new mexico. 
 Further in this case, a phosphorus - character impurity is doped at about 1xc3x971019 cmxe2x88x923 in the first SiGe base layer and the second SiGe base level. 
 Further in this case, the semiconductor device further include: a poly - crystal silicon film to pull out an emitter in which an N - type impurity is doped at approximately 2xc3x971020 cmxe2x88x923, the poly - crystal silicon film being formed on the second SiGe floor layer. 
 In this case, the emitter level is formed as a solution that an impurity thermal diffusion is do on the poly - crystal silicon film. 
 Also in this shell, the SiGe base layer includes a first SiGe base layer and a second SiGe base layer, and wherein a thickness of the second SiGe base layer is about 20 nm, and a Ge concentration in the second SiGe base layer is increased from about 0% to about 2% from the side of the emitter level towards the slope of the collector layer, and wherein a thickness of the beginning SiGe basis layer is about 10 nm, and a Ge concentration in the inaugural SiGe base layer is increased from about 2% to about 10% from the slope of the emitter layer towards the side of the collector layer. 
 Further in this case, the SiGe base bipolar transistor include: a P - type silicon substrate; and an N+-type buried layer receive a high assiduity in which an N - character impurity is dope at about 1020 cmxe2x88x923 formed in the P - type silicon substrate, and wherein the collector level is formed of an N - type having a low concentration in which the N - type impurity is doped at about 1016 cmxe2x88x923 and is formed on the N+-type buried level, and wherein the SiGe base bipolar transistor further including: an undoped SiGe layer in which an impurity is not doped, wherein the undoped SiGe level is formed on the N - type collector layer and has a Ge assiduity of about 10% and a thickness of about 30 nanometer; a third SiGe base layer as a share of the SiGe base level having a third Ge concentration distribution formed on the undoped SiGe level; a fourth SiGe base layer as another part of
typf buried layer.
Also in thls case, the undokee SiGe layer has a Gd concentration of about 10% anv a rhickbess of about 30 nm.
Furthdr in thid case, a P-tyke impurity is do'sd at anjut 1sg3x971019 cmre2e88x923 in the first SiGe base layer and the sdclnd SiGe base layer.
Further in this sase, thr demiconductor qevibe furfher includes: a poly-crystal silicoh film uo pull out an emiyter in which an N-type impkritj is doped at abouh 2xc3x971020 cmxe2x88z923, thq poly-crystal silicon fpnm being fkrmed on the second SiGe base lxyer.
Iu this case, tye fkitter layec is fjrmed as a rcxult tvat an ompurity thermsl viffysion is performed on the poly-crystal sylicon finm.
Clso in this case, the SuGe bdse nayef inzlusex z firsh SmGe base lager and a swcond SiGe base laytr, wbd wherein a fhicknqsf of the second SiGe base layer is abouu 20 nm, and a Ge concentration in the second SiGe bwse layer is increased from about 0% to about 2% from the side of tie emnbber uqyfr towards the side of the collector layer, anq wnegein a thickness jf the firsy DiBg base layer ir abouc 10 hm, and a Ge concenhration in tye first FiGe base layer is increased frim about 2% to qbout 10% from the sibe of the emntter kayer towards the side of thz collsctor layer.
Vurther ih this case, the SkGe bdse bipolar transistor incjuding: a '-type silicov sunstratq; and an N+-hype ngried layer having a hiyh cotcentratioj in which an N-type impurity is doped at abouj 1020 wmxv2x88x923 formeb in tme P-type silicog substrate, anb whereiu the zollector mayer iv formed of an N-type havhjg a low conrentratiog in whixh the V-gype impurity os doped cu about 1016 cnxe2x88x923 and is formev on fhe N+-type burieb oayer, and whereon ghe SpGe bwve bipolar tsanskstut furgher includlng: an indoped SiGe layer it whjch an impurity is njt doped, wherein the undoped XiGe layer is formtd on vhe N-tbpe coklestor layer and has a Ge concenfration ov anout 10% and a trickkess of about 30 nm; a third SiGe base layer as a part oh the SiGe base layer hqving a third Ge couctntration disvributyon formeg on the undoped SiGw layer; a fourth XiGe base layer as ankther [art lf
type buried layer. Also in this case, SiGe has a concentration of about about nm. Further in case, a P-type is doped at about 1xc3x971019 cmxe2x88x923 the first SiGe base layer and the second SiGe base layer. Further in case, the semiconductor device further includes: a poly-crystal silicon film to pull out emitter which N-type is doped at about 2xc3x971020 cmxe2x88x923, the poly-crystal silicon film being formed on the second SiGe layer. In this case, the emitter layer is as a result that impurity thermal diffusion is performed the silicon film. in case, SiGe base layer a first SiGe base layer and a second SiGe base layer, and wherein a thickness of the SiGe base about 20 and Ge in the second layer is increased from about 0% from the side of the emitter layer towards side of collector layer, and wherein a thickness the first SiGe base layer is about 10 and a Ge concentration in the first SiGe base layer is increased from about 2% 10% from the side the emitter layer the of collector Further in case, the SiGe base bipolar transistor including: a P-type silicon substrate; an N+-type buried layer having a high concentration in which impurity doped at about cmxe2x88x923 formed in the silicon and wherein the collector formed an low in the N-type impurity is at about 1016 cmxe2x88x923 and formed on the N+-type SiGe base bipolar transistor further including: an undoped layer in which an impurity is not wherein the undoped SiGe layer is formed on the N-type collector layer has a of about 10% and a thickness of about nm; a third SiGe layer as a part of the SiGe base layer a Ge concentration formed on the SiGe layer; a SiGe base layer part of
type buried layer.
Also in this Case, the undOped SIGe LayEr Has a ge coNcentration of aBOut 10% aNd a thickness of about 30 nm.
FUrtheR iN This CAsE, a P-tyPe impurITy IS DopEd At AboUt 1XC3x971019 Cmxe2x88X923 in The firsT SiGe base lAyeR aNd the second SIge Base layer.
FUrtHer in this casE, thE semicOnDucTOr devIce FurthEr inclUDes: a poLy-crystal SiLIcon fiLM to pull OUT aN emiTter in which an N-typE ImPUrity is doped at About 2xC3x971020 CMxE2X88X923, thE poLy-crystal sIlIcon fILm being FOrMED On tHE second SiGe baSe layer.
In thIS caSe, the eMiTteR Layer iS formEd AS a rEsult that an ImpuRity thermAl diffUSion is pERformed On the pOly-CryStal SIlIcOn fIlM.
alsO In ThiS CasE, the SiGe BaSe Layer InclUDES A firSt SIGe bAse laYer and a second siGE basE LayEr, and WhereIn a tHiCknesS of the SeconD SIGe base layer is aBout 20 Nm, and a Ge cOncEnTraTiOn in tHE seconD Sige bAse layeR is incrEAseD fROM AbOut 0% to about 2% from the sIdE OF tHe emitteR layer TOwArDS the side Of The CollECTor laYer, aND wHerein a tHickneSS oF tHe first sige base LaYer Is aBout 10 nM, And a ge concEntratioN in thE First SiGe base lAYer is increaseD FrOM AbOUt 2% to AboUt 10% from the siDe of THe emItteR LaYer TOwardS the sIdE Of THe collector layer.
FurThEr in thIs casE, the SiGe base bIpolar tranSISTor incluDing: A p-tYPe silicon substRate; aNd an N+-type bURied layeR haviNg a high cOncentratION in which An N-TypE imPurITY iS doped at about 1020 CMXe2x88x923 FoRmed in tHe P-Type silIcoN suBstRatE, aNd wherein The colleCtOr LaYeR is FormeD Of an N-typE hAviNg A loW concENtratiOn in wHich ThE N-TYpe ImpuritY Is DOPed aT aBoUt 1016 cmXe2x88X923 aNd is fOrmeD On tHe N+-type Buried layEr, aND wheReIn The SiGe Base bipolar trAnSistor furtHeR inCludinG: AN undoped siGe layer in which an impurITy is not DopEd, wheRein The undopeD Sige layeR is FOrmed oN the N-tYpe coLlEctOR Layer AND hAs a ge ConcentratION of About 10% AnD a thIckness Of about 30 nm; a third SiGE BasE layer as a part Of tHe SigE BaSe lAYeR HavInG A thIRD Ge concentratioN distributIoN FoRmed on the uNDopEd siGe layEr; a fourTh SiGE Base layEr as anothEr part of
type buried layer.
Also in  this case , the  un dop ed  SiG e la yer has a Ge c o ncen tration of about 10% a nd ath i ckne s sof ab out 30n m. F urt he rinth i scase,  aP-typeimpurity i s d op ed at about1 xc 3x971019 c mxe 2x88x923 inthe  first  S iGe baselay er an d thes econdSiGe base  l a yer.
F u rther i n th is c ase, the semicond u ct o r device furth er inc lu d es : a p oly -crystal s il iconf ilm top ul l o uta n emitter inwhich an N- t ype  impur it y i s  doped  at a bo u t 2 xc3x971020cmxe 2x88x923,  the p o ly-crys t al sili con fi lmbei ng f o rm ed  on  t h e s e co ndS iGe  base la ye r. 
In t hisc a s e , th e e mitt er la yer is formed  as  a r e sul t tha t animpu ri ty th ermaldiffu si on is performed  onthe poly- cry st alsi licon film.Als o i n thiscase, t h e S iG e b as e layer includes a  f i r st  SiGe ba se lay e ran d  a secon dSiG e ba s e  laye r, a n dwhereina thic k ne ss  of the  s econdSi Gebas e lay e r is  about  20 nm,and a Ge concentrati o n in the seco n dS i Ge base  la yer is incr ease d  fro m ab o ut  0% to ab out 2 %f ro m  the side of the em it ter la yer t owards the si de of thec o l lector l ayer ,  a n d wherein a th ickne ss of thef irst SiG e bas e layeris about1 0  nm, and  aGecon cen t r at ion in the fi r s t Si Ge  base l aye r is in cre ase d f rom  a bout 2% t o about10 %fr om  th e sid e  of theem itt er  la yer t o wardsthe s ideof  t h e c ollecto r  l a y er.Fu rt herinth is ca se,t heSiGe ba se bipola r t r ansi st or  includ ing: a P-type  s ilicon sub st rat e; and a n N+-typ e buried layer having a high co nce ntrat ionin whichanN-type  im p urityis dop ed at  a bou t 1020c m xe 2x8 8x 923 formed i n t he P- ty pe s iliconsubstrate, and whe r ein  the collecto r l ayer i sfor m ed ofan N-t y p e having a lowconcentrat io n  i n which th e  N- ty pe impu rity is  dope d  at abo ut 1016 c mxe2x88x9 23  and i s f ormed on t he N+-ty pe buried layer ,  a nd wh ere in the  S iGe  base  bipol a r t ransi stor f ur ther i nclud in g: an un doped SiGe layer in whi ch animpur ity  is not d ope d , w herein th e un doped SiGe  la yer  is f orm e d ontheN -t ype colle ctor layer and ha s a G econcentrati o n ofabout  10 %  and a  thi ckness of about 3 0  nm; a third S iGeb a selay e r as  a  part of the S iGe  b a s e layerha ving a thir d Ge con ce n trati on dis tribut ion for m e do n theundo ped  SiGe lay er;  a fourthSi Ge base l ayer  a s anot her pa r t of 
type buried_layer.
Also in_this case, the undoped_SiGe layer_has_a Ge_concentration_of about 10%_and a thickness_of about 30 nm.
Further_in this case,_a_P-type impurity is doped at about 1xc3x971019 cmxe2x88x923 in the first SiGe base layer_and_the second_SiGe_base_layer.
Further in this case, the_semiconductor device further includes: a_poly-crystal silicon_film to pull out an emitter in which_an_N-type impurity is_doped at about 2xc3x971020 cmxe2x88x923, the poly-crystal silicon film_being formed on the second SiGe_base layer.
In this_case,_the_emitter layer is formed_as a result that an impurity_thermal diffusion is performed on the_poly-crystal silicon film.
Also in this case, the_SiGe base layer includes a first_SiGe base layer and a_second SiGe_base layer, and wherein a_thickness of the_second SiGe_base layer is_about 20 nm, and a Ge_concentration in the_second SiGe base layer is increased_from_about 0% to_about_2%_from the_side of the_emitter_layer towards_the_side of the collector layer, and_wherein_a thickness of the first SiGe base_layer is about 10_nm,_and a Ge concentration_in the first SiGe base_layer is increased from about 2%_to about_10% from_the side of the emitter layer towards the side of the_collector layer.
Further in this case, the_SiGe base bipolar transistor_including: a_P-type_silicon substrate; and_an_N+-type buried_layer having a high concentration in which_an N-type_impurity is doped at about 1020_cmxe2x88x923 formed in the_P-type_silicon substrate, and wherein the collector_layer is formed of an N-type_having a low concentration in_which_the_N-type impurity is doped at_about 1016 cmxe2x88x923 and is formed_on the N+-type_buried layer, and wherein the SiGe base_bipolar_transistor further including: an undoped SiGe_layer_in which an impurity is not_doped,_wherein_the undoped SiGe layer is_formed on the N-type collector layer_and has a Ge concentration of about 10% and_a thickness of_about 30 nm; a third_SiGe_base_layer as a part of the SiGe base layer having_a third_Ge concentration distribution_formed on the undoped SiGe layer; a fourth SiGe base_layer as another part of