 emitter side towards the collector side and a concentration of the second conductive type impurity is gradually reduced from the emitter side towards the collector side.
Japanese Laid Open Patent Application (JP-A-Heisei, 11-214399) discloses the following bipolar semiconductor device. The bipolar semiconductor device is provided with: a semiconductor layer having a first conductive type of a buried layer so as to form a collector region, on a substrate; a first insulation film formed on the semiconductor layer; a second conductive type of a first conductive film similarly formed on the semiconductor layer so as to form a base region, a second conductive type of a second conductive film which is formed on the first insulation film and connected to the first conductive film so as to form a base pull-out electrode; and a first conductive type of a third conductive film which is separated through a second insulation film from the second conductive film and formed on the first conductive film so as to form an emitter region, wherein the first insulation film and the second conductive film are coated with glass material insulation film, and the surface of the glass material insulation film is flat.
Japanese Laid Open Patent Application (JP-A-Heisei, 10-79394) discloses the following bipolar transistor. The bipolar transistor at least contains: a first conductive type of a single crystal silicon layer; a many-layer film composed of a first insulation film having an opening provided on a surface of the first conductive type of the single crystal silicon layer, a second conductive type of a poly-crystal layer of a conductive type opposite to the first conductive type, and a second insulation film; a first conductive type of a single crystal silicon germanium layer provided in the opening; a second conductive type of a single crystal silicon germanium layer provided on the first conductive type of the single crystal silicon germanium layer; and a second conductive type of a poly-crystal silicon germanium layer placed in contact with both the second conductive type of the single crystal silicon germanium layer and the second conductive type of the poly-crystal layer.
Moreover, Japanese Publication Patent Application (JP-B2-Heisei, 07-44185) discloses the following semiconductor device. The semiconductor device is a bipolar transistor, in which on a silicon substrate or a silicon epitaxial layer having a first conductive type, has a compound crystal layer composed of silicon and germanium, and has a second conductive type impurity layer in the compound crystal, and has a silicon layer having a first conductive type impurity on the
emitter side towards the collector side and a concentration of the second conductive type impurity is gradually dilute from the emitter slope towards the collector side. 
 Japanese Laid Open Patent Application (JP - A - Heisei, 11 - 214399) discloses the following bipolar semiconductor device device. The bipolar semiconductor device is provided with: a semiconductor level have a first conductive character of a bury layer so as to imprint a collector region, on a substrate; a first insulating material film formed on the semiconductor device layer; a second conductive character of a beginning conductive film similarly formed on the semiconductor level so as to form a base region, a second conductive type of a second conductive film which is form on the first insulation film and connected to the first conductive movie so as to form a base pull - out electrode; and a first conductive type of a third conductive film which is separate through a second insulation film from the second conductive film and formed on the first conductive film so as to form an emitter region, wherein the first insulation movie and the second conductive movie are coated with glass material insulating material movie, and the surface of the glass material insulation film is flat. 
 Japanese Laid Open Patent Application (JP - A - Heisei, 10 - 79394) discloses the following bipolar transistor. The bipolar transistor at least check: a first conductive type of a single crystal silicon layer; a many - level film composed of a first insulation film having an opening leave on a surface of the first conductive type of the single crystal silicon level, a second conductive type of a poly - crystal layer of a conductive type opposite to the first conductive type, and a second insulation film; a beginning conductive type of a unmarried crystal silicon germanium layer supply in the opening; a second conductive character of a single crystal silicon germanium layer provided on the beginning conductive type of the single crystal silicon germanium layer; and a second conductive type of a poly - quartz glass silicon germanium layer placed in contact with both the second conductive character of the single crystal silicon germanium layer and the second conductive type of the poly - quartz glass layer. 
 Moreover, Japanese Publication Patent Application (JP - B2 - Heisei, 07 - 44185) discloses the following semiconductor device device. The semiconductor device is a bipolar transistor, in which on a silicon substrate or a silicon epitaxial layer having a first conductive type, has a compound crystal level composed of silicon and germanium, and has a second conductive type impurity layer in the compound crystal, and has a silicon layer having a inaugural conductive character impurity on the
 emltter side towards the cullector side aue a coicentrafion of ghe second conductive type ilpyrity is gradually reduced wrom the vmitter sude uowards the collerfor sidc.
Lapansde Lciv Open Patent Akplication (J[-A-Heisei, 11-214399) discnored the following bipolar semiconductjr devive. The bipolar sgmicomquctkg bevice is provided with: a semicknductog layer having a girst conductive type of a burled layer so as to form a coloectje region, on x substratt; c first insolation film formed on the semicunduccor layer; a swcojg conductivx type of a first gpnducthve filk similarly fovmed mn rhe semiconductor layxr so as to form a bwse regiot, c second conductive ttpw of d sewond xonaucuivx fjlm whlch is formed on the firwt insulation film snq connected to the fyrft conductive film so as to form a base puml-out electrode; and a furst conductive type lf a thirq conductive film which is separated through a sewond mnrulcblon wull from the second conductive film and formed jh uhe first conductlve film so as to gogm wn emitter reeion, wksrsin the first insupation silm qnd the stcond conductive film are coated with glass iqterial insulation film, and tke surgace pf the glass material iusulatjon film is flat.
Japahdse Laid Open Pagenn Ap[lication (JP-A-Heisei, 10-79394) discljses the hollocing bipular transystor. The hipolar transistor at lewst clndains: a figst conductive type of a single crystal silicpn lajer; a manv-layer film composeq of a first iusulatiou film having an openinj provided og a surface ox the first cmnductivq type od the skvgle crystal solicon lajex, a secone conductive type pf x poly-crystal lavtr if a conductive tyoe jpiosmte tj the first cmnduztixr typd, and a secivd imsulation film; a firvt cknductive type of s fingle ctystal sijicon germaniim layer provided ln thx openmng; a xecjnd conductive type of a singls crystal sijicon germanyum oayer providzd on the first conductive type of the smngle crystal silicon gwrmanium layer; and c xecond condnctive type of d poly-crystal silicob germanium layer placed in contact wifh botv the second conductive type of the single crystal silicon germanium layer and the sxcjnd conductjve yype mf che polr-crydval layer.
Moreover, Japanese Publication Patent Ap'lication (BP-Y2-Heisei, 07-44185) discloses the followone semiconductur device. The semiconducfor devive is a bipolar transistor, in wnich on a silicon substrste or a silidon eppjaxmal layer having a forst cmnducrive type, hws a compound crusbal layer fomppszd of silicon and germanium, and hqs a swclnd conductive tbpe impurity uayer in thg compound crystam, ans has x silicon layrr having a fitst conductive type pmptrity on the
emitter side towards the collector side and of second conductive impurity is gradually towards collector side. Japanese Open Patent Application 11-214399) discloses the following bipolar semiconductor The bipolar semiconductor device is provided with: a semiconductor layer having a first type of a buried layer so as to form a collector region, on substrate; first film on the semiconductor layer; a second conductive type of a first conductive film similarly formed on semiconductor layer so as to form a base a second conductive type a second conductive film which formed the first film connected the first conductive so as to form a base pull-out electrode; and a first conductive type of a third conductive which is a second film the conductive film and the first conductive film so as emitter region, wherein the first insulation film and second conductive are coated with glass material insulation and the surface of the glass material insulation is flat. Japanese Laid Open Patent Application (JP-A-Heisei, 10-79394) discloses the following bipolar transistor. The at least contains: a conductive type of single silicon a film composed a first insulation film having an opening provided on a surface the first conductive type of the single crystal silicon layer, conductive of a poly-crystal of a conductive type to first conductive type, and insulation a of single silicon germanium layer provided the opening; a second conductive of a single crystal the first conductive type of the single crystal germanium layer; and a second conductive type a poly-crystal silicon germanium layer placed in contact with both the second type of crystal silicon germanium layer and the second conductive of the poly-crystal layer. Japanese Publication Patent Application (JP-B2-Heisei, 07-44185) discloses the following device. semiconductor device a bipolar transistor, which on a substrate or a layer having first type, crystal layer composed of silicon and and a second conductive type impurity in crystal, and has a silicon layer having a first conductive type impurity on the
 emitter side towards the collEctor side aNd a coNceNtrAtIon oF the Second conductiVE typE impurity is gradually reDuced FrOM the EMiTter sIde towaRDs THE coLlEcTor SiDE.
JApaneSe LAid Open patent ApplIcaTiOn (JP-A-Heisei, 11-214399) dIScLoses the foLloWing bipolar sEmiConducToR deVIce. ThE biPolar SemicoNDuctor Device is pRoVIded wiTH: a semicONDuCtor Layer having a first COnDUctive type of a bUried lAyER sO AS to ForM a collectoR rEgion, ON a substRAtE; A FIrsT Insulation filM formed on thE SemIconduCtOr lAYer; a seCond cOnDUctIve type of a fIrst ConductivE film sIMilarly FOrmed on The semIcoNduCtor LAyEr So aS tO ForM A bAse REgiOn, a seconD cOnDuctiVe tyPE OF A secOnd CondUctivE film which is fOrmEd on THe fIrst iNsulaTion FiLm and ConnecTed to ThE first conductivE filM so as to foRm a BaSe pUlL-out eLEctrodE; anD a fIrst conDuctive TYpe Of A THIrD conductive film whiCh IS SeParated tHrough A SeCoND insulatIoN fiLm frOM The seCond COnDuctive fIlm and FOrMeD on the fIrSt condUcTivE fiLm so aS To foRm an emItter regIon, whERein the first inSUlation film anD ThE SEcONd coNduCtive film arE coaTEd wiTh glASs MatERial iNsulaTiON fILm, and the surface of thE gLass maTeriaL insulation fiLm is flat.
JaPANEse Laid OPen PATeNT Application (JP-a-HeisEi, 10-79394) discloseS The folloWing bIpolar trAnsistor. THE Bipolar tRanSisTor At lEASt Contains: a firsT COnduCtIve type Of a Single cRysTal SilIcoN lAyer; a many-Layer filM cOmPoSeD of A firsT InsulatiOn FilM hAviNg an oPEning pRovidEd on A sUrFAce Of the fiRSt CONducTiVe Type Of tHe SinglE crySTal Silicon Layer, a secOnd COnduCtIvE type of A poly-crystal lAyEr of a conduCtIve Type opPOSite to thE first conductive type, and A Second iNsuLatioN filM; a first coNduCtive tYpe OF a singLe crysTal siLiCon GERmaniUM LaYer PrOvided in thE OPenIng; a sEcOnd cOnductiVe type of a single crySTal Silicon germanIum LayeR PRoVidED oN The FiRSt cONDuctive type of thE single cryStAL sIlicon germANiuM lAyer; and A second ConduCTive typE of a poly-cRystal silIcOn geRMAniUm layer plaCed in conTact with bOTh the SEcOnd coNduCtive tYpE of The siNgle crYStaL siliCon gerMaNium laYer anD tHe second Conductive type of the poly-CrystaL layeR.
MoReover, JapAneSE PuBlication pateNt ApplicatIon (jP-B2-heiseI, 07-44185) diSCloseS the FOlLowINg semIconDUctor deviCE. THe sEMIcOnductor devICE Is a BipolAr tRAnsistOr, in Which on a silicon suBStrate or a silicOn epITAxiAl lAYer hAvIng a first conduCtiVe TYPe, has a coMpOund crystal Layer comPoSEd of sIlicon And gerManium, aND HaS A seconD conDucTive type iMpuRiTY layer iN tHe COmpounD cryStAl, and hAs a silICon lAYEr having a first coNductIVE type IMpuRity oN tHe
 emitter side towards thecollectorsideand  aco ncen trat ion of the sec o nd c onductive type impurit y isgr a dual l yreduc ed from th e emi tt er  si de to wards  th e colle ctor side. 
Ja pa nese Laid Op e nPatent App lic ation (JP-A- Hei sei, 1 1- 214 3 99) d isc loses  the f o llowin g bipolar  s e micond u ctor de v i ce . Th e bipolar semicon d uc t or device is p rovide dw it h :  asem iconductor  l ayerh aving a fi r s t  co n ductive typeof a buried lay er soas  to form a  coll ec t orregion, ona su bstrate;a firs t  insula t ion fil m form edonthes em ic ond uc t orl ay er; a s econd co nd uc tivetype o f a fi rst  con ducti ve film simil arl y fo r med  on t he se mico nd uctor  layer  so a sto form a baseregi on, a sec ond  c ond uc tivet ype of  asec ond con ductive fil mw h i ch  is formed on thefi r s tinsulati on fil m  a nd connecte dtothef i rst c ondu c ti ve filmso ast ofo rm a ba se  pull- ou t e lec trode ;  and  a fir st condu ctive type of a thir d  conductive f i lm w hi c h is  se parated thr ough a se cond in sul a tionfilmfr o mt he second conductiv efilm a nd fo rmed on the f irst condu c t i ve filmso a s  t o  form an emitt er re gion, wher e in the f irstinsulati on film a n d  the sec ond  co ndu cti v e  f ilm are coate d with  g lass ma ter ial ins ula tio n f ilm ,and the s urface o fth egl ass  mate r ial insu la tio nfil m isf lat.
J apane se L ai dO pen  Patent Ap p l icat io n(JP- A-H ei sei,10-7 9 394 ) discl oses thefol l owin gbi polar t ransistor. Th ebipolar tr an sis tor at l east con tains: a first conducti v e typeofa sin glecrystal s ili con la yer ;  a man y-laye r fil mcom p o sed o f afir st  insulatio n fil m hav in g an  openin g provided on a su r fac e of the firs t c ondu c t iv e t y pe ofth e  si n g le crystal sili con layer,  a se cond condu c tiv etype of  a poly -crys t al laye r of a co nductivety pe o p p osi te to thefirst co nductivet ype,a nd  a se con d insu la tio n fil m; a f i rst  cond uctive  t ype of  a si ng le cryst al silicon germanium la yer pr ovide d i n the ope nin g ; a  second c ondu ctive type  of  asingl e c r ystal  sil i co n g e rmani um l a yer provi d ed  on t he  first cond u c t ive  type  of the si ngle  crystal silicong ermanium layer ; an d a s eco n d co nd uctive type of  apo l y -crystal  s ilicon germ anium la ye r  plac ed incontac t withb o th the se cond  co nductivetyp eo f the s in gl e  cryst al s il icon g ermani u m la y e r and the second  cond u c tivet ype  of t he  poly-c r ysta l layer.
M oreover, Ja panese  Pub licat ion Pat en t Appl ica ti on (JP-B2- H eisei, 07 -4418 5) disc lo sesthe  follo wing s emico nduc to r d evice. Th e se m ic on d uct or d evice  i s abipolar t r ansistor , i n  whichon  as i licons ub s t rate or asil icone p itaxial la y er h a vi n g a f irst c onduct ive typ e , h as  a comp oun d crystal l ayer comp o sed  o f si licon an dgerm an ium ,and has a secon d conduc tive typ e impuri tyl ayer in the  c ompound crys tal,an d  has as i lic on laye r  ha vin g a  fir stcond u ctive type impurity on t he
 emitter_side towards_the collector side and_a concentration_of_the second_conductive_type impurity is_gradually reduced from_the emitter side towards_the collector side.
Japanese_Laid_Open Patent Application (JP-A-Heisei, 11-214399) discloses the following bipolar semiconductor device. The bipolar semiconductor_device_is provided_with:_a_semiconductor layer having a first_conductive type of a buried_layer so_as to form a collector region, on a_substrate;_a first insulation_film formed on the semiconductor layer; a second conductive_type of a first conductive film_similarly formed on_the_semiconductor_layer so as to_form a base region, a second_conductive type of a second conductive_film which is formed on the first_insulation film and connected to the_first conductive film so as_to form_a base pull-out electrode; and_a first conductive_type of_a third conductive_film which is separated through a_second insulation film_from the second conductive film and_formed_on the first_conductive_film_so as_to form an_emitter_region, wherein_the_first insulation film and the second_conductive_film are coated with glass material insulation_film, and the surface_of_the glass material insulation_film is flat.
Japanese Laid Open_Patent Application (JP-A-Heisei, 10-79394) discloses the_following bipolar_transistor. The_bipolar transistor at least contains: a first conductive type of a_single crystal silicon layer; a many-layer_film composed of a_first insulation_film_having an opening_provided_on a_surface of the first conductive type of_the single_crystal silicon layer, a second conductive_type of a poly-crystal_layer_of a conductive type opposite to_the first conductive type, and a_second insulation film; a first_conductive_type_of a single crystal silicon_germanium layer provided in the opening;_a second conductive_type of a single crystal silicon germanium_layer_provided on the first conductive type_of_the single crystal silicon germanium layer;_and_a_second conductive type of a_poly-crystal silicon germanium layer placed in_contact with both the second conductive type of the_single crystal silicon_germanium layer and the second_conductive_type_of the poly-crystal layer.
Moreover, Japanese Publication Patent Application (JP-B2-Heisei, 07-44185)_discloses the_following semiconductor device._The semiconductor device is a bipolar transistor, in which on_a silicon substrate or a silicon epitaxial_layer having a first conductive type, has a compound crystal layer_composed of silicon and germanium, and has a_second conductive type impurity layer in the_compound crystal, and has_a_silicon layer having a first conductive type_impurity_on_the