JPH03284831A - Forming method for semiconductor thin-film - Google Patents
Forming method for semiconductor thin-filmInfo
- Publication number
- JPH03284831A JPH03284831A JP8598690A JP8598690A JPH03284831A JP H03284831 A JPH03284831 A JP H03284831A JP 8598690 A JP8598690 A JP 8598690A JP 8598690 A JP8598690 A JP 8598690A JP H03284831 A JPH03284831 A JP H03284831A
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor thin
- film
- thin film
- laser
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 93
- 239000010409 thin film Substances 0.000 title claims abstract description 90
- 238000000034 method Methods 0.000 title claims description 19
- 239000010408 film Substances 0.000 claims abstract description 36
- 239000000758 substrate Substances 0.000 claims abstract description 24
- 230000001678 irradiating effect Effects 0.000 claims description 8
- 239000010410 layer Substances 0.000 abstract description 17
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 abstract description 10
- 229910052786 argon Inorganic materials 0.000 abstract description 5
- 238000010438 heat treatment Methods 0.000 abstract description 3
- 239000002344 surface layer Substances 0.000 abstract description 3
- 230000008018 melting Effects 0.000 abstract description 2
- 238000002844 melting Methods 0.000 abstract description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 15
- 239000011521 glass Substances 0.000 description 8
- 239000012535 impurity Substances 0.000 description 7
- 238000002230 thermal chemical vapour deposition Methods 0.000 description 7
- 125000004430 oxygen atom Chemical group O* 0.000 description 6
- 125000004429 atom Chemical group 0.000 description 5
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 5
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000009291 secondary effect Effects 0.000 description 1
Landscapes
- Thin Film Transistor (AREA)
- Recrystallisation Techniques (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は半導体薄膜の形成方法に関し、特に半導体薄膜
を結晶化させた後に、再びレーザ光を照射して半導体薄
膜を加熱する半導体薄膜の形成方法に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for forming a semiconductor thin film, and in particular to a method for forming a semiconductor thin film, in which the semiconductor thin film is crystallized and then heated by irradiating the semiconductor thin film again with laser light. Regarding the method.
（従来の技術）
従来から、ガラスなどの絶縁基板上に酸化シリコン（Ｓ
ｉＯ２）などから成る熱！！衝膜と非晶質若しくは多結
晶の半導体薄膜とを形成して、この半導体薄膜に連続発
振アルゴンレーザなどを照射して、半導体薄膜を溶融・
固化させることにより半導体薄膜を結晶化させる半導体
薄膜の結晶化法があった。(Prior art) Silicon oxide (S) has traditionally been deposited on an insulating substrate such as glass.
Heat consisting of iO2) and more! ! A bombardment film and an amorphous or polycrystalline semiconductor thin film are formed, and this semiconductor thin film is irradiated with a continuous wave argon laser or the like to melt and melt the semiconductor thin film.
There is a crystallization method for semiconductor thin films that crystallizes semiconductor thin films by solidifying them.
（発明が解決しようとする問題点）
ところが、この従来の半導体薄膜の結晶化法では、半導
体薄膜にレーザ光を照射して半導体薄膜を溶融させた際
に、酸化シリコンなどから成る熱緩衝膜も加熱され、結
晶化した後の半導体薄膜に酸素原子が多数取り込まれて
しまうという問題があった０例えば、通常の単結晶シリ
コン基板では酸素原子は１０１′１個／ｃｍ’程度しか
存在しないのに対して、上述のような構成を有する半導
体薄膜をレーザ光で結晶化した場合、シリコン膜中には
、１０１９〜１０２０個／ｃｍ’程度酸素原子が存在し
ている。このような半導体薄膜でトランジスタを形成す
ると、過飽和の酸素原子が数個集合してクラスターとな
り、これがドナーを形成してしまう、イオン化したドナ
ーは、キャリアの散乱中心となるため、半導体膜中での
電子および正孔の移動度に悪影響を与える。したがって
、半導体特性を改善するには、上述のようなサーマルド
ナーを消滅させることが有効である。(Problems to be Solved by the Invention) However, in this conventional method for crystallizing semiconductor thin films, when the semiconductor thin film is irradiated with laser light to melt the semiconductor thin film, the thermal buffer film made of silicon oxide etc. There was a problem that a large number of oxygen atoms were incorporated into the semiconductor thin film after it was heated and crystallized.For example, in a normal single crystal silicon substrate, there are only about 101'1 oxygen atoms/cm'. On the other hand, when a semiconductor thin film having the above-mentioned structure is crystallized by laser light, approximately 1019 to 1020 oxygen atoms/cm' exist in the silicon film. When a transistor is formed using such a semiconductor thin film, several supersaturated oxygen atoms gather together to form a cluster, which forms a donor.The ionized donor becomes a scattering center for carriers, so it becomes a cluster in the semiconductor film. Adversely affects electron and hole mobility. Therefore, in order to improve semiconductor characteristics, it is effective to eliminate the thermal donors as described above.
単結晶のシリコン基板を用いた半導体製造プロセスでは
、酸化膜の形成工程や不純物の拡散工程など１０００℃
以上の高温工程があるため、サーマルドナーは分解して
しまうが、ガラス基板上に薄膜トランジスタを形成する
場合、高温プロセスがないため、最後までサーマルドナ
ーが残ってしまい、応答速度の速いトランジスタを得る
ことができないという問題があった。また、８００℃で
１０秒程度のＲＴＰ （ランプアニール法によるラビッ
ドサーマルプロセス）も有効であるが、ガラス基板をこ
のような高温の炉の中に入れることはできない。In the semiconductor manufacturing process using single-crystal silicon substrates, temperatures such as oxide film formation and impurity diffusion processes are heated to 1000°C.
Due to the above high-temperature process, the thermal donor decomposes, but when forming a thin film transistor on a glass substrate, there is no high-temperature process, so the thermal donor remains until the end, making it difficult to obtain a transistor with a fast response speed. The problem was that it was not possible. Further, RTP (Rapid Thermal Process by Lamp Annealing) at 800° C. for about 10 seconds is also effective, but the glass substrate cannot be placed in such a high-temperature furnace.
本発明は、このような問題点に鑑みて案出されたもので
あり、結晶化した半導体薄膜中のサーマルドナーを分解
して消滅させることにより、電子および正孔の移動度の
速いトランジスタを得ることができる半導体薄膜を形成
することを目的とするものである。The present invention was devised in view of these problems, and aims to obtain a transistor with high electron and hole mobility by decomposing and eliminating thermal donors in a crystallized semiconductor thin film. The purpose of this is to form a semiconductor thin film that can be used.
（問題点を解決するための手段）
本発明によれば、基板上に第１の絶縁膜と非晶質若し゛
くは多結晶の半導体薄膜とを形成してレーザ光を照射す
ることにより半導体薄膜を溶融・固化させて結晶化させ
る半導体薄膜の形成方法において、前記半導体薄膜を結
晶化させた後、さらに前記レーザ光よりも小エネルギー
のレーザ光を前記半導体薄膜に照射することを特徴とす
る半導体薄膜の形成方法が提供され、そのことにより上
記目的が達成される。(Means for Solving the Problems) According to the present invention, a first insulating film and an amorphous or polycrystalline semiconductor thin film are formed on a substrate, and a semiconductor film is formed by irradiating laser light. The method for forming a semiconductor thin film in which the thin film is melted and solidified to crystallize the semiconductor thin film is characterized in that after the semiconductor thin film is crystallized, the semiconductor thin film is further irradiated with a laser beam having lower energy than the laser beam. A method of forming a semiconductor thin film is provided, thereby achieving the above objects.
（作用）
上記のように構成することにより、結晶化した半導体薄
膜中のサーマルドナーは著しく減少する。(Function) By configuring as described above, the number of thermal donors in the crystallized semiconductor thin film is significantly reduced.
（実施例） 以下、本発明を添付図面に基づき詳細に説明する。(Example) Hereinafter, the present invention will be explained in detail based on the accompanying drawings.
第１図は、本発明をスタガー型の薄膜トランジスタに適
用した例を示す断面図であり、■は＃７０５９基板など
から成るガラス基板、２は酸化シリコン（ＳｉＯ２）な
どから成る絶縁膜である。FIG. 1 is a cross-sectional view showing an example in which the present invention is applied to a staggered thin film transistor, where 2 is a glass substrate made of a #7059 substrate or the like, and 2 is an insulating film made of silicon oxide (SiO2) or the like.
この絶縁膜２は、プラズマＣＶＤ法、熱ＣＶＤ法、光Ｃ
ＶＤ法などで厚み５０００人程度に形成される。この絶
縁膜２は、ガラス基板１と後述する半導体薄膜３とのｐ
！！、膨張の相違を吸収する緩衝膜として、また基板１
から半導体薄膜３に不純物が混入するのを防止するため
に設けられる。This insulating film 2 can be formed by plasma CVD, thermal CVD, photoC
It is formed to a thickness of about 5,000 layers using the VD method. This insulating film 2 is formed between the glass substrate 1 and a semiconductor thin film 3 to be described later.
! ! , as a buffer film to absorb differences in expansion, and also as a substrate 1
This is provided to prevent impurities from being mixed into the semiconductor thin film 3.
前記絶縁膜２上には、第１の半導体薄膜３が設けられる
。この第１の半導体薄膜３は、非晶質若しくは多結晶の
半導体薄膜で構成され、プラズマＣＶＤ法、熱ＣＶＤ法
、光ＣＶＤ法などで厚み５０００λ程度に形成される。A first semiconductor thin film 3 is provided on the insulating film 2 . This first semiconductor thin film 3 is composed of an amorphous or polycrystalline semiconductor thin film, and is formed to a thickness of about 5000λ by plasma CVD, thermal CVD, photoCVD, or the like.
この第１の半導体薄膜３を形成する際に、同時にボロン
やリンなどの不純物原子を１０′５〜１０１８個／ ｃ
ｍ ’程度あらかじめ含有させて置く。When forming this first semiconductor thin film 3, impurity atoms such as boron and phosphorus are simultaneously added at 10'5 to 1018 atoms/c.
m' in advance.
前記第１の半導体膜Ｍ３に基板１側から若しくは半導体
薄膜３側からレーザ光を照射して結晶化させる。レーザ
光としては、例えば０．１〜２゜Ｗの出力でスポット径
が１００μｍ程度の連続波アルゴンレーザなどが好適に
用いられ、走査速度０５〜２０ｃｍ／ｓｅｃ程度で走査
される。このようにして結晶化させた第１の半導体薄膜
には、サーマルドナーとなる酸素原子を１０１９〜１０
２０個／ｃｍ’程度含有している。The first semiconductor film M3 is irradiated with laser light from the substrate 1 side or from the semiconductor thin film 3 side to crystallize it. As the laser light, for example, a continuous wave argon laser with an output of 0.1 to 2 degrees W and a spot diameter of about 100 μm is preferably used, and the laser beam is scanned at a scanning speed of about 05 to 20 cm/sec. The first semiconductor thin film crystallized in this manner contains 1019 to 10 oxygen atoms, which serve as thermal donors.
It contains about 20 pieces/cm'.
次に、第１の半導体薄膜３上に、逆導電型となる不純物
原子を含有する非晶質若しくは多結晶の第２の半導体薄
膜４ａ、４ｂを形成する。この第２の半導体膜Ｍ４ａ、
４ｂ部分は、ソース領域とドレイン領域となり、プラズ
マＣＶＤ法、熱ｃＶＤ法、或いは光ＣＶＤ法などで厚み
５００人程度に形成される。Next, amorphous or polycrystalline second semiconductor thin films 4a and 4b containing impurity atoms of opposite conductivity type are formed on the first semiconductor thin film 3. This second semiconductor film M4a,
The portion 4b becomes a source region and a drain region, and is formed to a thickness of approximately 500 mm using a plasma CVD method, a thermal CVD method, a photo CVD method, or the like.
前記第１の半導体薄膜３上の第２の半導体薄膜４ａと４
ｂとの間には、酸化シリコン（ＳｉＯ２）などから成る
ゲート絶縁Ｍ５が厚み１０００人程度に形成される。Second semiconductor thin films 4a and 4 on the first semiconductor thin film 3
A gate insulator M5 made of silicon oxide (SiO2) or the like is formed to a thickness of about 1000 mm between the gate electrode and the gate electrode b.
次に、基板１側がらレーザ光を照射して、第１の半導体
薄膜３を加熱する。このレーザ光としては、１〜２Ｊ／
ｃｍ２程度のエキシマレーザが好適に用いられる。すな
わち、エキシマレーザは短波長光であるため、半導体薄
膜３の極表面層のみで吸収される程度となるが、サーマ
ルドナーは分解され、電子および正孔の移動度は向上す
る。また、第２の半導体層４ａ、４ｂの第１の半導体層
３との接合部近傍が熱アニールされることによって接合
特性が改善されるとともに、ゲート絶縁膜５と第１の半
導体層３との界面準位も低下する。Next, the first semiconductor thin film 3 is heated by irradiating laser light from the substrate 1 side. This laser light is 1 to 2 J/
An excimer laser of about cm2 is preferably used. That is, since the excimer laser is a short wavelength light, it is absorbed only in the extreme surface layer of the semiconductor thin film 3, but the thermal donor is decomposed and the mobility of electrons and holes is improved. Further, by thermally annealing the vicinity of the junction between the second semiconductor layers 4a and 4b and the first semiconductor layer 3, the junction characteristics are improved, and the junction between the gate insulating film 5 and the first semiconductor layer 3 is improved. The interface level also decreases.
また、半導体層４側からエキシマレーザを導入すれば、
サーマルドナーの解消とともに接合部近傍が溶融・結晶
化し、ホモのｐ−ｎ接合となって接合特性がさらに改善
されるという副次的効果もある。なお、エキシマレーザ
の代わりに、低パワーのアルゴンレーザなどを用いても
よい。Moreover, if an excimer laser is introduced from the semiconductor layer 4 side,
As the thermal donor is eliminated, the vicinity of the junction melts and crystallizes, forming a homogeneous p-n junction, which further improves the junction characteristics, which is a secondary effect. Note that a low power argon laser or the like may be used instead of the excimer laser.
最後に、ゲート絶縁膜５上、ソース領域４ａ上、および
ドレイン領域４ｂ上にそれぞれＡＩ＝Ｔａ、Ｗ、Ｔｉ、
Ｎｉ＝ Ｍｏ、Ｃｒなどから成る電極６ａ、６ｂ、６ｃ
を真空蒸着法やスパッタリング法などで形成してスタガ
ー型の薄膜トランジスタが完成する。Finally, AI=Ta, W, Ti,
Ni = electrodes 6a, 6b, 6c made of Mo, Cr, etc.
A staggered thin film transistor is completed by forming the thin film transistor using a vacuum evaporation method or a sputtering method.
第２図は、本発明を逆スタガー型の薄膜トランジスタに
適用した例を示す断面図であり、１１は＃７０５９基板
などから成るガラス基板、１２は酸化シリコン（Ｓ ｌ
０２ ）などから成る第１の絶縁膜である。FIG. 2 is a cross-sectional view showing an example in which the present invention is applied to an inverted stagger type thin film transistor, in which 11 is a glass substrate made of #7059 substrate, etc., 12 is a silicon oxide (Sl
02) or the like.
この第１の絶縁膜１２は、プラズマＣＶＤ法、熱ＣＶＤ
法、光ＣＶＤ法などで厚み５０００人程度ロス成される
。この第１の絶縁膜１２は、ガラス基板１１と後述する
半導体薄膜１３との熱膨張の相違を吸収する緩衝膜とし
て、また基板１１がら半導体薄膜１３に不純物が混入す
るのを防止するために設けられる。This first insulating film 12 is formed by plasma CVD method, thermal CVD method,
A loss of about 5,000 layers is achieved using the optical CVD method. This first insulating film 12 is provided as a buffer film to absorb the difference in thermal expansion between the glass substrate 11 and a semiconductor thin film 13, which will be described later, and to prevent impurities from being mixed into the semiconductor thin film 13 from the substrate 11. It will be done.
前記第１の絶縁膜１２上には、Ｔａ、Ｗ、Ｔｉ、Ｎｉ、
Ｍｏ−Ｃｒなどから成るゲート電極１６ｃが厚み３００
０人程度ロスパッタリング法や真空蒸着法により形成さ
れる。On the first insulating film 12, Ta, W, Ti, Ni,
The gate electrode 16c made of Mo-Cr or the like has a thickness of 300 mm.
It is formed by a loss sputtering method or a vacuum evaporation method.
前記ゲート電極１６ｃと第１の絶縁膜１２上には、ゲー
ト絶縁膜１５が形成される。このゲート絶縁膜１５は、
酸化シリコン（ＳｉＯｚ）などがち成り、プラズマＣＶ
Ｄ法、熱ＣＶＤ法、光ＣＶＤ法などで厚み１０００人程
度１形成される。A gate insulating film 15 is formed on the gate electrode 16c and the first insulating film 12. This gate insulating film 15 is
Silicon oxide (SiOz) etc. are formed, and plasma CV
The film is formed to a thickness of about 1,000 layers using the D method, thermal CVD method, photo-CVD method, etc.
前記ゲート絶縁膜１５上には、第１の半導体薄膜１３が
設けられる。この第１の半導体薄膜１３は、非晶質若し
くは多結晶の半導体薄膜で構成され、ブラズ？ＣＶＤ法
、熱ＣＶＤ法、光ＣＶＤ法などで厚み５０００人程度ロ
ス成される。この第１の半導体薄膜１３を形成する際に
、同時にボロンやリンなどの不純物原子を１０１５〜１
０１８個／ｃｒｎ’程度あらかじめ含有させて置く。A first semiconductor thin film 13 is provided on the gate insulating film 15 . This first semiconductor thin film 13 is composed of an amorphous or polycrystalline semiconductor thin film, and is made of a BLAZ? A loss of about 5,000 layers is achieved by CVD, thermal CVD, photo-CVD, etc. When forming this first semiconductor thin film 13, impurity atoms such as boron and phosphorus are added at the same time to 1015 to 1
Approximately 0.018 pieces/crn' are pre-contained.
前記第１の半導体薄膜１３に基板１１側から若しくは半
導体薄膜１３（！ｌからレーザ光を照射して結晶化させ
る。レーザ光としては、例えば０．１〜２０Ｗの出力で
スポット径が１００μｍ程度の連続波アルゴンレーザな
どが好適に用いられ、走査速度０−５〜２０ｃｍ／ｓｅ
ｃ程度で走査される。このようにして結晶化させた第１
の半導体薄膜１３には、サーマルドナーとなる酸素原子
を１０１ｇ〜１０２０個／Ｃｍ３程度含有している。The first semiconductor thin film 13 is crystallized by irradiating laser light from the substrate 11 side or from the semiconductor thin film 13 (!l).The laser light has a spot diameter of about 100 μm with an output of 0.1 to 20 W, for example. Continuous wave argon laser etc. are preferably used, and the scanning speed is 0-5 to 20 cm/sec.
It is scanned at approximately c. The first crystallized in this way
The semiconductor thin film 13 contains approximately 101 g to 1020 oxygen atoms/Cm3, which serve as thermal donors.
前記第１の半導体薄膜１３上の全面に、酸化シリコン膜
を成膜して、ゲート電極１６ｃをマスクにして酸化シリ
コン膜をエツチング除去し、第１の半導体薄膜１３上の
ゲート電極１６ｃに対応する位置に酸化シリコン膜１７
を形成する。A silicon oxide film is formed on the entire surface of the first semiconductor thin film 13, and the silicon oxide film is etched away using the gate electrode 16c as a mask, so as to correspond to the gate electrode 16c on the first semiconductor thin film 13. Silicon oxide film 17 at position
form.
次に、第１の半導体薄膜１３および酸化シリコン膜１７
上に、逆導電型となる不純物原子を含有する非晶質若し
くは多結晶の第２の半導体薄膜１４をプラズマＣＶＤ法
、熱ＣＶＤ法、或いは光ＣＶＤ法などで厚み５００人程
ロス形成する。この第２の半導体薄膜１４は、後に分割
されてソース領域とドレイン領域となる。Next, the first semiconductor thin film 13 and the silicon oxide film 17 are
A second amorphous or polycrystalline semiconductor thin film 14 containing impurity atoms of the opposite conductivity type is formed thereon by a plasma CVD method, a thermal CVD method, a photo-CVD method, or the like to a thickness of about 500 layers. This second semiconductor thin film 14 is later divided into a source region and a drain region.
次に、第２の半導体薄膜１４上からレーザ光を照射して
、第１の半導体薄膜１３を加熱する。このレニザ光とし
ては、１〜２Ｊ／ｃｍ２程度のエキシマレーザが好適に
用いられる。すなわち、エキシマレーザは短波長光であ
るため、第１の半導体薄膜１３の極表面層のみで吸収さ
れる。このため、レーザ結晶化した第１の半導体薄膜１
３と接触している第２の半導体薄膜１４は溶融して結晶
化し、ホモのｐ−ｎ接合となり、接合特性が改善される
。一方、セルファラインされた酸化シリコン膜１７上の
第２の半導体層１４は溶融して結晶化するが、酸化シリ
コン膜１７で遮蔽されて、レーザ結晶化シリコン１３と
は分離されるものの、熱は伝播する。下部のレーザ結晶
化シリコン１３は溶融には至らないが、熱処理を受ける
ことになり、サーマルドナーを分離消滅させることとな
る。Next, the first semiconductor thin film 13 is heated by irradiating the second semiconductor thin film 14 with laser light. As this laser light, an excimer laser with a power of about 1 to 2 J/cm2 is preferably used. That is, since the excimer laser is short-wavelength light, it is absorbed only by the extreme surface layer of the first semiconductor thin film 13. For this reason, the first semiconductor thin film 1 that has been laser crystallized
The second semiconductor thin film 14 in contact with 3 is melted and crystallized to form a homogeneous p-n junction, improving the junction characteristics. On the other hand, the second semiconductor layer 14 on the self-aligned silicon oxide film 17 melts and crystallizes, but although it is shielded by the silicon oxide film 17 and is separated from the laser-crystallized silicon 13, it does not receive heat. propagate. Although the lower laser crystallized silicon 13 is not melted, it is subjected to heat treatment, and the thermal donor is separated and eliminated.
最後に、第２の半導体層１４上に、アルミニウムなどを
蒸着して、このアルミニウムの所定部分と酸化シリコン
膜１７上の第２の半導体層１４をエツチング除去してソ
ース電極１６ａとドレイン電極１６ｂを形成して完成す
る。Finally, aluminum or the like is deposited on the second semiconductor layer 14, and a predetermined portion of the aluminum and the second semiconductor layer 14 on the silicon oxide film 17 are removed by etching to form the source electrode 16a and the drain electrode 16b. Form and complete.
従来のように、レーザ光で加熱処理をしなかった場合は
、電子の移動度の平均は６０Ｖ−Ｃ／ｃｍ２であったが
、上記実施例のようにパワー１〜２Ｊ／ｃｍ２のエキシ
マレーザを照射して半導体薄膜を加熱処理したところ、
電子の移動度は１００Ｖ−０７ｃｍ２以上になることを
確認した。When heat treatment was not performed with a laser beam as in the past, the average electron mobility was 60 V-C/cm2, but when an excimer laser with a power of 1 to 2 J/cm2 was used as in the above example, When the semiconductor thin film was heat-treated by irradiation,
It was confirmed that the electron mobility was 100V-07cm2 or more.
（発明の効果）
以上のように、本発明に係る半導体薄膜の形成方法によ
れば、半導体薄膜を結晶化させた後、さらにレーザ光を
照射して半導体薄膜を加熱することから、半導体薄膜中
のサーマルドナーを分解して消滅させることができ、応
答速度の速い薄膜トランジスタを形成できる。(Effects of the Invention) As described above, according to the method for forming a semiconductor thin film according to the present invention, after crystallizing the semiconductor thin film, the semiconductor thin film is further heated by irradiating laser light. Thermal donors can be decomposed and eliminated, making it possible to form thin film transistors with fast response speed.
また、レーザ光を照射することによって瞬時的に加熱す
ることから、薄膜半導体を形成する基板としてガラスの
ような比較的低融点の基板を用いることができる。In addition, since it is instantaneously heated by irradiation with laser light, a substrate with a relatively low melting point, such as glass, can be used as a substrate on which a thin film semiconductor is formed.
第１図は本発明に係る半導体薄膜の形成方法をスタガー
型の薄膜トランジスタに適用した例を示す断面図、第２
図は同じく逆スタガー型の薄膜トランジスタに適用した
例を示す断面図である。
１．１１：基板 ２．１２：絶縁膜３．１３ニ一導
電型半導体層
４．１４：逆導電型半導体層
５．１５：ゲート絶縁膜FIG. 1 is a cross-sectional view showing an example in which the method for forming a semiconductor thin film according to the present invention is applied to a staggered thin film transistor;
The figure is a cross-sectional view showing an example in which the present invention is applied to an inverted staggered thin film transistor. 1.11: Substrate 2.12: Insulating film 3.13 Double conductivity type semiconductor layer 4.14: Opposite conductivity type semiconductor layer 5.15: Gate insulating film
Claims (1)
体薄膜とを形成してレーザ光を照射することにより半導
体薄膜を溶融・固化させて結晶化させる半導体薄膜の形
成方法において、前記半導体薄膜を結晶化させた後、さ
らに前記レーザ光よりも小エネルギーのレーザ光を前記
半導体薄膜に照射することを特徴とする半導体薄膜の形
成方法。A method for forming a semiconductor thin film in which a first insulating film and an amorphous or polycrystalline semiconductor thin film are formed on a substrate, and the semiconductor thin film is melted and solidified to crystallize by irradiating the semiconductor thin film with laser light. A method for forming a semiconductor thin film, which comprises crystallizing the thin film and then irradiating the semiconductor thin film with a laser beam having lower energy than the laser beam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8598690A JPH03284831A (en) | 1990-03-30 | 1990-03-30 | Forming method for semiconductor thin-film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8598690A JPH03284831A (en) | 1990-03-30 | 1990-03-30 | Forming method for semiconductor thin-film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03284831A true JPH03284831A (en) | 1991-12-16 |
Family
ID=13874011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8598690A Pending JPH03284831A (en) | 1990-03-30 | 1990-03-30 | Forming method for semiconductor thin-film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03284831A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0786304A (en) * | 1993-06-25 | 1995-03-31 | Semiconductor Energy Lab Co Ltd | Method of manufacturing semiconductor device |
| US6319761B1 (en) | 1993-06-22 | 2001-11-20 | Semiconductor Energy Laboratory Co., Ltd. | Method of fabricating a thin film transistor |
| US6713330B1 (en) | 1993-06-22 | 2004-03-30 | Semiconductor Energy Laboratory Co., Ltd. | Method of fabricating a thin film transistor |
-
1990
- 1990-03-30 JP JP8598690A patent/JPH03284831A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6319761B1 (en) | 1993-06-22 | 2001-11-20 | Semiconductor Energy Laboratory Co., Ltd. | Method of fabricating a thin film transistor |
| US6713330B1 (en) | 1993-06-22 | 2004-03-30 | Semiconductor Energy Laboratory Co., Ltd. | Method of fabricating a thin film transistor |
| JPH0786304A (en) * | 1993-06-25 | 1995-03-31 | Semiconductor Energy Lab Co Ltd | Method of manufacturing semiconductor device |
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