JPS60161396A - Manufacture of silicon thin film - Google Patents

Abstract

PURPOSE:To manufacture a titled silicon thin film having a large area and uniform crystal orientation by depositing polysilicon in an island formed of an insulating material, irradiating a high-output laser in the longitudinal direction of the island, and scanning. CONSTITUTION:The polysilicon 1 is deposited in a recessed island formed on a silicon oxidized film 2 having >=1mu thickness which is formed by the thermal oxidation of a silicon substrate. The silicon oxidized film 2 is heated at >=700 deg.C, and a high-output laser is simultaneously irradiated in the direction as indicated by the arrow 3 for scanning to form a single crystal silicon film having <100> orientation in the vertical direction and <010> orientation in the direction parallel to the groove. The strain of the recrystallized silicon film is reduced, and the generation of cracks is prevented in this way. And the crystal orientattion can be controlled while enlarging the crystal.

Description

【発明の詳細な説明】 本発明は絶縁体上へのシリコン単結晶薄膜製造方法に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a silicon single crystal thin film on an insulator.

近年、３次元回路素子、耐放射線性向上、高速集積回路
等を目的として、絶縁体基板上に単結晶シリコン膜を形
成する試みがなされている。例えば線状ヒータを用いる
方法、電子ビームを用いる方法、レーザビームを用いる
方法が提案され、試みられているが、基板にソリが生ず
る、加熱状態の制御が困難である、チャージアップが生
イ゛る、　。In recent years, attempts have been made to form single-crystal silicon films on insulating substrates for the purpose of three-dimensional circuit elements, improved radiation resistance, high-speed integrated circuits, and the like. For example, a method using a linear heater, a method using an electron beam, and a method using a laser beam have been proposed and tried, but these methods cause warping of the substrate, difficulty in controlling the heating state, and high charge-up. Ru, .

結晶粒界及び結晶方位が制御できない等の難点がある。There are drawbacks such as the inability to control grain boundaries and crystal orientation.

本発明渚は、作成が比較的再現性の良い、レーザビーム
を用いる方法を■−々検討した結果、本発明に到ったも
のである。本発明は、再結晶化したシリコン膜の歪を低
減させてクラック発生を防止し、かつ、結晶粒を増大さ
せつつ結晶方位を制御する方法を与える事を目的とする
。The present invention was developed as a result of extensive research into methods using laser beams that allow for relatively good reproducibility. An object of the present invention is to provide a method of reducing strain in a recrystallized silicon film to prevent cracking and controlling crystal orientation while increasing crystal grains.

本発明は絶縁体で形成された凹状の島内にポリシリコン
を堆積し、全体を７００℃以上の温度に保持した状態で
島の長さ方向に高出力レーザを照射走査し、島内に単結
晶シリコン膜を形成する事を特徴とするシリコン薄膜の
製造方法である。In the present invention, polysilicon is deposited within a concave island formed of an insulator, and while the entire temperature is maintained at a temperature of 700°C or higher, a high-power laser is irradiated and scanned in the length direction of the island, and single crystal silicon is deposited within the island. This is a method of manufacturing a silicon thin film characterized by forming a film.

以下、本発明を実施例を示す図面を用いて具体的に説明
する。第１図は実施例で用いる試料の平面図、第２図は
断面図である。１は通常のＣＶＤ法で堆積したポリシリ
コン島部分、２はシリコン島を凹んでいる厚さ１ミクロ
ン以上のシリコン酸化膜、３はレーザの走査方向を示す
。シリコン酸化膜２はシリコン基板を熱酸化して形成し
た。図にも示されているが、この様なポリシリコン島は
多数、絶縁体上に平行に形成されている。溝平行方向に
レーザ（例えばＡｒレーザ）が走査されるため、この部
分は溶解し垂直方向に＜　ｉｏｏ　＞、溝平行方向に（
０１０）方向をなす傾向を示す。Hereinafter, the present invention will be specifically explained using drawings showing examples. FIG. 1 is a plan view of a sample used in Examples, and FIG. 2 is a cross-sectional view. Reference numeral 1 indicates a polysilicon island portion deposited by an ordinary CVD method, 2 indicates a silicon oxide film having a thickness of 1 micron or more recessing the silicon island, and 3 indicates the laser scanning direction. The silicon oxide film 2 was formed by thermally oxidizing a silicon substrate. As shown in the figure, a large number of such polysilicon islands are formed in parallel on the insulator. Since a laser (for example, an Ar laser) is scanned in the direction parallel to the groove, this part melts and becomes <ioo> in the vertical direction and (in the direction parallel to the groove).
010) Shows a tendency to form a direction.

ランプ加熱により基板全体が７００℃以上になっている
。少なくとも７００℃になっていれば再結晶粒は走査方
向ｉｃ（０１０）方向を、垂直方向に＜　ｉｏｏ　＞方
向配向を促進する。島状構造を酸化シリコン膜で形成し
たのは保温状態を良くし、島全体が単一の結晶とし、半
導体デバイス製造を容易にするためである。酸化シリコ
ン膜が厚い方が保温は良くなるが、歪は増大する傾向を
示す事が従来から認められ、重大な難点となっていた、
が基板を一７００℃以上という高温罠保ちながちレーザ
照射するのでレーザ照射によって再結晶化できるシリコ
ン島の横４を拡大することができ、しかもシリコン唾に
残留する引張歪を減少させ、クランク発生を防止する効
果を本発明者は確認した。The temperature of the entire board is 700°C or higher due to lamp heating. If the temperature is at least 700° C., recrystallized grains promote orientation in the scanning direction ic (010) direction and in the perpendicular direction in the <ioo> direction. The reason why the island-like structure was formed from a silicon oxide film was to improve heat retention, make the entire island a single crystal, and facilitate semiconductor device manufacturing. It has long been recognized that the thicker the silicon oxide film, the better the heat retention, but the tendency for strain to increase, which has been a serious drawback.
Since the substrate is kept at a high temperature of -700°C or higher and irradiated with laser, it is possible to expand the horizontal area of the silicon island that can be recrystallized by laser irradiation, and it also reduces the tensile strain remaining in the silicon saliva, which reduces the occurrence of cranking. The present inventor has confirmed the effect of preventing.

この働きによってシリコン島１の巾を広げることができ
有効なデバイス化面積を広げることができる。レーザの
走査ピッチを適切に選ぶ事によって絶縁体上のシリコン
島は、はとんど完全に単結晶化された。レーザパワーは
大きい方が、あらゆる点でＳｔしいので、硬いキャップ
膜例えば１ｌｌｉｉ３Ｎ。Due to this function, the width of the silicon island 1 can be increased, and the effective device area can be increased. By appropriately selecting the laser scanning pitch, the silicon islands on the insulator were almost completely monocrystalline. The higher the laser power, the better in all respects, so use a hard cap film, for example 1llii3N.

膜を使用する卑は有効である。実旅した例では小島４０
μｍ長さ５００μｍの単結晶シリコン島が得られた。レ
ーザ走査方向の始端となる部分の形状を例えば鎖角端と
する事等により結晶の配向性向上、粒径増大を促進する
事もより有効である。−以上゛に述べたように本発明に
よれば、大面積で結晶方位のそろったシリコン単結晶膜
を製造する上で極めて効果を持っている。なお、本発明
に用いる絶縁体基板は、単結晶Ｓｉ上に形成した５ｉ０
２膜、石英基板、その他が可能であり、特に限定されな
い。なお、実施例でもそうであるように、このＳ　ｉ　
０２膜の厚さは保温の点で１μｍ以上あることが望才し
い。Base using membranes is effective. In the case of actual travel, Kojima 40
Single crystal silicon islands with a length of 500 μm were obtained. It is also more effective to promote improvement in crystal orientation and increase in grain size by, for example, making the shape of the starting end in the laser scanning direction a chain angle end. - As described above, the present invention is extremely effective in producing a silicon single crystal film with a large area and uniform crystal orientation. Note that the insulator substrate used in the present invention is a 5i0 insulator formed on single crystal Si.
Two films, a quartz substrate, and others are possible, and are not particularly limited. Note that, as in the examples, this S i
The thickness of the 02 film is preferably 1 μm or more in terms of heat retention.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図、第２図はそれぞれ本発明の一実施例を示す平面
図、及び断面図であり、図中の１はシリコン島、２はシ
リコン島を囲んでいる絶縁体、３はし／−ザの走査方向
を示す。 ７１−２　図FIG. 1 and FIG. 2 are a plan view and a cross-sectional view, respectively, showing an embodiment of the present invention. In the figures, 1 is a silicon island, 2 is an insulator surrounding the silicon island, and 3 is an insulator/- Indicates the scanning direction of the image. 71-2 Figure

Claims (1)

【特許請求の範囲】[Claims] 絶縁体で形成された凹状の島内にポリシリコンを堆積し
、全体を７００℃以上の温度に保持した状態で、島の長
さ方向に高出力レーザを照射、走介し、島内に単結晶シ
リコン膜を形成する事を特徴とするシリコン薄膜の製造
方法。Polysilicon is deposited inside a concave island made of an insulator, and while the whole is kept at a temperature of 700°C or higher, a high-power laser is irradiated and passed along the length of the island to deposit a single crystal silicon film inside the island. A method for producing a silicon thin film, characterized by forming a silicon thin film.