臺灣博碩士論文加值系統

本論文係利用紅外線爐化學氣相沉積的方式將硒化鋅異質磊晶
於矽基板上,並採用兩階段長晶法克服兩者4.1%的晶格不匹配。磊晶 成
長完之硒化鋅薄膜分別藉由SEM, SIMS, XRD 和PL 加以探討,吾 人觀
察得知硒化鋅薄膜之表面平滑,硒和鋅成份分佈均勻而且薄膜結 構接近
單晶。 由PL
光譜在10K時測得硒化鋅薄膜在444nm(2.793eV)有一能隙 光造成
的NBE peak。隨著溫度的升高NBE peak強度減小,線寬變寬 並且波峰
往長波長偏移。而經銦摻雜的硒化鋅薄膜在452nm(2.743eV) 有一施體階
造成的peak。 在元件的
製作方面,吾人利用此硒化鋅異質磊晶層製作蕭特基二 極體及異質
接面雙極性電晶體。在蕭特基二極體方面,吾人嘗試改變 各種蕭特基金
屬,藉由I-V和C-V方式量測硒化鋅磊晶層之濃度以及 其位障高。而在
蕭特基光二極體方面,發現在短波長450nm時具有最 大光電流響應。

在 self-aligned ZnSe/Si 異質接面雙極性電晶體方面,測得元件之 共
射極電流增益為28。而異質光電晶體特性方面,在短波長470nm藍 光波
段時亦具有最大光電流響應。由結果得知將硒化鋅成長於矽基板 所製作
之光電元件極適合來製作低成本的短波長藍光偵測器,在未來 短波長元
件的OEIC應用上極具潛力。

In this thesis, the ZnSe epilayers were grown on an
oriented-(111) Si substrate by using IR furnace CVD system
and two-step growth process to overcome the approximately
4.1% lattice mismatch between ZnSe and Si substrate. The
ZnSe epilayer were analyzed by using SEM, SIMS, XRD,
and PL measurements. The surface morphology of the ZnSe epilayer
is smooth, the distribution of the main elements are
uniformity and the ZnSe epilayer approaches to a single
crystal. From the PL
measurement at 10K for the ZnSe epilayer, it indicates
the NBE excitation emission is at 444nm(2.793eV). With the
increasing of the temperature, the intensities of the NBE
peak decrease and the FWHM becomes broader. Then it shifts
toward longer wavelengths region. For the In-doped ZnSe
epilayer, we observe the D1 peak is at 452nm due to the
In replace the Zn site induce the transition between a shallow
donor and the valence band level.

The optimum ZnSe epilayers can be achieved successfully to
fabricate the devices of the Schottky barrier diodes and
heterojunction bipolar transistor. The carrier
concentration of the ZnSe epilayer and the barrier heights of
the ZnSe/Si Schottky barrier diodes with various Schottky
metals were estimated by the I-V and C-V measurement. In
addition, the Au-ZnSe/Si Schottky photodiode exhibits
strong responsivity in 450nm. The common-emitter
current gain for the novel structure of self-
aligned ZnSe/Si HBT is high about 28. And the ZnSe/Si
heterojunction photo-transistor also reveals the strong
photo-responsivity in 470nm. It demonstrated the studying of
photodetectors based on ZnSe grown on Si substrate are
useful to develop low cost short wavelength blue light opto-
electronic devices and have a great potential for the
applications of the short wavelength OEIC.