Abstract:
A multiple anodization technique is described for producing GaAs layers of nonuniform thickness; that is, GaAs layers having substantially rectangular steps or grooves of the type capable of guiding light. The technique includes the following steps: (1) growing a native oxide layer on a major surface of the GaAs layer by submersing the GaAs layer in an anodization bath of concentrated H2O2 having a pH less than 6; (2) removing selected portions of the oxide layer so as to expose the GaAs layer adjacent to the desired step region; and (3) immersing the surface again in an anodization bath of concentrated H2O2 having a pH less than 6. Also described are techniques for growing by liquid phase epitaxy an AlGaAs layer over the resultant GaAs step structure in a manner which alleviates two problems: the formation of deleterious oxides on the GaAs layer and the dissolving of the step configuration while in contact with the AlGaAs growth solution.
Abstract:
A method of fabricating dielectric optical waveguides comprises the steps of: (1) fabricating a single or double heterostructure from the GaAs-AlGaAs system preferably by liquid phase epitaxy or molecular beam epitaxy; (2) forming a native oxide layer on the top surface of the heterostructure by anodization in H2O2; (3) removing a portion of the oxide layer to form a mask and hence to define the waveguide shape in the direction of light propagation; and (4) forming a mesa-like structure with optically flat side walls by etching at a slow rate in Br2-CH3OH. After step (4) two alternative techniques leading to structurally different waveguides may be followed. In one technique, an AlGaAs layer is epitaxially grown over the mesa to form a two dimensional waveguide. In the other technique, the edges of the active region of an AlGaAs double heterostructure are differentially etched in a neutral solution of H2O2. The latter step is particularly useful in the fabrication of active devices because the resulting structure is self-masking, thereby facilitating the formation of electrical contacts.
Abstract translation:制造介质光波导的方法包括以下步骤:(1)优选地通过液相外延或分子束外延从GaAs-AlGaAs系统制造单或双异质结构; (2)通过阳极氧化在H 2 O 2中在异质结构的顶表面上形成天然氧化物层; (3)除去氧化物层的一部分以形成掩模,从而在光传播的方向上限定波导形状; 和(4)通过在Br 2 -CH 3 OH中以缓慢的速率蚀刻形成具有光学平坦侧壁的台面状结构。 在步骤(4)之后,可以遵循导致结构不同的波导的两种替代技术。 在一种技术中,在台面上外延生长AlGaAs层以形成二维波导。 在另一种技术中,AlHAs双异质结构的有源区的边缘在H 2 O 2的中性溶液中进行差分蚀刻。 后一步骤在制造有源器件中特别有用,因为所得到的结构是自掩蔽的,从而有助于电接触的形成。
Abstract:
An electroluminescent PN-junction diode containing isoelectronic traps is fabricated with a relatively high concentration of such traps located within a few diffusion lengths of the PN-junction and a relatively low concentration of such traps farther away from the junction. Thereby, absorption by such traps away from the junction, of radiation emitted at such traps at the junction, is minimized. In particular, a method is described for epitaxially growing such a gallium phosphide PN-junction diode with a higher concentration of isoelectronic nitrogen traps near the junction than elsewhere in the diode.
Abstract:
A method of fabricating dielectric optical waveguides comprises the steps of: (1) fabricating a single or double heterostructure from the GaAs-AlGaAs system preferably by liquid phase epitaxy or molecular beam epitaxy; (2) forming a native oxide layer on the top surface of the heterostructure by anodization in H2O2; (3) removing a portion of the oxide layer to form a mask and hence to define the waveguide shape in the direction of light propagation; and (4) forming a mesa-like structure with optically flat side walls by etching at a slow rate in Br2-CH3OH. After step (4) two alternative techniques leading to structurally different waveguides may be followed. In one technique, an AlGaAs layer is epitaxially grown over the mesa to form a two dimensional waveguide. In the other technique, the edges of the active region of an AlGaAs double heterostructure are differentially etched in a neutral solution of H2O2. The latter step is particularly useful in the fabrication of active devices because the resulting structure is self-masking, thereby facilitating the formation of electrical contacts.
Abstract translation:制造介质光波导的方法包括以下步骤:(1)优选地通过液相外延或分子束外延从GaAs-AlGaAs系统制造单或双异质结构; (2)通过阳极氧化在H 2 O 2中在异质结构的顶表面上形成天然氧化物层; (3)除去氧化物层的一部分以形成掩模,从而在光传播的方向上限定波导形状; 和(4)通过在Br 2 -CH 3 OH中以缓慢的速率蚀刻形成具有光学平坦侧壁的台面状结构。 在步骤(4)之后,可以遵循导致结构不同的波导的两种替代技术。 在一种技术中,在台面上外延生长AlGaAs层以形成二维波导。 在另一种技术中,AlHAs双异质结构的有源区的边缘在H 2 O 2的中性溶液中进行差分蚀刻。 后一步骤在制造有源器件中特别有用,因为所得到的结构是自掩蔽的,从而有助于电接触的形成。
Abstract:
An electroluminescent PN junction gallium phosphide diode is fabricated with the P-type zone rich in zinc oxygen pairs and the N-type zone rich in isoelectronic nitrogen. In this diode, the apparent color of the emitted light can be controlled by varying the electrical current in the diode, from the red through the yellow to the green portions of the color spectrum. Thereby, an electroluminescent diode device is afforded, having a threefold (or more) positive standby signal characteristic.