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New Technology Presentation Meetings! -Life science field- (February 1st)


New Technology Presentation Meetings! -Life science field-
μ-LED with RGB dots integration is realized by use of control of Nano size column

February 1st, 2019, “New Technology Presentation Meetings! -Life science field-” was held in JST (Tokyo). In this here, an oral presentation of Professor. Kishino (Sophia University) is picked up.

Recently, μ-LED is expected to be a next-generation display. However, there are problems for practical use. One is its luminous efficiency. Concretely, luminous efficiency of Green and Red InGaN series LEDs are smaller than that of blue LED. Another is extremely low productivity. In pilot-producing, firstly each color LED sheets are manufactured respectively, and then, individual chip is cut from its substrate, and finally, its chips are mounted to a display substrate respectively and regularly by the pick and place method using robots at the present moment. For this reason, manufactured μ-LED by this method is not competitive against competing products, such as TFT-LCD and OLED. Therefore, the research group has developed a new manufacturing technology in order to solve these problems.


Picture 1. Diameter of GaN Nano size column and its emission1)
In this new technology, InGaN Nano size column with regularly fine pattern is used as a masking tool. It's possible to control emission color by diameter of Nano size column. Concretely, first of all, Ti film on the base substrate is patterned by EB exposure + ICP dry-etching, as a result, a masking pattern is formed in the substrate. The next, InGaN series LEDs grow on Nano size column pattern selectively by RF plasma electron beam epitaxy method.

Picture 1 shows emission of pilot-produced samples. If diameter of Nano size column is 143 nm, 159nm, 175nm, 196nm, 237nm, and 270nm, blue, blue green, green, yellow, orange, and red emissions are obtained respectively. In short, wavelength can be controlled in all invisible region. Of course, 3 wavelength display can be manufactured easily by forming RGB sub-pixels regularly at the same time. For this reason, manufacturing cost is expected to be drastically reduced.

Reference
1)Kishino：Batch integration technology of three primary colors LED for μ-LED display, New Technology Presentation Meetings! -Life science field-, pp.3-6 (2019.2)
※This title is translated arbitrarily by Stella News Site because of without English edition of presentation material.

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