Semiconductor display, optoelectronic semiconductor component and method for the production thereof
A semiconductor display may include a multiplicity of semiconductor pillars as well as first contact strips and second electrical contact strips. The semiconductor pillars each comprise a semiconductor core of a first conductivity type and a semiconductor shell of a second conductivity type different from the first conductivity type, as well as an active layer between them for radiation generation. The semiconductor pillars each comprise an energization shell which is applied onto the respective semiconductor shell for energization. The semiconductor pillars can be electrically driven independently of one another individually or in small groups by means of the first and second electrical contact strips.
1. A semiconductor display comprising:
a multiplicity of semiconductor pillars, and
first electrical contact strips and second electrical contact strips, and
at least one casting body that is opaque for the radiation to be generated,
wherein
each of the multiplicity of the semiconductor pillars comprises a semiconductor core of a first conductivity type and a semiconductor shell of a second conductivity type different from the first conductivity type, as well as an active layer between the semiconductor core and the semiconductor shell for radiation generation,
each of the multiplicity of semiconductor pillars comprises an energization shell applied onto the respective semiconductor shell for energization, and
the multiplicity of semiconductor pillars or small groups of semiconductor pillars can be driven independently of one another by means of the first contact strips and the second electrical contact strips,
and each of the small groups comprises at most 25 of the semiconductor pillars, and
at least 10 4 of the multiplicity of the semiconductor pillars and are located in recesses of the casting body.
2. The semiconductor display as claimed in claim 1 , wherein
at least 10 6 of the multiplicity of semiconductor pillars are applied in the recesses of the casting body,
an average diameter of the multiplicity of semiconductor pillars ranges from 40 nm to 5 μm inclusive,
a ratio of an average height of the semiconductor pillars and the average diameter ranges from 0.5 to 3 inclusive,
the multiplicity of semiconductor pillars are hexagonal and are grown from a base region and comprise a pyramidal tip opposite the base region,
the active layer extends continuously over side surfaces and the tip,
the first contact strips extend perpendicularly to the second contact strips as seen in plan view, and
each of the small groups of the multiplicity of semiconductor pillars comprises at most 16 of the semiconductor pillars.
3. The semiconductor display as claimed in claim 1 ,
wherein the radiation generated during operation leaves the multiplicity of semiconductor pillars only through the base region in the direction away from the tips.
4. The semiconductor display as claimed in claim 1 ,
wherein the semiconductor pillars protrude from the casting body on two mutually opposite main sides of the casting body.
5. The semiconductor display as claimed in claim 1 ,
wherein the first contact strips extend along rows at the tips, and the multiplicity of semiconductor pillars are electrically contacted at least at the tips.
6. The semiconductor display as claimed in claim 1 ,
wherein the recesses have a different base shape than the multiplicity of semiconductor pillars, as seen in cross section.
7. The semiconductor display as claimed in claim 1 ,
wherein the second contact strips comprise an n-conductive semiconductor layer, from which the multiplicity of semiconductor pillars are grown, the second contact strips being configured as column contacts.
8. The semiconductor display as claimed in claim 7 ,
wherein at least one mirror for reflection of the radiation generated during operation is applied on a side of the n-conductive semiconductor layer facing away from the multiplicity of semiconductor pillars,
an electrical through-contact in the direction away from the multiplicity of semiconductor pillars being applied on at least one of the mirrors.
9. The semiconductor display as claimed in claim 1 ,
further comprising a mask layer having a multiplicity of openings,
each of the multiplicity of semiconductor pillars being grown from a respective opening and the openings each being fully covered by the semiconductor pillars, and
the mask layer being made of an inorganic material and forming a continuous layer with a thickness of at most 10 nm.
10. The semiconductor display as claimed in claim 1 ,
wherein the second contact strips comprise at least one transparent conductive layer,
the first contact strips being configured to be reflective for the radiation to be generated and the energization shells being contained by the first contact strips.
11. The semiconductor display as claimed in claim 10 ,
wherein the second contact strips additionally comprise at least one metal busbar,
the semiconductor pillars being located along a principal emission direction respectively between the electrically assigned transparent conductive layer and the assigned busbar, and
the busbar being freely accessible.
12. The semiconductor display as claimed in claim 1 ,
wherein the multiplicity of semiconductor pillars are located on a growth substrate,
the first contact strips and the second contact strips being applied on the same side of the growth substrate as the multiplicity of semiconductor pillars.
13. The semiconductor display as claimed in claim 1 ,
further comprising electrical contact pads for external electrical contacting of the first contact strips and the second contact strips, the contact pads being located next to an emission field formed by the multiplicity of semiconductor pillars as seen in plan view, and
all the contact pads being applied on the same side of the multiplicity of semiconductor pillars, so that the semiconductor display is surface-mountable.
14. The semiconductor display as claimed in claim 13 ,
wherein the electrical contact pads have a greater width than the associated first contact strips and/or second contact strips as seen in plan view.
15. The semiconductor display as claimed in claim 1 ,
wherein the recesses are configured with the same shape as the semiconductor pillars, and the recesses are filled to at least 70% by the multiplicity of semiconductor pillars,
the casting body directly adjoining the energization shells in places.
16. A production method for a semiconductor display as claimed in claim 1 , wherein the method comprises:
growing the multiplicity of semiconductor pillars on a growth substrate from the openings of the mask layer,
applying the energization shells on the semiconductor pillars,
producing the first contact strips and the second electrical contact strips, and
forming the display and/or to forming the semiconductor components.
17. The method as claimed in claim 16 ,
further comprising
providing a carrier and transferring only a part of the semiconductor pillars originally grown on the growth substrate onto the carrier, so that an average distance of the multiplicity of semiconductor pillars from one another on the carrier is greater at least by a factor of 2 than on the growth substrate.
18. The method as claimed in claim 17 ,
further comprising:
introducing the semiconductor pillars into a transfer matrix, then
solidifying the transfer matrix around some of the semiconductor pillars, then
detaching only the semiconductor pillars with the solidified transfer matrix from the growth substrate ( 20 ), and then removing the transfer matrix.
19. The method as claimed in claim 16 ,
wherein the multiplicity of semiconductor pillars are grown directly on the mask layer with a smaller diameter than further away from the mask layer and the growth substrate, so that intended fracture positions for detachment of the semiconductor pillars from the growth substrate are formed on the mask layer.