Method for producing a plurality of semiconductor chips and semiconductor chip

1. A method for producing a plurality of semiconductor chips comprising:

providing a composite assembly, comprising a carrier, a semiconductor layer sequence, and a functional layer;

severing the functional layer by means of coherent radiation along a singulation pattern;

applying a chemical method to the composite assembly along the singulation pattern to form separating trenches in the carrier; and wherein the coherent radiation also melts the composite assembly along the singulation pattern to form a protective layer comprising slag, which delimits the functional layer toward the separating trenches, on at least one side surface of each semiconductor chip to be singulated; wherein at least the functional layer remains covered by the protective layer;

wherein the singulated semiconductor chips each comprise a part of the semiconductor layer sequence, of the carrier and of the functional layer.

2. The method as claimed in claim 1 ,

wherein the functional layer comprises a metallic layer and/or a dielectric layer.

3. The method as claimed in claim 1 ,

wherein the carrier contains a semiconductor material.

4. The method as claimed in claim 1 ,

wherein the functional layer is arranged between the semiconductor layer sequence and the carrier.

5. The method as claimed in claim 1 ,

wherein the functional layer extends over a whole area of the composite assembly before severing the functional layer.

6. The method as claimed in claim 1 ,

wherein the chemical method comprises fluorocarbon having at least one of octafluorocyclobutane, tetrafluoromethane, and combinations thereof; wherein the protective layer further comprises the fluorocarbon.

7. The method as claimed in claim 1 ,

wherein the separating trenches extend completely through the carrier after forming separating trenches.

8. The method as claimed in claim 1 ,

wherein forming separating trenches in the carrier along the singulation pattern is carried out after severing the functional layer by means of coherent radiation.

9. The method as claimed in claim 1 ,

wherein the composite assembly is secured on an auxiliary carrier before singulation and the semiconductor chips are present in a geometrical order on the auxiliary carrier after singulation.

10. A semiconductor chip comprising:

a semiconductor body, a carrier body, and a functional layer, which are arranged one on top of another in a vertical direction; and

a protective layer comprising slag, wherein the slag is formed along at least one side of the functional layer and along at least one side of the carrier body by a removal of a material by means of coherent radiation; and

wherein the functional layer is covered by the protective layer.

11. The semiconductor chip as claimed in claim 10 , wherein the functional layer is arranged between the carrier body and the semiconductor body.

12. A semiconductor chip comprising:

a semiconductor body, a carrier body, and a functional layer arranged between the carrier body and the semiconductor body;

a protective layer comprising slag, wherein the slag is formed along at least one side of the functional layer and along at least one side of the carrier body by a removal of a material by means of coherent radiation; wherein the functional layer on the at least one side surface of the semiconductor chip which has the traces is covered by the protective layer; and

wherein at least a portion of the semiconductor body extends completely through the protective layer.

13. The method of claim 1 , wherein the applying the protective layer occurs in the absence of a further etching step.

14. The semiconductor device of claim 12 , further comprising:

an auxiliary carrier arranged under the carrier body; and

a further functional layer arranged between the carrier body and the auxiliary carrier.