The present invention provides a method of forming an insulating structure of a high electron mobility transistor (HEMT), firstly, a gallium nitride layer is formed, next, an aluminum gallium nitride layer is formed on the gallium nitride layer, then, a first patterned photoresist layer is formed on the aluminum gallium nitride layer, and a groove is formed in the gallium nitride layer and the aluminum gallium nitride layer, next, an insulating layer is formed and filling up the groove. Afterwards, a second patterned photoresist layer is formed on the insulating layer, wherein the pattern of the first patterned photoresist layer is complementary to the pattern of the second patterned photoresist layer, and part of the insulating layer is removed, then, the second patterned photoresist layer is removed, and an etching step is performed on the remaining insulating layer to remove part of the insulating layer again.

The present disclosure is directed to a method for forming metal insulator metal decoupling capacitors with scalable capacitance. The method can include forming a first redistribution layer with metal lines on a portion of a polymer layer, depositing a photoresist layer on the first redistribution layer, and etching the photoresist layer to form spaced apart first and second TIV openings in the photoresist layer, where the first TIV opening is wider than the second TIV opening. The method can further include depositing a metal in the first and second TIV openings to form respective first and second TIV structures in contact with the metal line, removing the photoresist layer, forming a high-k dielectric on a top surface of the first and second TIV structures, and depositing a metal layer on the high-k dielectric layer to form respective first and second capacitors.

A method for preparing a semiconductor device includes: providing a semiconductor substrate, in which a trench is formed on the semiconductor substrate, a filling layer is formed in the trench, and a void is formed in the filling layer; removing a portion of the filling layer to expose the void; forming a plug, in which the plug is configured to plug the void and extends into the void by at least a preset distance; and removing a portion of the filling layer and remaining the plug with at least a preset height until the filling layer reaches a preset thickness to form a contact hole.

Provided is a semiconductor device including a substrate, a plurality of memory cells, and at least one dummy gate structure. The substrate has a memory cell region and a dummy region. The memory cells are disposed on the substrate in the memory cell region. Each memory cell includes: adjacent two stack structures disposed on the substrate; two select gates respectively disposed outside the adjacent two stack structures; and an erase gate disposed between the adjacent two stack structures. The erase gate has a step between a topmost top surface and a lowermost top surface of the erase gate. The at least one dummy gate structure is disposed on the substrate in the dummy region.

An insulating structure of a high electron mobility transistor (HEMT) is provided, which comprises a gallium nitride layer, an aluminum gallium nitride layer disposed on the gallium nitride layer, a groove disposed in the gallium nitride layer and the aluminum gallium nitride layer, an insulating layer disposed in the groove, wherein a top surface of the insulating layer is aligned with a top surface of the aluminum gallium nitride layer, and a passivation layer, disposed on the aluminum gallium nitride layer and the insulating layer.

A planarization method including the following steps is provided. A substrate is provided. The substrate includes a first region and a second region. A material layer is formed on the substrate. The top surface of the material layer in the first region is lower than the top surface of the material layer in the second region. A patterned photoresist layer is formed on the material layer in the first region. A first etching process is performed on the patterned photoresist layer, so that the top surface of the patterned photoresist layer and the top surface of the material layer in the second region have substantially the same height. A second etching process is performed on the patterned photoresist layer and the material layer. In the second etching process, the etching rate of the patterned photoresist layer is substantially the same as the etching rate of the material layer.

A method for fabricating a semiconductor device is provided. The method includes providing a substrate, having a cell region and a logic region and including a first conductive layer as a top layer, wherein shallow trench isolation (STI) structures are disposed in the substrate at cell region and the logic region. A first dry etching process is performed to preliminarily etch the first conductive layer and the STI structures at the cell region. A wet etching process is performed over the substrate to etch the STI structures down to a preserved height. A control gate stack is formed on the first conductive layer at the cell region. A second dry etching process is performed on a portion of the first conductive layer to form a floating gate under the control gate stack at the cell region and remove the first conductive layer at the logic region.

A method for smoothing a surface of a semiconductor portion is disclosed. In the method, an intentional oxide layer is formed on the surface of the semiconductor portion, a treated layer is formed in the semiconductor portion and inwardly of the intentional oxide layer, and then, the intentional oxide layer and the treated layer are removed to obtain a smoothed surface. The method may also be used for widening a recess in a manufacturing process for a semiconductor structure.

A method of detecting a polishing endpoint includes storing a plurality of library spectra, measuring a sequence of spectra from the substrate in-situ during polishing, and for each measured spectrum of the sequence of spectra, finding a best matching library spectrum from the plurality of library spectra to generate a sequence of best matching library spectra. Each library spectrum has a stored associated value representing a degree of progress through a polishing process, and the stored associated value for the best matching library spectrum is determined for each best matching library spectrum to generate a sequence of values representing a progression of polishing of the substrate. The sequence of values is compared to a target value, and a polishing endpoint is triggered when the sequence of values reaches the target value.

An IC fabrication method includes forming a first fin on a semiconductor substrate, forming an isolation dielectric material over the first fin, and planarizing the isolation dielectric material. A top surface of the first fin is covered by the isolation dielectric material after planarizing the isolation dielectric material. The method further includes etching back the isolation dielectric material until the first fin protrudes from the isolation dielectric material.