Methods for manufacturing semiconductor devices, and semiconductor devices

A method for manufacturing a semiconductor device, comprising:

• providing a substrate;
• forming a first conductive material layer on the substrate;
• performing plasma treatment on the first conductive material layer to form a first conductive layer, a surface area of an upper surface of the first conductive layer being greater than a surface area of an upper surface of the first conductive material layer;
• successively forming a second conductive layer, a first block layer, a third conductive layer and a fourth conductive layer on the first conductive layer;
• forming a dielectric layer on the fourth conductive layer, and forming an ohmic contact layer at a junction of the first conductive layer and the second conductive layer;
• removing a part of the dielectric layer, a part of the fourth conductive layer, a part of the third conductive layer, a part of the first block layer, a part of the second conductive layer, a part of the ohmic contact layer and a part of the first conductive layer, remaining parts of the fourth conductive layer, the third conductive layer, the first block layer, the second conductive layer, the ohmic contact layer, the first conductive layer and the dielectric layer forming an initial bit line structure;
• performing NH3/N2 plasma treatment on the initial bit line structure to form a second block layer on a sidewall of the first conductive layer and a third block layer on a sidewall of the ohmic contact layer;
• wherein, the second block layer, the third block layer and the initial bit line structure are forming a bit line structure, and, both the second block layer and the third block layer are configured to prevent metals in the ohmic contact layer from precipitation;
• and
• forming a bit line sidewall protection layer, the bit line sidewall protection layer covering a surface of the bit line structure.