Why is etching a crucial step in the manufacturing process of chips in the microelectronics and semiconductor industries?
Etching processes are usually divided into two categories: wet etching and dry etching, each with its unique applicable scenarios and advantages.
Wet etching utilizes chemical reactions between liquid chemical reagents (etching solution) and the material being etched to selectively remove unwanted parts of the material surface. This process usually involves immersing the wafer to be processed in an etching solution, and precisely controlling the depth and contour of the etching by controlling parameters such as temperature, concentration, and time. Wet etching has the advantages of simple equipment and low cost, but it may not be as accurate and control complex patterns as dry etching.
Dry etching does not rely on liquid media, but uses gases (such as fluoride, chlorine, etc.) or high-energy ion beams (such as plasma) to undergo physical or chemical reactions with the material surface, thereby removing the material. Dry etching includes various techniques such as reactive ion etching (RIE), deep reactive ion etching (DRIE), and plasma etching. These technologies can provide higher etching accuracy, better vertical sidewall contour control, and more complex pattern processing capabilities, making them widely popular in manufacturing high-precision and high-performance integrated circuits.
Wet etching utilizes chemical reactions between liquid chemical reagents (etching solution) and the material being etched?
刻蚀工艺通常分为湿法刻蚀和干法刻蚀两大类,每种方法都有其独特的适用场景和优势。
湿法刻蚀利用液体化学试剂(刻蚀液)与被刻蚀材料之间的化学反应,选择性地去除材料表面不需要的部分。这一过程通常涉及将待加工的晶圆片浸泡在刻蚀液中,并通过控制温度、浓度和时间等参数,精确控制刻蚀的深度和轮廓。湿法刻蚀具有设备简单、成本低廉的优点,但在精确度和控制复杂图案方面可能不及干法刻蚀。
干法刻蚀则不依赖液体介质,而是利用气体(如氟化物、氯气等)或高能离子束(如等离子体)与材料表面发生物理或化学反应,从而去除材料。干法刻蚀包括反应离子刻蚀(RIE)、深反应离子刻蚀(DRIE)、等离子刻蚀等多种技术。这些技术能够提供更高的刻蚀精度、更好的垂直侧壁轮廓控制以及更复杂的图案处理能力,因此在制造高精度、高性能的集成电路时广受欢迎。