论文部分内容阅读
本文描述了在VLSI研制中通过氮注入形成氮化硅层。在形成各种氮化物层的过程中,注入分子氮能量范围为5到60keV,随后在1000℃的氮中退火。描述在炉中退火前后所形成的氮化物层特性,在不同的IR、SIMS和椭圆对称测量情况中找出局部氧化掩模的有效注入条件。相对于整个注入能量范围,注入氮的最初IR峰值为815cm~(-1)。对于退火后的高能量注入来说该位置会漂移到一个较高的波长数,低能量注入峰值接近于830cm~(-1),上述均与LPCVD为氧化物峰值相比而言。此研究结果认为,低能氧化物的化学成分几乎是可用定量计算的。退火过程中浓度分布向着表面漂移,并将增高峰值区氧的浓度。从氮化物分布剖面看最大值是在表面,而在<10keV时消失。在1000℃的蒸汽中生长5300(?)氧化层进行测试这些氮化物掩模特性。剂量为5×10~(16)N_2~+/cm~(-2)离子的氮化物在注入能量低于40keV会形成有效的氧化掩模。在此实验条件下,在10keV下所形成的氮化层可认为是一个有效的氧化掩模,足以适应选择性地腐蚀SiO_2,减小“鸟嘴”尺寸为常规LOCOS的四分之一。
This paper describes the formation of a silicon nitride layer by nitrogen implantation during VLSI development. During the formation of various nitride layers, molecular nitrogen was implanted in the energy range of 5 to 60 keV and then annealed in nitrogen at 1000 ° C. The characteristics of the nitride layer formed before and after annealing in the furnace are described to find out the effective injection conditions of the local oxidation mask in different cases of IR, SIMS and ellipsometric measurement. The initial IR peak for injected nitrogen relative to the entire injected energy range was 815 cm -1. The position shifts to a higher wavelength for high energy implantation after annealing, and the low energy injection peak is close to 830 cm -1, both of which are in contrast to LPCVD for oxide peak. The results of this study suggest that the chemical composition of low-energy oxides is almost quantitatively available. During annealing, the concentration distribution drifts toward the surface and increases the concentration of oxygen in the peak area. The maximum seen from the nitride profile is at the surface and disappears at <10 keV. These nitride mask properties were tested by growing a 5300 (?) Oxide layer in steam at 1000 ° C. The nitride with the dose of 5 × 10 ~ (16) N_2 ~ + / cm ~ (-2) ions forms an effective oxidation mask when the implantation energy is lower than 40 keV. The nitrided layer formed at 10 keV under this experimental condition can be considered as an effective oxidation mask sufficient to accommodate the selective etching of SiO 2 and reduce the “beak” size to a quarter of that of conventional LOCOS.