Last week during the deposition step, Chris and I discovered that part of the Cu “power cup” (piece that is bonded to target to make thermal contact with sputter gun) had eroded and coated the inside of the target shield…

Last week a set of four wafers was processed at four different RTP temperatures (1000, 950, 900, 850 C).  Unfortunately, the yield across these wafers was low due to possible metal contamination in the film and etch issues.  However, the…

For the last two weeks, we have observed that membranes have been wrinkling post-oxide strip.  After some investigation, it was determined that the cause of wrinkling was from a cracked SiO2 target in the sputter system. I also saw a…

There has been some experimentation recently on trying to form very large pores in thick membranes.  We have found that a high temperature anneal (1000 C) along with a fast ramp rate (100 C/s) w/o the susceptor can create these…

For the last three weeks, we have increased the substrate bias power from 25 W to 32 W (for both oxide and a-Si) to adress some film quality issues.  I have found that it is “harder” to open pores in…

Inspired by JP’s work with the Veeco Wyko, I attempted to fit pressure-displacement curves with the equation for thin film deformation (Vlassak and Nix 1992) for two membrane geometries: 100um x 100um and 1000um x 1000um. The relationship between displacement…

After seeing a reduction of pore size at 750 C, I decided to run three different soak times at a fixed acetylene concentration of 1 LPM.  As expected, the longer soak time resulted in more occlusion. It seems that the…

Last week I ran a series of membranes through the carbonization process at four different temperatures (600, 700, 750 and 800 C) at a fixed acetylene concentration (1 LPM).  As expected, the growth of the carbon ring around our pores…

With the new heater installed in the AJA sputter tool, the production team decided to run a set of wafers at six different chamber temperatures to re-characterize membrane morphology, mechanical strength and overall quality of material.  These films were all…

Last week I reported that carbonization can shrink pores.  This week I was able to completely occlude the pores with a change in the process recipe.  Instead of cutting off the acetylene flow before the thermal treatment, I kept the…